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D 1077
OULU 2010
U N I V E R S I T Y O F O U L U P. O. B . 7 5 0 0 F I - 9 0 0 1 4 U N I V E R S I T Y O F O U L U F I N L A N D
U N I V E R S I TAT I S
S E R I E S
SCIENTIAE RERUM NATURALIUM
Professor Mikko Siponen
HUMANIORA
University Lecturer Elise Kärkkäinen
TECHNICA
Professor Hannu Heusala
MEDICA
Professor Olli Vuolteenaho
SCIENTIAE RERUM SOCIALIUM
ACTA
TELERADIOLOGY—
CHANGING RADIOLOGICAL
SERVICE PROCESSES FROM
LOCAL TO REGIONAL,
INTERNATIONAL AND
MOBILE ENVIRONMENT
Senior Researcher Eila Estola
SCRIPTA ACADEMICA
Information officer Tiina Pistokoski
OECONOMICA
University Lecturer Seppo Eriksson
EDITOR IN CHIEF
Professor Olli Vuolteenaho
PUBLICATIONS EDITOR
Publications Editor Kirsti Nurkkala
ISBN 978-951-42-6371-2 (Paperback)
ISBN 978-951-42-6372-9 (PDF)
ISSN 0355-3221 (Print)
ISSN 1796-2234 (Online)
U N I V E R S I T AT I S O U L U E N S I S
Jarmo Reponen
E D I T O R S
Jarmo Reponen
A
B
C
D
E
F
G
O U L U E N S I S
ACTA
A C TA
D 1077
UNIVERSITY OF OULU,
FACULTY OF MEDICINE,
INSTITUTE OF DIAGNOSTICS,
DEPARTMENT OF DIAGNOSTIC RADIOLOGY;
UNIVERSITY OF OULU,
FACULTY OF MEDICINE,
INSTITUTE OF BIOMEDICINE,
DEPARTMENT OF MEDICAL TECHNOLOGY
D
MEDICA
ACTA UNIVERSITATIS OULUENSIS
D Medica 1077
JARMO REPONEN
TELERADIOLOGY—CHANGING
RADIOLOGICAL SERVICE
PROCESSES FROM LOCAL TO
REGIONAL, INTERNATIONAL
AND MOBILE ENVIRONMENT
Academic dissertation to be presented with the assent of
the Faculty of Medicine of the University of Oulu for
public defence in Auditorium 7 of Oulu University
Hospital, on 10 December 2010, at 12 noon
U N I VE R S I T Y O F O U L U , O U L U 2 0 1 0
Copyright © 2010
Acta Univ. Oul. D 1077, 2010
Supervised by
Professor Osmo Tervonen
Reviewed by
Docent Tomi Kauppinen
Professor Timo Paakkala
ISBN 978-951-42-6371-2 (Paperback)
ISBN 978-951-42-6372-9 (PDF)
http://herkules.oulu.fi/isbn9789514263729/
ISSN 0355-3221 (Printed)
ISSN 1796-2234 (Online)
http://herkules.oulu.fi/issn03553221/
Cover Design
Raimo Ahonen
JUVENES PRINT
TAMPERE 2010
Reponen, Jarmo, Teleradiology—changing radiological service processes from
local to regional, international and mobile environment
University of Oulu, Faculty of Medicine, Institute of Diagnostics, Department of Diagnostic
Radiology, P.O.Box 5000, FI-90014 University of Oulu, Finland; University of Oulu, Faculty of
Medicine, Institute of Biomedicine, Department of Medical Technology, P.O.Box 5000, FI90014 University of Oulu, Finland
Acta Univ. Oul. D 1077, 2010
Oulu, Finland
Abstract
The possibilities of teleradiology to modify the radiological service process in a regional,
international and mobile setting were investigated by building new types of technical connections
and then by evaluating their feasibility.
First a teleradiology link based on low-end technology was built for primary care and hospital
settings. On evaluation, the total diagnostic agreement between the transmitted images and the
original films was 98%.
Then, a work practice-oriented approach was used to gain an understanding of the relationship
between the emerging teleradiology work practice and the newly implemented technology.
Ethnographically informed fieldwork and cooperative workshops were utilized. According to
findings, articulation work that supports the key tasks is mostly conducted at the receiving site,
and radiologists have to rely on much less information in image interpretation. The decisions made
at the sending site influence the outcome.
To study the idea of consultations between different countries, a connection utilizing the
Internet was built between university hospitals in Oulu, Reykjavik and Tromsø. After 131 images,
a suitable image compression ratio was selected. Image quality and transfer time of the 80 clinical
case readings were found to be adequate for teleradiology.
A wireless image consultation system for radiological sub-specialist consultations based on a
portable computer and a mobile phone with secure access to the hospital network was set up and
tested. The transmitted images of 68 patients were acceptable for final diagnosis in 72% of the
cases. The wireless link saved the senior radiologist a hospital visit in 24% of the cases.
A smartphone was then used to communicate computed tomography scans in a feasibility study
of 21 patient cases of brain attacks. All transmitted image series were suitable for giving a
preliminary consultation to the clinic, and in one case even a final report could be made. In a real
life clinical setting of the study with neuroradiological and neurosurgical emergencies, two
different smartphone platforms with electronic patient record integration were built in European
research projects and evaluated with sets of 115 and 150 patient cases. They were good for final
diagnosis in 38% and 40% of the cases, respectively. The concept was found to be ready for
clinical use.
Finally a survey was made showing the status and trends of the usage of eHealth applications
in Finland. The results from all the public health care providers and a representative sample of
private providers showed that in 2005, teleradiology services were used by 18/21 hospital districts
and the usage of all eHealth applications has progressed throughout the entire health care delivery
system. Teleradiology services have become an integrated part of eHealth.
Keywords: computer-supported cooperative work, eHealth, radiography technology,
telemedicine, teleradiology, wireless systems, work practice
To my family
6
Acknowledgements
This study was carried out at the Department of Diagnostic Radiology, Oulu
University Hospital, in collaboration with the Department of Medical Technology,
Institute of Biomedicine, University of Oulu, during the years 1995–2010.
I owe my deepest gratitude to my supervisor, Professor Osmo Tervonen,
M.D., Head of the Department of Diagnostic Radiology, for his encouragement
during this work. He provided me with the opportunity and positive atmosphere
to accomplish this work. He was always supportive in assuring that the work
would be finished when the time was right.
I wish to acknowledge Professor Emeritus Ilkka Suramo, M.D., the former
Head of the Department of Diagnostic Radiology, who believed in my research
topic and encouraged me to seek international collaborators and contacts early on
in an emerging cross-discipline research field.
I wish to express my gratitude to Professor Timo Jämsä, Ph.D. Head of
Department of Medical Technology, who has enabled me to extend my studies
into new research fields within his department.
I also wish to express my particular gratitude to Docent Ilkka Winblad, M.D.,
my friend and closest co-worker in the past years. In addition to generously
providing me with a lot of research knowledge, he has always kept reminding me
how important it is to accomplish tasks once they are started.
I wish to extend my warmest thanks to the official reviewers, Professor Timo
Paakkala, M.D., and Docent Tomi Kauppinen, Ph.D., for their constructive
criticism. Their efficient work and suggestions have markedly improved the
outcome.
This study would have not been possible without extensive teamwork. I wish
to thank Antero Rahtu, M.Sc. (Engineering), for showing me the basics of
teleradiology, as well as Thorgeir Palsson, M.Sc. (Engineering), Head of Clinical
Engineering and Physics at Landspitalinn, Reykjavik, Iceland, and Torbjörn Sund,
M.Sc. (Engineering), Telenor, Oslo, Norway, for showing me the possibilities of
international data networks.
I am grateful to Docent Eero Ilkko, M.D., and Docent Jaakko Niinimäki,
M.D., who have always been open for new ideas and given the best of their
knowledge and time for both scientific thinking and practical work in this study.
My sincere thanks belong to Professor Seppo Lähde, M.D., and Juhani
Laitinen, M.D., who besides taking part of this study, have been great clinical
teachers in radiology.
7
All the other collaborators deserve my sincere thanks. From the Oulu team
Professor Helena Karasti, Ph.D., Virpi Karhula, M.Sc., Docent Ari Karttunen,
M.D., Docent Antero Koivula, Ph.D., Docent Timo Kumpulainen, M.D.,
Professor Kari Kuutti, Ph.D., Pekka Jartti, M.D., Ph.D., Lasse Jyrkinen, M.Sc.
(Engineering), Eeva-Liisa Leisti, M.D., Ph.D., Professor Juhani Pyhtinen, M.D.,
Docent Markku Päivänsalo, M.D., and Docent Tarja Rissanen, M.D., Ph.D., have
taken part in various new experiments without counting their working hours.
I am grateful to Anna Vuolteenaho M.A., for the careful revision of the
language of this thesis. I would also like to thank Professor Roberto Blanco, M.D.,
and Professor Miika Nieminen, Ph.D., for taking part in the follow-up group of
this work. I also wish to thank Mrs Kaisa Punakivi, Mrs Marja-Liisa Raipola, Mrs
Leila Salo and Ms Arja Väisänen for their kind assistance with practical matters.
I express my gratitude to Virpi Honkala, M.D., chief physician at Raahe
Hospital, who has been an inspiring clinical superior and done her best to
guarantee possibilities to convert theories into practice.
The board of the Finnish Society of Telemedicine and eHealth has made up
an excellent atmosphere for discussing recent developments in eHealth. Many
thanks to all the collaborators, especially to Sinikka Salo, DDS, Ph.D., and
Principal Lecturer Anja Henner, Ph.D., for their support towards a scientific
approach, and to Arto Holopainen, M.Sc. (Engineering), for technical support.
A group of former photography enthusiasts, the Hemmos, has provided a
yearly escape from formal activities. Special thanks are due to all of them,
without forgetting Pertti Saloheimo, M.D., Ph.D., who also gave his editorial
experience for the benefit of this work.
Finally, I wish to express my warmest gratitude to my dear wife Jaana for her
support throughout the years. Without her patiently taking care of daily
responsibilities I would not have been able to concentrate on this work. My
beloved children Tiina, Tuomo and Taneli have brought delight into my life and
their music has carried me during the lonely evenings spent preparing these texts.
I also give my dearest thanks to my parents, Laura and Paavo Reponen, for their
support and guidance from early on. I am deeply sorry my mother was not able to
see the finished work.
The research was financially supported by European Commission R&D
framework programmes IV (Health Telematics) and V (Information Society
Technologies) and also by a grant from the Radiological Society of Finland, all of
which are gratefully acknowledged.
8
Abbreviations
3G
4G
AAPM
ACR
ANSI
bit/s
CCD
CDMA
CE
CEN
CR
CSCW
DCT
DPI
CT
DICOM
DF
DM
DR
DSA
EDGE
EPR
EU
EVDO
Funet
FTP
GPRS
GSM
HIS
HL7
HSCSD
HTTP
ICT
IEEE
ISDN
third-generation mobile networks
fourth-generation mobile networks
American Association of Physicists in Medicine
American College of Radiology
American National Standards Institute
bits per second, used with prefixes like kbit/s, Mbit/s, Gbit/s
charge coupled device
code division multiple access
conformité européenne, marking for European conformity
Comité Européen de Normalisation
computed radiography
computer supported cooperative work
discrete cosine transform
dots per inch
computed tomography, computerized tomography
digital imaging and communication in medicine
digital fluoroscopy
digital mammography
digital radiography
digital subtraction angiography
enhanced data rates for GSM Evolution
electronic patient record
European Union
evolution data optimized
Finnish University and Research Network
file transfer protocol
general packet radio service
global system for mobile communications
hospital information system
health level 7
high-speed circuit-switched data
hypertext transfer protocol
information and communication technology
Institute of Electrical and Electronics Engineers
integrated services digital network
9
JIF
JIRA
JPEG
bit/s
LAN
LCD
LTE
LZW
Mhz
MDD
MR
MRI
MS-DOS
NEMA
NM
NMT
NORDUnet
PACS
PC
PDA
PPP
QoS
OSI
RIS
ROC
SSL
SMS
TCP/IP
TIFF
TDMA
UMTS
US
Unix
VPN
WAN
WLAN
WWW
10
JPEG interchange format
Japan Industries Association of Radiological Systems
Joint Photographers Expert Group
bits per second
local area network
liquid crystal display
long time evolution
Lempel–Ziv–Welch
megahertz
Medical Devices Directive
magnetic resonance
magnetic resonance imaging
MicroSoft Disk Operating System
National Electrical Manufactures Association
nuclear medicine
nordic mobile telephone
Nordic Infrastructure for Research & Education
picture archiving and communication systems
personal computer
personal digital assistant
point-to-point protocol
quality of service
open systems interconnect
radiology information system
receiver operating characteristic
secure sockets layer
short message service
transmission control protocol /Internet protocol
tagged image file format
time division multiple access
universal mobile telecommunications system
ultrasound
a computer operating system (mainly for efficient workstations)
virtual private network
wide area network
wireless local area network
World Wide Web
List of original publications
This thesis is based on the following original articles, which are referred to in the
text by their Roman numerals:
I
II
III
IV
V
VI
VII
Reponen J, Lähde S, Tervonen O, Ilkko E, Rissanen T & Suramo I (1995) Low-cost
Digital Teleradiology. Eur J Radiol 19: 226–231.
Karasti H, Reponen J, Tervonen O & Kuutti K (1998) The teleradiology system and
changes in work practices. Comput Methods Programs Biomed 57(1–2): 69–78.
Reponen J, Palsson T, Kjartansson O, Ilkko E, Störmer J, Päivänsalo M, Pyhtinen J,
Laitinen J, Eiriksson A & Brekkan A (1995) Nordic Telemedicine Consultation
Network Using Internet. Proceedings of CAR ´95 Computer Assisted Radiology and
Surgery. Berlin, Springer Verlag: 723–728.
Reponen J, Ilkko E, Jyrkinen L, Karhula V, Tervonen O, Laitinen J, Leisti E-L,
Koivula A & Suramo I (1998) Wireless radiological consultation with portable
computers. J Telemed Telecare 4: 201–205.
Reponen J, Ilkko E, Jyrkinen L, Tervonen O, Niinimaki J, Karhula V & Koivula A
(2000) Initial experience with a wireless personal digital assistant as a teleradiology
terminal for reporting emergency computerized tomography scans. J Telemed
Telecare 6(1): 45–9.
Reponen J, Niinimäki J, Kumpulainen T, Ilkko E, Karttunen A & Jartti P (2005)
Mobile teleradiology with smartphone terminals as a part of a multimedia electronic
patient record. Int Congr Ser 1281: 916–921.
Reponen J, Winblad I & Hämäläinen P (2008) Current status of national eHealth and
telemedicine development in Finland. Stud Health Technol Inform 134: 199–208.
11
12
Contents
Abstract
Acknowledgements
7
Abbreviations
9
List of original publications
11
Contents
13
1 Introduction
15
2 Review of the literature
17
2.1 Definition and development of teleradiology.......................................... 17
2.2 Change of paradigm: the digital image ................................................... 20
2.3 Required components of a teleradiology system..................................... 21
2.3.1 Image-sending station ................................................................... 21
2.3.2 Transmission network................................................................... 22
2.3.3 Image review station..................................................................... 23
2.3.4 Development of workstation and digitizer technology ................. 23
2.4 Recent communication technology developments .................................. 24
2.4.1 Wired connections ........................................................................ 24
2.4.2 Connection of networks; the Internet ........................................... 25
2.4.3 Mobile communication ................................................................. 26
2.5 DICOM-standard .................................................................................... 27
2.5.1 IHE integration profiles ................................................................ 28
2.6 Medical Devices Directive ...................................................................... 30
2.7 Image compression ................................................................................. 30
2.8 Data safety .............................................................................................. 32
2.9 Work process ........................................................................................... 33
2.10 Motivation of teleradiology..................................................................... 33
2.10.1 Effectiveness of teleradiology ...................................................... 33
2.10.2 Quality aspects ............................................................................. 35
2.11 Use of teleradiology ................................................................................ 36
2.11.1 Point to point consultations .......................................................... 36
2.11.2 Regional service concept .............................................................. 36
2.11.3 Mobile teleradiology .................................................................... 37
2.11.4 International teleradiology consultations...................................... 38
2.12 Concept of eHealth.................................................................................. 39
2.12.1 National initiatives for electronic patient documents ................... 40
2.12.2 EU cross border telemedicine initiatives ...................................... 40
13
2.12.3 Teleradiology as a part of eHealth services .................................. 41
3 Purpose of the study
43
4 Subjects and methods
45
4.1 Low-end technology teleradiology.......................................................... 45
4.2 Work practise analysis ............................................................................. 46
4.3 Internet teleradiology .............................................................................. 49
4.4 Mobile PC teleradiology ......................................................................... 50
4.5 Smartphone teleradiology ....................................................................... 54
4.5.1 Feasibility study............................................................................ 54
4.5.2 Clinical study ................................................................................ 55
4.6 Integration of teleradiology as a part of eHealth services ....................... 57
5 Results
59
5.1 Low-end technology teleradiology.......................................................... 59
5.2 Work practice analysis ............................................................................ 60
5.3 Internet teleradiology .............................................................................. 64
5.4 Mobile PC teleradiology ......................................................................... 66
5.5 Smartphone teleradiology ....................................................................... 67
5.5.1 Feasibility study............................................................................ 67
5.5.2 Clinical study ................................................................................ 68
5.6 Integration of teleradiology as a part of eHealth services ....................... 70
6 Discussion
75
6.1 Low-end technology teleradiology.......................................................... 76
6.2 Work practise analysis ............................................................................. 79
6.3 Internet teleradiology .............................................................................. 81
6.4 Mobile PC teleradiology ......................................................................... 83
6.5 Smartphone teleradiology ....................................................................... 85
6.5.1 Feasibility study............................................................................ 85
6.5.2 Clinical study ................................................................................ 89
6.6 Integration of teleradiology as a part of eHealth services ....................... 93
6.7 General discussion – from teleradiology to eHealth and beyond ............ 97
7 Summary and Conclusions
101
8 References
103
Original publications
119
14
1
Introduction
Teleradiology services have long been performed with special solutions (Gitlin
1986, Batnitzky et al. 1990, Dwyer et al. 1991, Goldberg et al. 1993), but
gradually connections came to be established with far less effort and cost than
before (Dohrmann 1991, Yamamoto et al. 1996, Berry & Barry 1998, Engelmann
et al. 2002). The advances in telecommunication and computer technology have
given us widely standardized tools, which can be applied into clinical practice
(Henri et al. 1997, Hussein et al. 2004).
Teleradiology started as point-to-point connections using either telephone or
dedicated data network connections (Thrall 2007a, Huang 2010). Two major
advances forward have been the Internet (Caramella 1996) and mobile
communication technology (Yamamoto 1995). They pose new challenges by
linking experts quickly with patient information and breaking the barriers of time
and physical hospital buildings. The Internet has even the potential to link
international institutions to obtain secondary opinion (Kovalerchuk et al. 1998,
Wagner 2002). Mobile phones have the potential of bringing a radiology
workstation to a radiologist’s pocket (Yamamoto & Williams 2000). However, the
technical feasibility of the Internet and mobile communication technology for
clinical radiology practice needs to be assessed. New concepts have to be
developed both in order to connect these tools to the hospital information systems
(HIS) in an applicable and secure manner and to find the target medical areas and
workflows that will benefit the most from these advances (Arenson et al. 2000,
Benjamin et al. 2010). This means combining both engineering and medical
knowledge in an effective way.
The work process in a radiological department even within one institution is
complicated by many successive steps (Siegel & Reiner 2002), and the utilization
of the new telemedical workflow in this environment can therefore be
problematic. The amount of teamwork needed to establish the final radiological
report is extensive (Siegel & Reiner 2002). There are many challenges when we
progress from an analogue to a digital environment (Reiner et al. 1996). These are
related to technical, practical and quality aspects (Protopapas et al. 1996, Siegel et
al. 1997, Soegner et al. 2003b). A work practice analysis can reveal aspects,
otherwise hidden, that can be used to develop the teleradiology process chain
(Abbot & Sarin 1994, Karasti 1997).
When health care information processing turns digital, teleradiology becomes
a natural part of eHealth (Harno 2004, Reponen 2008), which by definition
15
combines local and distant information and communication solutions in health
care, such as electronic patient records (EPR), HIS, picture archiving and
communication systems (PACS) and direct services for citizens under one
umbrella (World Health Organization 2010). Before this study, the situation and
the progression rate of digital image transfer in Finland has not been well known.
Better knowledge of the present state also gives us tools to take the next logical
steps and develop even international cross-border links (Ross et al. 2010) for
consultations.
The purpose of this study is to evaluate the use and implementation of
teleradiology, more precisely the following: whether low-end technology could
combine acceptable image quality and reasonable costs for primary care centres
and local hospitals, whether there will be noticeable changes in the work
processes when two different institutions start to work together, whether
international teleconsultations using data networks could link together different
institutions in a feasible manner, whether new ubiquitous communication tools,
such as mobile data communication, are suitable for radiological purposes,
whether smartphones could be used for image interpretations, and finally, to chart
the usage status of teleradiology and digital radiology in the electronic health care
(eHealth) domain in Finland in general.
This study will discuss important research steps and achievements from
traditional point-to-point teleradiology to mobile and internationally networked
services over a time span of more than ten years. As some of the sub-topics in this
study were among the earliest published work in this field, the results will draw a
natural development path and summarize the newest trends in the rapidly
developing field of teleradiology as part of the present electronic health care
environment.
16
2
Review of the literature
2.1
Definition and development of teleradiology
Teleradiology is one of the most established and most widely used forms of a
larger entity called telemedicine (Wootton 1996, Roine et al. 2001, Ruotsalainen
2010). One of the early comprehensive definitions of telemedicine is that of
Dripps et al. (1992), stating that telemedicine is the investigation, monitoring and
management of patients and staff using systems which allow ready access to
expert advice no matter where the patient is located.
Telemedicine is actually an umbrella term that encompasses any medical
activity involving an element of distance (Wootton 2001). A few years ago the
term telemedicine began to be supplemented by the term telehealth (Watanabe et
al. 1999, Krupinski et al. 2002), which was thought to be more “politically
correct”, but since the year 2000 or thereabouts this too has been overtaken by
even more fashionable terms, such as online health and e-health (or eHealth)
(Wootton 2001).
In a narrow definition, teleradiology has been defined as obtaining a
specialist opinion by transmission of digital x-ray images to a radiologist
elsewhere (often in a tertiary centre) (Wootton 2001).
A wider definition by the Canadian Association of Radiologists (2008) says
that teleradiology is the electronic transmission of diagnostic imaging studies
from one location to another for the purposes of interpretation and/or consultation.
It is mentioned that this definition covers both interfacility PACS networks as
well as remote teleradiology.
American College of Radiology (ACR) definition (2002) adds educational
aspects by saying that teleradiology may allow even more timely interpretation of
radiological images and give greater access to secondary consultations and
improved continuing education. Images may be viewed simultaneously by users
in different locations. According to ACR, when appropriately utilized,
teleradiology can improve access to high-quality radiological interpretations and
thus significantly improve patient care.
The following is a short practical definition suitable for most purposes:
Teleradiology is the ability to obtain images in one location, transmit them over a
distance, and view them remotely for diagnostic or consultative purposes (Thrall
2007a).
17
The earliest mention of teleradiology dates back to 1929, when two dental
radiographs were transmitted in the USA with the help of telegraph to a distant
location. The image quality was cited to be good enough for dental fillings to be
seen, according to an anonymous article published in the Journal of Dental
Radiography and Photography (1929). This realized the hopes raised by an earlier
anonymous article in published in the the New York Times (1907) describing the
pioneering telephotograph work of professor Arthur Korn from Munich and
predicting the coming wonders: “Lovers conversing at a great distance will
behold each other as in the flesh. Doctors will examine patients’ tongues in
another city, and the poor will enjoy visual trips wherever their fancy inclines.”
The earliest generation of clinical teleradiology starting from the late 1950s
was based on the transmission of analogue TV images with either close circuit or
broadcast technology, using either real time or videotaped images (Jutras 1959,
Murphy & Bird 1974, Murphy et al. 1970, Andrus et al. 1975a, Andrus et al.
1975b). However, the image quality was inadequate compared with the quality of
film images (Page et al. 1981, Curtis et al. 1983). In addition, the working
logistics were not optimal, as the images had to be sent one by one and the cost of
a dedicated installation was high. Once these limitations were recognized, most of
the pioneering projects of clinical teleradiology were terminated (Thrall 2007a).
Then, in the early 1980s, attention turned to computer-based approaches to
telemedicine, with a shift in interest from real-time television applications to
“store-and-foreward” methods, in which data are collected in digital form at an
initiating site and aggregated and stored for subsequent transmission to a
receiving site (Gayler et al. 1981, Lufkin et al. 1983, Gitlin 1986, Thrall 2007a).
Teleradiology systems became commercially available in the 1980s from a
number of vendors, but in retrospect, they were very limited in terms of quality
and scalability (Markivee & Chenoweth 1990, Thrall 2007a). So-called cameraon-a-stick systems enjoyed a brief period of popularity mostly for hospital-tohome applications to provide “after-hours” coverage (Bradley 2008). The
approach entailed photographing or videographing selected hard-copy images for
subsequent digitization and image transfer (Mun et al. 1995, Thrall 2007a).
In the Nordic countries the first clinical teleradiology connection was
established in Sweden in the early 1980s. A digital system for transmission of
images over telephone lines using a 256 × 256 and 6 bit deep matrix from a video
camera providing communication between a county hospital and a university
hospital was presented. Transmission of computed tomography (CT) images was
performed without significant degradation of image quality while deterioration of
18
image quality was noticed when conventional films were transmitted. The
consultations gave clinically valuable information to the transmitting radiologist
in approximately 50 percent of the cases. (Nilsson et al. 1986.) However, the
limited image quality and relatively slow image transmission prevented the
diffusion of this method (Olsson 1991).
In Finland, distance teleradiology using the national television broadcasting
network was tested briefly in 1969 (Soila 1970), but the results were only
published in a non-scientific newspaper and magazine articles (Reponen 2004).
Clinical teleradiology started when a videocamera-based photophone device with
a 529 × 440 pixel and 8 bit deep matrix was taken into use between Jyväskylä
central hospital and Kuopio University Hospital in 1989. CT images of
neurosurgical emergencies were sent; each scanned image was transmitted over
telephone lines in 30 seconds. According to users, the equipment saved its
purchasing costs because transportation of patients could be avoided. (Vuorela &
Puranen 1994.) More capable teleradiology, with film scanners and Unix
computer workstations with a 1024 × 1024 and 2048 × 2048 pixel matrix that
were still expensive at that time, was launched in Finland in the early 1990s
(Viitanen et al. 1992) and evaluation results showed acceptable quality for chest
images (Kormano et al. 1994, Korsoff et al. 1995). Lower resolution
microcomputer-based teleradiology with a 512 × 512 pixel and 8-bit image matrix
was also evaluated and found sufficient for consultation with most conventional
radiographs in daily practice (Paakkala et al. 1991). In this study, images from
372 conventional roentgen examinations were digitized and transmitted via a 64
Kbits/s telephone line from a rural health centre to a university hospital, where
they were interpreted by two radiologists. Slight deterioration of image quality
was noticed, although the images were non-diagnostic only in a few cases.
According to the authors, a system based on a 1024 × 1024 pixel matrix is
desirable, however.
Modern teleradiology thus began to develop after the introduction of digitized
images. The early digitized systems captured video images with a 256 × 256 to
512 × 512 pixel matrix and a 6- to 8-bit dynamic range, while more sophisticated
laser scanners enabled resolution of up to 4096 × 4096 pixel and 12 bit- grey
scale (Jelaso et al. 1978, Goldberg et al. 1993). However, the approaches were
cumbersome, and images were still handled one at a time (Thrall 2007a).
Other obstacles for widespread use of teleradiology were the relatively low
performance and high cost of computer systems available (Batnitzky et al. 1990),
high costs of data transmission (Dwyer et al. 1991), and lack of practical and
19
affordable digital image handling systems including high-resolution workstations
at originating and receiving sites (Thrall 2007a).
2.2
Change of paradigm: the digital image
One of the key enabling factors for teleradiology has been the change in the
overall paradigm of how radiological images are made and used. Since the
invention of new X-rays (Röntgen 1895), the imaging process was for nearly a
hundred years based on photographic chemistry and physical images. These
images had to then be copied or transmitted via courier if their presence at another
local was needed.
New imaging modalities, like tomographic nuclear medicine (NM) imaging
with computerized image display and storage in the 1960s and CT in 1971, were
digital from the beginning and paved way to a digital medical image, which
consisted of computer-made measurement results and had only a representation as
a physical image (Langan & Wagner 1969, Thrall 2005, Beckmann 2006).
Magnetic resonance imaging (MRI or MR), digital subtraction angiography
(DSA), digital fluoroscopy (DF), ultrasound (US) with digital image capture
followed soon after, and finally computed radiography (CR), digital radiography
(DR) and digital mammography (DM) signalled the start of the digital age,
making the computerized image commonplace (Kiuru et al. 1991b, Thrall 2005).
First, these digital modalities revolutionalized image acquisition, resulting
gradually in digital storage and transmission of images in everyday practice.
PACS took care of the images (Huang et al. 1988, Taira et al. 1988, Kiuru et al.
1991a, Viitanen et al. 1991), while radiology information systems (RIS) managed
the radiological workflow and information exchange with the other components
in the HIS (Kotter & Langer 1998, Kinsey et al. 2000). As radiologists’ working
environment has moved away from a lightbox to a computer workstation,
teleradiology is no longer an extraordinary task; it is actually one of the normal
instruments of conducting radiological work. The parallel development of digital
imaging and PACS has thus given a push forward for teleradiology, too
(Benjamin et al. 2010).
20
2.3
Required components of a teleradiology system
A basic teleradiology system consists of three major components:
1.
2.
3.
An image-sending station
A transmission network
A receiving/image review station.
Patient images are electronically encoded in a digital format at the sending station,
sent via the transmission network, and received, viewed and possibly stored at the
review station. (Kumar S., 2008.) A generic teleradiology set-up is shown in
figure 1.
Satellite
Microwaves
Film
Digitizer,
(Video,
Laser,
CCD)
Mobile
data
Images
Internet
DICOM
Images,
TXT
Teleradiology workstation
or
Direct
Digital
Capture
Formated
image data /
transmission
system
HIS/
RIS/
EPR
Patientrelated
information
WAN
Network
access
controller
Security
Controller
DSL
ISDN
Network
access
controller
Management
Software
Security
Controller
Storage
/ PACS
Phone
Report
transmitter
Report
receiver
Fax/Phone
SENDING SITE
Phone line
DATA NETWORK
Links: billing,
HIS, RIS
Fax/Phone
RECEIVING SITE
Fig. 1. Generic Teleradiology component set-up (Huang 2010, Kalyanpur et al. 2004,
Kumar 2008, Lee et al. 1999). The components are explained in more detail in the
adjacent text.
2.3.1 Image-sending station
At the image-sending station images are captured into digital format with a
digitizer, if originally stored on x-ray film. A laser film digitizer or a CCD (charge
coupled device) film scanner is usually used for this purpose. Today, with most of
the images already in digital DICOM (digital imaging and communication in
21
medicine) format, a direct digital output from digital modalities (CR, CT, DF, DM,
DR, DSA, MR, US) is utilized. (Huang 2010.) For older devices, also video frame
grabbers are used (Kroeker et al. 2000).
If a digital connection to HIS and RIS exists, this information is also
combined with relevant images and sent to the receiving site (Huang 2010).
Otherwise a fax connection or even a telephone connection can be used to
communicate the relevant patient information (Dunne & Dunne 2004). For image
and related data communication, it is advantageous to convert the data to the
industry standard because multiple vendors’ equipment is used in the
teleradiology chain. Specifically, the DICOM and TCP/IP (Transmission control
protocol/Internet protocol) standards should be used for image data
communication. (Huang 2010.)
2.3.2 Transmission network
Communication networks are essential for teleradiology. The networks can
basically be wired or wireless. The simplest wired solutions are telephone lines or
digital ISDN (integrated services digital network) lines that can be used as pointto-point connections with the help of a modem. They are also known as dial-up
connections, because they are established as need arises. Their security
requirements are less stringent, because there are no other partners in the
communication pathway. Their usable speed starts from 9.6 kbit/s for a modem
connection and 64 kbit/s for a one-channel ISDN connection. ISDN connections
can be multiplied; a typical setting uses 2 to 6 parallel channels with a speed of
128 to 384 kbits/s. (Lear et al. 1989, Stewart et al. 1992, Huang 2010.)
Wide area network (WAN) connections are fixed connections between local
area networks (LAN) in different institutions. They typically provide higher
speeds and more reliable connections. A lower-cost solution to WAN connection
is using DSL (Digital Subscriber Line) at the customer site of the connection. A
specific type of WAN connection is the Internet, which technically in most cases
uses WAN backbone, but includes the possibility to establish connections more
easily, even on an ad hoc basis. (Arenson et al. 2000, Huang 2010.)
Wireless network connections for teleradiology include satellite transmission,
microwave transmission and mobile phones connections. Satellite connections are
used directly or as part of WAN connections. Microwave transmission usually
involves direct point-to-point connections. Mobile phone network connections are
22
based on the data transfer capability of the operator lines and are usually
connected to LAN at the sending site. (Lamminen 1999, Huang 2010.)
The recent developments of WAN and mobile phone networks are discussed
in more detail in the next chapter.
2.3.3 Image review station
For a teleradiology review system, workstations with high-end 1024 × 1024 pixel
resolution (1 K) monitors for cross-sectional images and workstations with
multiple 2048 × 2048 pixel resolution (2 K) monitors have been recommended
for CR and DR (digital radiography) primary diagnosis (Huang 2010). As the
radiology workflow has turned digital, the American Association of Physicists in
Medicine (AAPM) has published requirements for image reading displays in
general PACS environment, and the current recommendations include not only
definitions of display resolution, but also definitions of other display
characteristics, such as luminance, as well as recommendations for image reading
environments and quality assurance including DICOM calibration of the displays
(Samei et al. 2005a, Samei et al. 2005b). The AAPM recommendations make no
difference between teleradiology or local reading, but they do distinguish quality
requirements between displays used for primary diagnosis and secondary
consultation. In Finland, the Radiation and Nuclear Safety Authority (STUK) has
published a Guide for Quality Control of X-ray equipment in Health Care (2008)
which covers also image display monitors and required steps in quality
maintenance. More recently, Liukkonen has published a thesis (2010) which can
be used as a primer for display requirements.
The workstation should include local storage for images and user-friendly
software to manage and display the images and relevant patient data if available.
Ideally, the teleradiology workstation should be connected to the local PACS for
image store and comparison image retrieval. For the expert centre, administrative
tools for reporting and billing are also necessary. (Huang 2010.)
2.3.4 Development of workstation and digitizer technology
In the early days of digital medical images, the concept of high-quality
teleradiology consisted of laser film scanners with large scanning matrix like
2048 × 2048 pixel resolution and high-end computer workstations together with
fast connection lines. (Batnitzky et al. 1990, Stewart et al. 1992, Goldberg et al.
23
1993.) The costs of such a system could be considerable up to the level of USD
200,000. (Dwyer et al. 1991).
The development of computer and software technology made it possible to
achieve acceptable computational power with more commonly available personal
computers (PC) and to substitute dedicated software with more general
components (Yamamoto et al. 1993, O'Sullivan et al. 1997). CCD film scanner
technology has also progressed so as to produce image quality that is getting close
to the quality of the more expensive laser film scanners (Boland 1998, Calder et
al. 1999).
2.4
Recent communication technology developments
Teleradiology requires efficient and affordable communication networks. The
access to fast computer networks is now easier than before, and interestingly
enough, open networks like the Internet as well as mobile data communication
provide new possibilities.
2.4.1 Wired connections
Teleradiology connections first started with modem-based telephone lines, after
which they developed into digital ISDN connections and the high-capacity digital
networks that are readily available today (Kumar 2008).
Institutions can hire fast WAN connections speeds in the magnitude of 1 to
155 Mbit/s and more between their local networks. The costs rise in proportion to
network speed. These WAN connections are established together with a telecom
operator, and appropriate security measures are taken. There is a possibility to
purchase a guaranteed bandwidth or quality of service (QoS) in order to have a
constant transfer speed. (Huang 2010.) These high-capacity networks are mostly
used for image traffic between PACS archives and also for regional teleradiology
and image transfer networks (Bradley 2008).
Private persons can also lease DSL (Digital Subscriber Line) or optic cable
connections to their homes with capacities from 256 kbit/s to 20 Mbit/s. Even
though the costs are lower, these lines are still suitable for teleradiology. (Huang
2010.)
24
2.4.2 Connection of networks; the Internet
The Internet is a global system of interconnected computer networks that use the
standard Internet Protocol Suite (TCP/IP) to serve billions of users worldwide. It
is a network of networks that consists of millions of private, public, academic,
business and government networks of local to global scope that are linked by a
broad array of electronic and optical networking technologies. The Internet carries
a vast array of information resources and services, most notably the inter-linked
hypertext documents of the World Wide Web (WWW) originally developed in
1989 at CERN, the European Organization for Nuclear Research, and the
infrastructure to support electronic mail. (Ahonen 2008, Bergh et al. 2000.)
Started as the US military network Arpanet in the late 1960s, the Internet with
its protocols has now achieved a global position. In Finland, university networks
were started in the 1970s, and in 1983 the Finnish University and Research
Network (Funet) project was founded. The Nordic countries were forerunners in
Europe by establishing a joint NORDUnet research network in 1985. The
NORDUnet network had the benefit of being neutral to networking protocols,
which enabled researchers to use the Internet ahead of central European countries
like Germany, England, France or the Netherlands. In 1988, NORDunet was
actually the first network outside the USA to have a connection to Internet.
Researches in the Nordic countries had thus better opportunities for international
collaboration. (Ahonen 2008.)
After the Internet was made publicly available outside the research
community as well in the mid-1990s, there was increasing interest in its use for
medical information transfer. For teleradiology, the possible benefits of the
Internet are related to the ease of making connections, even internationally
(Boland 1998). There is however no QoS on Internet connections (Huang 2010).
Because of slow speeds and security concerns, the Internet and more specifically,
WWW, was seen a tool for educational material delivery and discussion
(Scarsbrook et al. 2005). Patient treatment over the network was considered to
require more advanced secured tunnelling protocols and more efficient ways of
forwarding large amounts of data (Bergh et al. 2003).
25
2.4.3 Mobile communication
Mobile data networks
Wireless networks became meaningful for medical purposes after they covered a
reasonably large area. The Nordic Mobile Telephone (NMT) network was the first
fully automatic wireless network that provided multinational roaming from
country to country and could be used for data transfer (Ali-Yrkkö & Hermans
2004, Reponen & Niinimäki 2006). One of the benefits of the NMT network was
that its 450 Mhz variant also covered more distant areas of Finland (Judén &
Kuokkanen 2000).
Although the GSM (global system for mobile communications) developed in
Europe is the most widely distributed second-generation mobile network,
different technologies are used in the US and Japan, making them incompatible
(Istepanian et al. 1998, Istepanian et al. 1999). Interestingly, the first GSM call
ever was made in Finland in 1991 (Elisa Oyj 2004, GSM Association 2010). One
benefit of GSM for medical use is that digital data transfer was defined as one of
its basic functions from the beginning. The main limitation of circuit switched
GSM data networks is the data transfer speed, which is realized in commercial
services in the magnitude of 9.6 to 14.4 kbit/s (high-speed), although data rates up
to 57.6 kbit/s would be theoretically possible (Joutjärvi et al. 2000, Tachakra
2003).
The next generation of data networks, the so-called 2.5 generation, namely
packet-switched GPRS (general packet radio service) and its variant EDGE
(enhanced data rates for GSM evolution), provide theoretical maximum data
transmission speeds of up to 114 and 473.6 kbit/s, respectively. In practice, the
effective speed is lower. The increase in speed is substantial compared to original
GSM data transfer, enabling much faster data transmission. Another benefit of
these packet-switched networks is that they allow the usage of Internet protocols
in data transmission, which makes system design much easier for mobile data
applications. Finally, third-generation (3G) UMTS (universal mobile
telecommunications system) networks have developed data transfer speeds to a
level that makes mobile Internet usage feasible. (Ericsson 2009.)
All these variants of data networks are currently available, GPRS coverage
being available practically in all parts of Finland and in most European countries,
its faster EDGE variant having a slightly more limited coverage. Fast 3G
26
networks, even though available world-wide, are still concentrated in the most
densely populated regions. (GSM Association 2009.)
Handheld terminal devices
Thanks to advances in processor and display technology, handheld computers or
personal digital assistants (PDAs) gained a market in the 1990s (Yamamoto 2000,
Pyrros & Yaghmai 2008). Mostly equipped with a black and white display and a
slow processor, they were capable of displaying elementary images. The variants
included devices from manufactures like Psion, Ericsson, Palm and Sharp.
Networking capacity was added to some of the devices via a cable modem or a
network card, or with a GSM data card or a cable connection to a mobile phone
(Tachakra 2003). The concept thus resembled that of a laptop computer with
networking capabilities.
A revolution took place in 1996 when Nokia Corporation introduced the first
integrated communicator device, which had a handheld PDA-type computer and a
GSM phone with digital data transfer capabilities in one package (PDAdb.net
2007). The phone functions included advanced SMS messaging, and the PDA
functions included office solutions as well as typical PDA applications like
calendar and voice recording. The most important factor was the possibility to
make new software applications for the device and also to guide it remotely. This
opened the possibility of using it as a terminal device for various computer and
data network applications. The display was sharp and larger than in ordinary
mobile phones. The limitation was its grey scale, but with proper software to
compensate for this, it was possible to use it for displaying grey-scale images.
2.5
DICOM-standard
Radiology has the benefit of standing in the crossroads of medicine and
technology. The cost of equipment is high, so the investments should be
economically feasible. In the digital imaging domain, it was very soon noticed
that no single vendor could provide a comprehensive imaging system for
customers. The integration of different imaging systems is expensive and timeconsuming and the business prognosis was poor if customers could not trust the
vendors. This prompted the ACR and the National Electrical Manufacturers
Association (NEMA), with input from various vendors, academia, and industry
groups, to work together to come up with standards of interoperability in medical
27
imaging from 1983 on, and published finally the DICOM standard in 1993
(NEMA 2010).
DICOM is a standard that is a framework for medical-imaging
communication. Based on the open system interconnect (OSI) reference model,
which defines a 7-layer protocol, DICOM is an application-level standard,
meaning that it exists inside layer 7 (the uppermost layer). It is referred to as
“version 3.0” because it replaces versions 1.0 (published in 1985) and 2.0 of the
standard (published in 1988) previously issued by ACR and NEMA known as the
“ACR-NEMA” standard (Kiuru 1993, NEMA 2010).
DICOM provides standardized formats for images, a common information
model, application service definitions and protocols for communication in
medical imaging in general, not only in radiology (NEMA 2009).
DICOM is a cornerstone standard in medical imaging, and very rapidly after
its launch in 1993 it replaced local European and Japanese standardization
initiatives. It is now developed in liaison with other standardization organizations
including CEN TC251 (European Committee for Standardization, Technical
Committee 251) in Europe and JIRA (Japan Industries Association of
Radiological Systems) in Japan, with review input from other organizations
including the IEEE (Institute of Electrical and Electronics Engineers), HL7
(Health level 7) and ANSI (American National Standards Institute) in the USA.
(NEMA 2009.)
One of the factors leading to rapid implementation of the DICOM standard
was commitment on the part of end-users. When DICOM became a requirement
in released calls for tender, new equipment and software soon complied with the
standard and made more complicated integration possible after the latter half of
the 1990s. (Kotter & Langer 1998, Kinsey et al. 2000.)
Because the standard enabled various vendors to work together, the medical
imaging sector has been a forerunner in digital patient data usage. A common
standard has increased the market sector and has made it possible for so-called
third party vendors to enter the market with new innovations.
2.5.1 IHE integration profiles
DICOM is in no way perfect; there is quite a lot of freedom in its implementation,
which is why a new initiative called IHE (Integrating the Healthcare Enterprise)
has been established (Oosterwijk 2004). The purpose of IHE is not to create a
new standard, but to develop further so-called integration profiles, which describe
28
how everyday tasks are best performed with existing equipment and available
standards, such as the imaging standard DICOM and the medical record
messaging standard HL7 (Channin 2001). IHE has reached a critical mass in
product support, enabling a significantly higher level of interoperability compared
to former system installations. Integration profiles in particular allow broad
implementation and useful extension of existing and newly developed IT systems
in healthcare (Wein et al. 2005).
IHE is organized across a growing number of clinical and operational
domains. Each domain produces its own set of Technical Framework documents,
in close coordination with other IHE domains. Currently in 2010 there are nine
different domains. In the radiology domain there are 19 IHE profiles that have
been published in trial implementation or final text versions. For example a
profile called Cross-enterprise Document Sharing for Imaging (XDS-I) extends
XDS-profile (which registers and shares electronic health record documents
between healthcare enterprises) to share images, diagnostic reports and related
information across a group of care sites (IHE 2010). Titles of the radiology
domain profiles are presented in Table 1.
Table 1. Titles of the published radiology domain IHE integration and interoperability
profiles in 2010. Detailed up-to-date description of the functions of each profile can be
found at http://www.ihe.net/Profiles/.
Content Profiles
Workflow and Infrastructure Profiles
Consistent Presentation of Images (CPI)
Scheduled Workflow (SWF)
Key Image Note (KIN)
Patient Information Reconciliation (PIR)
Nuclear Medicine Image (NM)
Post-Processing Workflow (PWF)
Mammography Image (MAMMO)
Reporting Workflow (RWF)
Evidence Documents (ED)
Cross-enterprise Document Sharing for Imaging (XDS-I)
Simple Image and Numeric Report (SINR)
Portable Data for Imaging (PDI)
Teaching File and Clinical Trial Export (TCE)
Import Reconciliation Workflow (IRWF)
Image Fusion (FUS)
Presentation of Grouped Procedures (PGP)
Charge Posting (CHG)
Access to Radiology Information (ARI)
Audit Trail and Node Authentication (ATNA)
Product vendors test the interoperability of their products in so called
Connectathon events. The results are then published in an open database (IHE
Europe 2010).
29
Development of these standards and integration profiles has been important
in also making teleradiology an extension of existing imaging networks, thus
helping its distribution as a health care service (Hussein et al. 2004).
2.6
Medical Devices Directive
Another form of coordinating regulation, which will in the future have an impact
on software used for teleradiology is the Medical Devices Directive (MDD). It is
a safety regulation that discusses the responsibilities of the manufacturer, the user
and the authorities. More recently, Directive 2007/47/EC (2007) amended the
definition of the term “medical device” used in Directives 90/385/EEC (1990)
and 93/42/EEC (1993). Recital 6 of Directive 2007/47/EC (2007) states that “it is
necessary to clarify that software in its own right, when specifically intended by
the manufacturer to be used for one or more of the medical purposes set out in the
definition of a medical device, is a medical device”. In Finland, the corresponding
update in legislation of medical devices came into effect on 1st July 2010
(L 629/2010).
An important implication of these above mentioned regulations is that
software products in medical device categories should fulfil the essential
requirements and their risk class has to be classified. Depending on risk class,
there are different evaluation steps before the product can receive a CE mark
(European conformance marking) and enter the market. The regulations promote
the safety and quality of the products and give users a mechanism to report any
serious problems.
The Swedish Medical Products Agency has published a guidance report
(Läkemedelsverket 2009) on how to classify various IT systems. This report has
been a basis for the work of the European Union (EU) Medical Devices Expert
Group, which is preparing European guidelines on this topic. According to the
guidance report, telemedicine programs, including teleradiology programs, are
considered to be not less than risk class I medical devices. The same implies to
software products running PACS when images are viewed and transmitted and to
RIS when information is used for treatment planning of individual patients.
2.7
Image compression
Digital images can be compressed in order to decrease the file size. This has the
benefit of decreasing either the storage space or the bandwidth needed. The latter
30
aspect is related to required network capacity and image transfer times. The
general rule is that the more capacity is needed, the more it costs and the more
time image transfer takes. (Logeswaran 2008.)
As access to affordable bandwidth has increased, the importance of image
compression has decreased in normal consultation settings. In most the cases, a
full uncompressed DICOM radiographic image can be sent for a consultation.
However, image compression is still an issue if wireless networks are used for
mobile terminals and if images are sent over otherwise narrow bandwidths, such
as satellite connections. In addition, new modalities like multislice CT, MRI and
DM produce image packages that are transmitted slowly if uncompressed.
(Logeswaran 2008.)
There are basically two types of compression, lossless and lossy (Kajiwara
1992). The first typically results in 1:2 or 1:3 gain in image size, while lossy
compression for medical purposes can be used without noticeable visual loss with
resolutions such as 1:7 to 1:40, depending on the modality and type of images
(Savcenko et al. 1998, Savcenko et al. 2000).
For lossy compression, the most widely used are JPEG (Joint Photographers
Expert Group) compression and wavelett compression. Fractal compression is not
commonly used for medical purposes because of its inferior performance. (Ricke
et al. 1998, Kotter et al. 2003.) The artefacts generated with compression types
vary, and according to reports, influence their suitability for different types of
clinical images. Even though wavelet compression usually enables a higher
compression rate compared to JPEG compression, this is not always true in
clinical settings. (Sung et al. 2002, Schulze et al. 2008.)
Many studies have shown that properly chosen lossy compression has no
effect on diagnostic quality (Lo & Huang 1986, Ishigaki et al. 1990, MacMahon
et al. 1991). In practice, PACS vendors have implemented compression in their
clinical viewer software in order to decrease bandwidth requirements for in-house
networks (Logeswaran 2008).
New recommendations on the use of image compression have been published
by three radiological societies over the last two years 2008–2009:
–
–
Royal College of Radiologists (RCR, UK) “The adoption of lossy data
compression for the purpose of clinical interpretation” (RCR 2008)
German Röntgen Society (DRG, Germany) “Compression of Digital Images
in Radiology - Results of a Consensus Conference” (Loose et al. 2009)
31
–
Canadian Association of Radiologists (CAR, Canada) “Pan-Canadian
Evaluation of Irreversible Compression Ratios (“Lossy” Compression) for
Development of National Guidelines” (Koff et al. 2009)
These recommendations have some similarities, e.g. the use of image
compression is possible without losing relevant clinical informations. There are
slight differences in accepted compression ratios. Based on these papers, users
should be able to implement workflows using “lossy” image compression.
However, that there are still some concerns due to different aspects, e.g.
responsibility, algorithms, post processing. Therefore ESR has initiated a process
to discuss these open issues including well recognized international experts in this
field. The estimated outcome is an official ESR recommendation (ESR 2010).
This activity has been coordinated by the ESR subcommittee for “Information
and Communication”.
2.8
Data safety
Patient information should be kept secret and unmodified, but the data should be
available when needed in patient care. The privacy policy means that only
authorized persons are allowed to see personal health data. (Ruotsalainen 2010.)
These requirements are common in any type of teleradiology.
Telemedicine widens the access to sensitive data and therefore data security
development is an essential part of telemedicine projects. Publicly available
security evaluation methods provide a good starting point for security work. A
systematic approach to data security development facilitates the process, but does
not give answers to all practical questions. (Niinimäki et al. 2001.)
The security and privacy protection of any teleradiology system must be
planned in advance, and the necessary security and privacy enhancing tools
should be selected based on risk analysis and requirements set down by
legislation (Ruotsalainen 2010). There is, however, a trade-off between security
measures and system performance (Engelmann 1999, Zhang 2007).
Wireless security specifically has three goals: (1) restricting wireless access
to authorized users, (2) controlling which devices are allowed access to the host
network, and (3) encrypting wireless data transmission to prevent eavesdropping,
modification or insertion of data with respect to the wireless data stream. Server
and client security (including PCs, laptops, PDAs etc) is a separate, but equally
important, security objective. (Pyrros & Yaghmai 2008).
32
2.9
Work process
As mentioned earlier, the first clinical teleradiology experiments were based on
television technology, which mostly required simultaneous presence of the
participants. A major logistic step forward was the store-and-forward approach,
which simplified operation by eliminating the need for all parties – patients,
providers and other support staff – to be present simultaneously at both sites
(Thrall 2007a).
In terms of systems design, teleradiology can be seen as one application area
of interactive or computer-supported cooperative work (CSCW) systems. Within
systems design, it is quite common to view such systems in terms of workflow,
often accompanied by a chain of tasks view of work (Abbot & Sarin 1994).
These identifiable, usually system use-related tasks make up only part of the
teleradiology service and the time spent on making it work. It is not sufficient to
study only these isolated tasks, however; an investigation of actual, everyday
routine activities is needed in order to understand the contextual details of work
and interaction in ways that support the usability of the system. Even though
technical (Uldal et al. 1997, Glinkowski & Kornacki 2002, Struber & Tichon
2003), clinical (Goh et al. 1997a, Goh et al. 1997b, Kiuru et al. 2002, Stranzinger
et al. 2003, Daucourt et al. 2005) and economic (Bergmo 1996, Halvorsen &
Kristiansen 1996, Johansen & Breivik 2004, Daucourt et al. 2006, Kreutzer et al.
2008, Plathow et al. 2005) aspects of teleradiology have been investigated
intensively, there are not many studies with a work practice-oriented focus
describing real-life teleradiology work between primary and secondary care
(Karasti 1997, Karasti 2001).
2.10 Motivation of teleradiology
2.10.1 Effectiveness of teleradiology
Teleradiology has been seen as being economically feasible in Norway in a
situation where it replaced a visiting radiology service to a remote hospital, the
examinations consisting of plain radiographs (8,000 examinations per year)
(Bergmo 1996).
Another early example from Austria showed that teleradiology of emergency
CT examinations from a regional hospital to a university hospital was
economically feasible compared to patient transportation even with a reasonable
33
low number of examinations (121 examinations over a period of 13 months)
(Stoeger et al. 1997).
Similar benefits have been reported by Goh et al. (Goh et al. 1997a) on the
role of teleradiology in the management of inter-hospital transfer of neurosurgical
patients. They found that for patients referred with teleradiologic images,
unnecessary transfers were reduced by 21%.
In a large prospective series from Aquitaine France, all teleradiology
transmissions in 15 hospitals and over a period of one year were examined. There
were 664 (90%) transmissions that met the inclusion criteria. Of these, 562 (85%)
were for emergency care and 102 (15%) for non-emergency care. In emergency
care, the pathologies most often associated with a remote consultation were
cerebral pathologies (88%) and traumatic spinal pathologies (8%); the proportion
of avoided transfers was 48%. In non-emergency care, the specialties most often
concerned with remote consultations were neurology/neurosurgery (36%),
cardiology and pulmonary diseases (17%) and gastroenterology (14%). Transfer
was avoided for 37% and hospitalization for 12% of the patients. An additional
consultation occurred after remote consultation for 2% of the patients (Daucourt
et al. 2005). A cost-minimization study enabled a comparison of care procedures
following the use of the network with those that would have been implemented
without the network. Annual savings can be estimated at EUR 102,779 for the
Aquitaine area (Daucourt et al. 2006). The results confirm the effectiveness of an
inter-hospital teleradiology network. (Daucourt et al. 2005.)
In a primary care setting, a teleradiology service linking a general practice in
rural Norway with the local hospital in the nearest town was evaluated, and
savings on travelling expenditure were registered for all patients who underwent
elective examinations during the first year of service. Over a four-month period in
2002, it was recorded whether patients undergoing emergency examinations were
taken in at the local general practice or referred to the hospital. The method
employed was a cost-minimization analysis in which the costs of teleradiology
are compared to the costs incurred when patients go to hospital for a radiological
examination. On the basis of data for 3,006 patients, the analysis showed that on
an annual basis the service resulted in savings of NOK 1 million (USD 160,000).
According to the authors, teleradiology is most likely to be cost-effective when
annual patient load and travel costs are high, together with relatively low
investment costs. (Johansen & Breivik 2004.)
In Finland, the clinical effectiveness of primary care teleradiology has been
well demonstrated (Kiuru et al. 2002). In the study, 685 plain film examinations
34
were sent from a primary care centre to a university hospital via an ISDN
connection for a radiological report. The study was conducted in two phases:
during phase 1 (446 cases), general practitioners (GPs) selected the examinations,
and during phase 2 (239 cases), all consecutive examinations were transmitted. In
at least one-third of all cases, teleradiology helped with the diagnosis, although
completely new diagnoses were less common. An effect on treatment was noted
in 15% and on prognosis in 5% of the cases. However, an appropriate
consultation level is required for these positive effects. Adequate accuracy and
patient safety cannot be achieved if the examinations sent for radiological
reporting are preselected by a GP.
In their systematic review of telemedicine articles Roine at al. were able to
show that one the strongest pieces of evidence of the effectiveness of
telemedicine is within teleradiology, especially teleneuroradiology (Roine et al.
2001).
2.10.2 Quality aspects
A proper quality assessment should be included in teleradiology service in order
to assure users that remote interpretation is as accurate and fluent as local image
reading (Wong et al. 2005, Branstetter 2007).
A Tyrolean ‘four-column model of quality management in telemedicine’ was
introduced to ensure a global view of the project and to avoid mistakes. In
teleradiology, a 12-step workflow was developed, describing the medical
responsibilities at each stage. The investigators found that the defined
teleradiology workflow and the technical equipment for data security and data
exchange worked without problems in over 79% of a total of 424 cases. To ensure
continuous quality assurance, the whole teleradiology workflow was ISO
9001:2000 certified. (Soegner et al. 2003b.)
In another study, careful analysis of errors resulted in reduction of the number
of mistakes (mostly minor workflow errors), from 23 errors per month in January
2002 to 9 errors per month in January 2003. The authors concluded that
continuous cross-checking of the workflow and training of the employees
involved guaranteed a better standard of teleradiology. (Soegner et al. 2003a.)
35
2.11 Use of teleradiology
Several factors – including the prevailing shortage of radiologists, the increasing
use of advanced imaging methods, the consolidation of hospitals into regional
delivery systems, and heightened expectations of patients and referring physicians
for timely service – have fostered the increasing use of teleradiology. These
factors have also helped underwrite the creation of new and potentially disruptive
business models for service delivery that can be viewed as threats, opportunities,
or both, but which cannot be ignored. (Thrall 2007a.)
2.11.1 Point to point consultations
Teleradiology has traditionally been used for secondary opinion or for off-hours
emergency consultations (DeCorato et al. 1995, Wilson 1996). It has also been
proposed for educational purposes (Thrall 2007a, Canadian Association of
Radiologists 2008). A rather new aspect in teleradiology is outsourcing the
workload, where a major part of the service is given away from regular staff to an
external expertise centre. In the US, a new term, “nighthawking” has been coined,
because off-hour consultations by external experts are such a common practice.
(Boland 2008.) At the 2007 meeting of the Radiological Society of North America
there were 41 teleradiology companies that provided nighttime coverage, daytime
coverage, or all of the above (Bradley 2008). According to another study, 44% of
all radiology practices in the United States reported using external off-hours
teleradiology services in 2007. These practices included 45% of all U.S.
radiologists. Out-of-practice teleradiology had been used by 15% of practices in
2003, so the amount has tripled. (Lewis 2009.) In the EU area there is service
provider based in Spain that provides local as well as international services (Eklof
et al. 2007).
2.11.2 Regional service concept
Regional access to a joint PACS archive actually means teleradiology workflow,
if the images are interpreted in a different location from the imaging site. This
concept makes it possible to build up a virtual hospital, where even small sites
can enjoy sub-specialist consultations or where sub-specialist expertise can be
used more efficiently without physical boundaries. Primary health care centres
can have access to radiology consultation as if they had this service on their own
36
premises. An additional benefit is access to older images and thus avoidance of
excess radiation exposure. (Harno et al. 2002, Harno 2004, Vogl 2005.) For image
interpretation it is also important to have comparison images from other sites
available; this allows physicians to follow up pathologic changes over time,
which results in more accurate diagnosis.
One major regional PACS installation in Finland is HUSpacs, consisting of
the images of 21 hospitals and related primary health care centres (Pohjonen et al.
2004). In Austria, the Insbruck region has built a comprehensive telemedicine
installation connecting the university clinic with a district hospital (Soegner et al.
2003b). Both of these examples implement remote interpretation of images.
Integrating primary health care centres to secondary care via information
systems can create a virtual electronic health record and change service models
(Harno et al. 2002). When associated with viewing of patient data through the
link directory, interactive eConsultations enable supervised care leading to the
reduction of outpatient visits and more timely appointments. In the HUSpacs
information system the link directory is an interface containing links pointing to
the actual patient data located in remote information systems. The original data
including images can be viewed with a web browser, but data can be accessed
only with the patient's informed consent. This means that the citizen has an active
role in deciding on the use of his medical information (Harno 2004). In this
manner the link directory system has implemented the European data protection
directive (Directive 95/46/EC 1995).
An interesting idea has been proposed by Wootton, stating that one advantage
of teleradiology would be omitting the need to maintain specialist staff in
hospitals where the volume of radiology may not justify it (Wootton 2001).
2.11.3 Mobile teleradiology
Wireless transfer of radiology images to a portable computer was reported early
in emergency medicine using analogue cellphone technology (Yamamoto 1995).
With the advance of digital cellular phones and worldwide digital networks image
transmission has been extended to major catastrophe sites and for purposes such
as delivering information needed in post mortem recognition of bodies (Salo et al.
2007).
Wireless technology is identical to conventional teleradiology, with the
obvious difference of using a radiofrequency wireless network for the digital
communication of radiographic images. There are four major disadvantages with
37
wireless technologies: reliability, cost, security and speed. The obvious major
advantage of such technology is the ability to view images virtually anywhere,
from a hospital patient room to the quagmire of the battlefield. In addition, the
costs of wireless networks and their speed have become insignificant issues:
many would in fact argue that deploying a wireless network saves costs, as it does
not require the expense of cabling. (Pyrros & Yaghmai 2008, Thrall 2007a, Thrall
2007b.)
Wireless devices have been utilized with wireless broadband technology
within the hospital environment in ward rounds. In a Finnish study a mobile
Tablet-PC/Webpad- based system with WLAN (Wireless Local Area Network)
connectivity was used to access both textual and image data in the wards. The
data access was fast and comparable with terminals connected to the ordinary
hospital network. The main limitation of WLAN was that outside the hospital
campus area it was only available at so-called service points, “hot spots”. WLANbased image review was thus not considered suitable for health professionals who
are on duty and have to be able to connect to the hospital at any time. (Pagani et
al. 2003.)
A new type of equipment class entered the market when pocket computers
emerged, and to demonstrate the feasibility of wireless pocket teleradiology, brain
CT scan images of five neurosurgical emergency cases were received on a pocket
computer via a wireless modem link (Yamamoto & Williams 2000).
2.11.4 International teleradiology consultations
International teleradiology was first developed in a military setting. The first
published article describes how an US army team lead by Lt. Col. Fred Goeringer,
MSC, deployed a CT scanner to a transportable hospital in the Saudi Arabian
desert during the first Gulf War in 1991. The images were transmitted via satellite
and telephone links to Brooke Army Medical Center in San Antonio, Texas, for
specialist radiology consultations. Another objective was to validate the concept
of distant interpretation of images obtained on the battlefield. According to the
report, the scan quality was excellent and the scans proved clinically important in
patient management. (Cawthon et al. 1991.) This pilot showed great promise for
both combat and civilian teleradiology and led to further development (Mun et al.
1998).
The Internet opened up new possibilities for international consultation
possibilities. The Nordic countries were among the forerunners in utilizing
38
Internet connections (Ahonen 2008). The new route was at that time tested for
medical purposes. Data safety was a concern at the beginning, but patient data
anonymization, secured network connections like VPN (virtual private network)
and SLL (secure socket layer) technology or data encryption were gradually
adopted in public network connections and international connections as well.
(Wunderbaldinger et al. 1999, Seibel et al. 2000, Niinimäki et al. 2001, Alaoui et
al. 2003, Bergh et al. 2004.)
Today, technical aspects do not necessarily restrict international image
transfer. Images are stored in DICOM format and can thus be transferred with
DICOM command to capable destinations. What is more complicated is the
transfer of equally important RIS information and EPR information. This is
related both to lack of commonly used standards in this area as well as possible
language issues. (Arenson et al. 2000, Siegel & Reiner 2002, ESR 2004.)
2.12 Concept of eHealth
Utilization of ICT (information and communication technology) in health care has
moved from individual projects and services to a more comprehensive model.
Instead of telemedicine, terms like telehealth, eHealth, on-line health and most
recently connected health (Microsoft Corporation 2009) have emerged.
eHealth is an umbrella term that gathers together ICT usage in health care
(World Health Organization 2010). It includes major infrastructure services and at
the other end also services targeted to individual citizens. According to the EU
eEurope action plan “An information society for all” eHealth could also seen as a
derivative of eServices, in line with similar terms like eCommerce or
eGovernance (COM/2002/0263 final). The main political goal is to deliver more
accessible and better services to citizens.
eHealth has been strongly emphasized by the European Commission since
2003, when the first eHealth ministerial meeting was held and the first Ministerial
Declaration (2003) on the topic was given. Since then, the European Commission
has encouraged member states to include eHealth in their national health policies.
The WHO has also created its own world wide eHealth strategy (World Health
Organization 2010).
39
2.12.1 National initiatives for electronic patient documents
Finland is a good example of a country that has been an early adopter of eHealth
policies. The information management infrastructure of Finnish health care on a
national level will be based on an internationally unique centralized electronic
archive. The operative use of EPRs will take place on a regional or local level.
(Hämäläinen et al. 2009, Winblad et al. 2010.)
The core of the national Finnish health ICT infrastructure will reside in the
national digital archive for patient documents. It is since 2007 based on
legislation (L 159/2007) and its implementation will be mandatory for all health
care providers in the public sector. For private providers of physician services the
implementation will be mandatory for those using electronic documentation of
patient data.
The national architecture consists of local EPRs using a common data
structure and technical standards, the national eArchive in which all EPRs are
made available online subject to patients’ consent (L 159/2007 2007). In addition,
the archive will include a national ePrescription database based on act on
electronic prescription (L 61/2007 2007), and an eView for citizens, enabling
them to access their own patient data and log data (L 159/2007 2007).
There are several challenges to be overcome with the national archiving
system. It is a technologically complex system that has to be implemented
alongside the everyday service routines of health care. In order to work on a
nationwide level, interoperability of systems is crucial. In addition, the volumes
of information transfer, for instance in radiology, may be very large and overload
the data networks. The system requires that health care employees use an
electronic signature and learn new ways to work, such as documenting patient
information in a structured manner. (Winblad et al. 2010.)
2.12.2 EU cross border telemedicine initiatives
Since the beginning of 2000s, the European Commission has become interested in
the possibilities of cross-border telemedicine. The topic has been discussed in the
EU-funded projects Baltic eHealth and R-Bay (Ross et al. 2010). In the Baltic
eHealth project teleradiology was utilized between the Baltic states and Denmark.
The image interpretation results were dictated in the native languages of the
radiologists and translated into Danish with a computer-based structured form.
Legal issues concerning cross-border telemedicine were also investigated in the
40
project. In the R-Bay project a more general concept of an international
teleradiology marketplace was studied.
More recently, the EU has initiated the epSOS project (Smart Open Services
for European Patients), where interoperability issues are investigated between the
electronic patient record systems of various European countries in a more general
setting of cross-border telemedicine (epSOS 2008). The EU Commission has
promoted cross-border telemedicine and eHealth in ministerial meetings, given
out various statements: a Commission Recommendation on cross-border
interoperability of electronic health record systems (C(2008)3282), a Commission
Communication on telemedicine for the benefit of patients, healthcare systems
and society (COM/2008/0689 final) and a Ministerial declaration (2010) on
European co-operation on eHealth. The EU parliament has been also discussing
incorporating definitions of cross-border telemedicine into the directives on the
mobility of services (Commission Proposal for a directive 2008/0142) which will
be voted in January 2011.
The European Society of Radiology (ESR) has published two guideline
“white papers” concerning teleradiology (ESR 2004, ESR 2006). In these papers,
teleradiology is seen as a feasible opportunity, but ESR stresses the quality
aspects. In relation to directives discussing cross-border telemedicine, ESR
reminds that teleradiology is a medical act and should be treated accordingly.
2.12.3 Teleradiology as a part of eHealth services
In the future health care environment teleradiology has a strong role as one of the
services given (Shieh et al. 2008). It is a means of delivering care, but not a
medical discipline in itself. One key issue is the well-established integration to
other health information systems, especially RIS (Roberson & Shieh 1998). From
the point of view of users, usability and reliable functionality are key issues
(Shieh & Roberson 1999).
Health care services are becoming more ubiquitous (Kyriacou et al. 2009).
Experts need to be reachable anytime and anywhere, and they require the same
amount of information they rely on while working within hospitals. For
teleradiology, the technological possibilities with more capable handheld devices
and even faster wireless networks are no longer an obstacle. Mobile health care
systems (mHealth) have been said to be the next major step forward in
telemedicine. (Voskarides et al. 2002, Herscovici et al. 2007, Waegemann 2010.)
41
Virtual hospital is already a existing possibility (Jones 2000, Graschew et al.
2006). Various institutions can be linked together and workflows can be
synchronized (Bradley 2008). This requires hard work, however, as integration
standards are not well developed or not adopted to a satisfactory degree in other
HIS compared to medical imaging systems. For teleradiology purposes, the
existing infrastructure is for the most part sufficient if RIS and HIS information
can be transmitted. A common regional information system could help solve
many of the problems that exist today. (Harno et al. 2002, Harno 2004.)
Outsourcing of work is a solution to distribute the burden of excess workload
and perhaps a tool to connect sub-specialist radiologists with their own patients
(Bradley 2008). A new structure for the radiology department is also needed. The
risks are also obvious – how to cope with quality issues and keep up interest also
in the boring, bulk-type interpretation work?
42
3
Purpose of the study
The purpose of this study was to evaluate the use and implementation of
teleradiology, namely:
1.
2.
3.
4.
5.
6.
whether a low-end technology teleradiology system could combine
acceptable image quality with reasonable costs and serve primary health
centres and local hospitals for image consultation
whether there will be noticeable changes in work processes and what are the
most important work practice issues when two different institutions start to
work together,
whether international teleconsultations using data networks could link
together different institutions in a feasible manner,
whether new ubiquitous communication tools, such as mobile data
communication, are suitable for radiological purposes,
whether smartphones could be used for image interpretations, and finally,
to chart the usage status of teleradiology and digital radiology in the
electronic health care (eHealth) domain in Finland in general.
43
44
4
Subjects and methods
4.1
Low-end technology teleradiology
The hardware consisted of a standard PC computer with an Intel (Santa Clara,
USA) processor. The images were scanned using a 300 dots per inch (DPI) flatbed charged coupled device (CCD) image scanner (model XRS CX3 by X-Ray
Scanner Corporation, Torrance, USA) with a 21 × 35 cm scanning area, giving a
maximum of a 2478 × 4130 pixel matrix. In practice the image digitization matrix
sizes varied from 512 × 512 to 2048 × 2048 pixels depending on the selected
resolution and image size. Each pixel had a 256-step (8 bits) grey scale. Large
images (e.g. 35 cm × 35 cm films) were scanned in two parts and connected
together. A commercial image-processing program was used for scanning and
viewing (PhotoStyler by Aldus Corporation, Seattle, USA). The computer screen
was 47 cm in diameter. Its resolution was 1024 × 768 pixels, but the image
zooming and scrolling functions in the viewing program made it possible to
interpret larger digitized images.
The image data were transmitted via a dial-up digital 64 kilobits per second
(kbit/s) one-channel ISDN telephone line with the help of a communication
program (TeleImage by Telecom Finland). The procedure of sending the images
consisted of the following steps: (1) selecting the images, (2) prescanning and
setting up parameters for the first image, (3) scanning, (4) saving the files, (5)
making a connection, (6) sending the images. Image receiving was automatic.
Both the on-line sending time and the total image transmission time were
recorded.
The PC-based teleradiology system was tested in three different system
configurations (phases). The software interface and the use of compression
differed in these three phases. In the first and second phases, all the programs had
to be used separately and the scanning parameters were adjusted manually. No
common user interface was used. In the first and second phases, all the images
were sent uncompressed. Before the actual clinical cases, a small pilot series of
10 images was made to determine appropriate settings for image digitalization.
In the third phase, the effect of data compression and a new easier graphical
user interface (programmed with Microsoft Visual Basic) on the total transfer
time was tested. All the programs operated in a Microsoft Windows environment.
No more than five buttons were available at each screen. Presets for the scanning
45
parameters were used for different images. These presets included a possibility to
decrease excessive contrast in chest and bone images. Image resolution for chest
and bone images was now set to the same level as in the commercial image plate
system Fuji AC-1 (Fuji Corporation, Tokyo, Japan). In this series, images were
sent using lossy DCT (discrete cosine transform) image compression with
approximately 1:10 compression results (Joint Photographer Experts Group,
JPEG compression). (In literature, DCT compression methods with slight
compression between 1:10 and 1: 25 depending on the quality of the original have
given acceptable results with no statistical difference in diagnostic quality (Lo &
Huang 1986, Ishigaki et al. 1990, MacMahon et al. 1991). JPEG compression has
been proposed for use in PACS environments (Kajiwara 1992). The requests and
reports were written with the Windows Write program (Microsoft Corporation,
Seattle, USA) in a separate program window on the same terminal.
A total of 254 films were sent, all to a university hospital. In the first phase 48
uncompressed images were sent from a rural health centre, and in the second
phase 126 sets of uncompressed images were sent from a central hospital. In the
third phase, 80 compressed images were sent from a regional hospital.
The selection of patients was made so as to simulate as accurately as possible
real teleconsultation needs when radiological expertise is not locally available. At
the health centre the images were scanned and sent by a computer operator, while
in the central hospital and the regional hospital this was done by x-ray technicians.
At the university hospital, the images were interpreted by two staff
radiologists on a computer screen. They first scored the images as acceptable or
unacceptable in the technical respect. After that, a consensus diagnosis was made
from the technically acceptable images. A report was given and returned to the
sender via telefax in phases 1 and 2 and as a computer file in phase 3. The same
radiologists inspected the original images two weeks later and again made a
consensus diagnosis. The diagnoses were compared for possible differences.
4.2
Work practise analysis
The study
The work practice study consisting of fieldwork (from October of 1995 to January
1996) and workshops (March and May of 1996) was carried out in connection
with the implementation and clinical use of the new teleradiology system, which
46
was designed to answer many shortcomings found in the first paper. Especially a
new 12 bit gray scale full film area CCD-scanner (Pinja by Finnelpro, Tampere,
Finland), a new archiver and communication software (Medilink by Acta Systems,
Oulu, Finland) and a new networked teleradiology review workstation with a
high-resolution 1600 x 1280 pixel screen and software developed for the purpose
(Pinjaview by Finnelpro, Tampere, Finland) with an adjacent electronic text
messaging service for referrals and reports were integrated together. The database
combining images and text made it possible to follow the status of consultation
tasks. For an overview of the teleradiology system configuration, see figure 2.
Fig. 2. Teleradiology set-up between Kuusamo primary care health centre and Oulu
University hospital. Technical details are explained in the original paper (Paper II,
published by permission of Elsevier).
The common purpose was to achieve a high usability with an iterative
development process after the initial launch of the system. The experimental stage
lasted from October 1995 to April 1997. During this period, a total of 375 image
packages consisting of several images were transferred. Parallel to the fieldwork,
user questionaires were collected of 108 consecutive cases, with questions asking
the case distribution and the image processing tools used by the physicians. In the
study the reseachers from the Department of Information Processing Science took
47
care of conducting the fieldwork and workshops while the researchers from the
Department of Diagnostic Radiology took care of the development and use of the
teleradiology system itself, the user questionaires, and expert participation at the
workshops. Both teams then contributed to the multidisciplinary presentation of
the results with an emphasis on image interpretation.
The fieldwork
Interviews with design team members and participants on the use of the
teleradiology system were conducted during the fieldwork (Karasti 1997) with
total of 12 interviews. Emphasis was, however, on studying the actually occurring
clinical practice of teleradiology in everyday settings in both locations
(approximately 15 working days) by observation, contextual interviews and
videotaping. A total of 21 system use-related instances of work were recorded (11
image interpretation sessions, 4 instances of typing out reports and sending them,
6 instances of scanning and sending images). Stimulated recall interviews
(Engeström 1996) were carried out with the radiologists whose interpretation
work had been recorded (7 patient cases). The interviewees and researchers
watched the tapes together, questioning and commenting on the events recorded.
Analysis of work practice started already during the fieldwork as the fieldworkers’
interpretations and formulations of the phenomena were continuously challenged
by new observations. The stimulated recall interviews also served as collaborative
analyses. After the fieldwork more focused and detailed video analyses were
conducted with special attention on the unfolding of work: interaction and use of
materials, skills and knowledge employed in work.
The workshops
Based on the fieldwork and the analyses of work two workshops were organized
(Karasti 1997). The communities of work practice, design and research were
brought together to collaboratively evaluate and redesign the system so as to
support the established and contingent practices through which the work is
accomplished and to address issues relevant to developing the teleradiology work
practice. Participation of all occupational groups involved in the teleradiology
practice was required. A video collage of actual work situations was edited to
present the entire teleradiology work practice in parallel to corresponding
traditional ways of working. The video collage served as a shared object of
48
interest and helped provide a basis for the cooperative analysis of actual work
practice. The participants were able to compare practices and share their
experiences. They built a common understanding of the teleradiology work
practice. System usability was evaluated based on cooperatively produced
emergent practical criteria. Moving on from evaluation to envisioning future use
situations they started to raise informed issues relevant to both system redesign
and development of work procedures.
4.3
Internet teleradiology
An experimental consultation system was tested between Oulu University Central
Hospital in Finland, University Hospital of Reykjavik in Iceland and University
Hospital of Tromsø in Norway. The hospitals provided a gateway access (firewall
policy) to the NORDUnet network and workstations for image viewing and
interpretation. Access to digitized images occurred either by network connection
to image sources or by film digitization with a CCD scanner. Digitized images
were converted to common TIFF (tagged image file format) or JIF (JPEG
interchange format) file formats and sent using Internet FTP (file transfer protocol)
protocol. Technical details of the hardware are summarized in Table 2.
Table 2. Technical details of the hardware used in multicentre Internet teleradiology
(Paper III, published by permission of Springer).
Hardware
Reykjavik
Digitizer
CCD
CCD
CCD
CCD
Pixel size
85 µm
170 µm
85 µn
85 µm
Grey scale
8 bits
12 bits2
8 bits
8 bits
3
Gateway
Unix/HP
Viewing station
PC 486
Display pixels
1280x1024
1
Unix/Sun
4
Tromsø 1
Tromsø 21
Oulu
components
Unix/HP/Sun
Unix/HP
PC 486
Unix/HP/Sun
Unix/HP
1280x1024
1280x1024
1280x865
Tromsø used two different hardware constellations, 2 only for digitalization, image display grey scale was
always 8 bits. 3 HP is a trade mark of Hewlett-Packard. 4 Sun is a trade mark of Sun Microsystems.
In the first study, 131 randomly selected neuroradiological CT and MRI images
plus skeletal x-rays were sent between Oulu and Reykjavik. Different
compression methods (lossless LZW (Lempel–Ziv–Welch) with compression up
to 1:2.4 and lossy JPEG compression up to 1:10) and image resolutions were
49
tested and transmission times recorded. The images were compared with originals
for possible differences in quality or diagnosis.
In the second study MRI studies of pituitary glands were sent between each
institution. Laser-printed images were digitized and compressed according to the
results of a previous study with lossy JPEG-compression with quality factor 85,
giving approximately 1:10 compression. Twenty pituitary cases were sent from
Iceland both to Norway and Finland. In the same manner, 20 cases were sent from
Finland to Iceland and Norway. These four sets made a total of 80 cases. The
clinical information given was always the same: suspected enlargement of sellar
contents or suspicion of microadenoma. In every institution three
neuroradiologists interpreted the digital images on the screen and indicated each
abnormality according to a 5-point confidence scale: 1= definitely not present,
2=probably not present, 3=cannot be decided, 4=probably present, 5=definitely
present. The interpreters used grey-scale windowing and zooming functions on
the workstation. The original analogue radiographs were interpreted in the same
manner two weeks after the workstation session. The actual diagnosis was
determined by consensus of two neuroradiologists in the sending site using all the
patient information available. Receiver operating characteristic (ROC) curves
were produced and the area below them and statistics calculated by using methods
described in radiological literature (Hanley & McNeil 1982, Hanley & McNeil
1983).
In connection with this study 12 clinical consultation cases were sent from
Iceland to Finland, recording the time of sending, viewing and reporting. These
cases included both images and the request for examination. For data safety
reasons, patient identification data were removed from all the material sent.
4.4
Mobile PC teleradiology
Portable terminal
The neuroradiologist was supplied with a portable terminal capable of receiving
and viewing images. The terminal was constructed from a notebook computer
(Contura 430cx, Compaq Computer Corp., USA) equipped with an active matrix
display of 640 × 480 pixel resolution. The display was capable of showing 256
colours. The computer weighed 1.7 kg, measured 23 × 30 cm and cost about EUR
50
3150. The computer had a 16 MByte random access memory and an 800 MByte
hard disk.
MS Windows (Microsoft Corp, Seattle, USA) was used as the operating
system. Images were viewed with a shareware program (Polyview, Polybytes,
Cedar Rapids, USA).
The notebook computer was equipped with a PCMCIA digital cellular data
card (Nokia Mobile Phones, Salo, Finland). This was used to interface the
computer to a GSM telephone (Nokia 2110i, Nokia Mobile Phones, Salo,
Finland). When the neuroradiologist was not in the hospital, the data connection
to the hospital was established through the GSM network. A commercial GSM
data service (Telecom Finland, Helsinki, Finland) was used for the wireless
connection. The nominal data transmission rate was 9.6 kbit/s.
The telecommunication software used was the Microsoft remote access
service of Windows 95. The remote access service included PPP (point-to-point
protocol) client software that could be used to connect to a PPP server at the
hospital over a modem line. Microsoft’s implementation of the TCP/IP was used
over the PPP connection. PPP is the certified Internet standard protocol that
extends the LAN protocols to function over a modem line. When the TCP/IP
connection was established, a data transmission connection was formed and the
images were transferred using an FTP program (WS-FTP, Ipswitch Inc, Lexington,
USA).
Dial-up server
To provide a dial-in connection to the LAN of the Department of Radiology, a
PPP server was set up. The server accepted incoming modem calls and, after user
authentication, provided a connection to the LAN. When the connection was
active the server routed network packets between the modem line and the LAN.
In the present study, the server was used to provide a TCP/IP connection between
the LAN and the portable terminal.
Initially the PPP server was based on a Unix workstation (Indigo, Silicon
Graphics, Mountain View, USA). Subsequently, it was changed to a standard Intel
Pentium (Santa Clara, USA) personal computer. The computer used Linux, a
freely distributable implementation of Unix, as the operating system.
51
Imaging device interface
The patients were imaged with a CT scanner (GE HiSpeed Advantage or GE
Sytec 3000, GE, Milwaukee, USA). The images were routinely transferred to a
visualization workstation (SUN Microsystems, Mountain View, USA) via the
LAN.
The visualization workstation used a diagnostic visualization program
(Advantage Windows, GEMS, Buc, France). The visualization workstation had a
display with 8 bit/pixel colour depth, which was able to show 256 colours
simultaneously. The contrast window and the brightness level of the images were
set to make the images suitable for diagnosing from the monitor. For the technical
set-up, see figure 3.
Fig. 3. The technical configuration of the wireless image consultation chain. The
portable terminal connects to a private dial-up server for a secure image consultation
(Paper IV, published by permission of RSM press).
After manipulation, the images were captured from the screen using public
domain xv software with a special script. This was performed by an X-ray
technician who had detailed instructions to manipulate the images to look the
same as if printed on film. The capturing took on average 7 min per patient. The
colour depth used was the full dynamic range of the display, i.e. 8 bits/pixel. The
images were captured at the original 512 × 512 pixel resolution. The captured
image size was 256 kBytes in size. All the captured images from the visualization
workstation were stored in a network directory that was physically mounted on
the dial-up server.
52
To reduce the bandwidth required for transmission, the images were
compressed with a JPEG algorithm and stored in 8 bits/pixel greyscale format.
The JPEG quality factor used was 75%, resulting in an approximate compression
ratio of 8:1. This yielded an average image size of 40 kBytes. The images were
then automatically transferred in patient folders to the dial-in server.
Patients and interpretation
The material consisted of 68 consecutive neuroradiological emergency patients
(36 males and 32 females). The mean age was 59 years, range 1–90. There were
63 head, 1 lumbar spine, 2 sinus, 1 orbital and 1 neck CT examinations.
Two series of scans were examined. In the first series, a neuroradiologist
interpreted the CT scans of 47 patients on a portable computer during working
hours. Later, the same neuroradiologist reviewed the images on film. In the first
series, all the CT slices obtained in each examination were transmitted. The
experience was used to define the second part of the study.
In the second series, the images of 21 patients were sent by a junior
radiologist for a neuroradiologist consultation after normal working hours. Three
senior neuroradiologists gave their advice in turn. These results were also
compared to the film interpretation the next morning. In the second series, the
junior radiologist either sent all slices or only those slices covering the area
requiring consultation. In the re-evaluation, the images of all patients were
viewed in the manner used by the radiologists to interpret CT-images in daily
work. A written report was made for both transmitted and comparison images.
The images of patients were transferred to the portable terminal by GSM. The
image transfer times (both FTP connection time and total time) were recorded.
After receiving the images, the radiologists evaluated them for diagnostic quality,
scoring them as: 1=suitable for final diagnosis, 2=suitable for preliminary
diagnosis only or, 3=not suitable for diagnosis. The reasons for inadequacy were
recorded. The neuroradiologist also evaluated each image consultation on a fivepoint scale indicating whether the image consultation was beneficial compared to
an ordinary telephone discussion. The scale was: 1= no need for consultation,
2=no benefits over a telephone conversation, 3=minor benefit, 4=beneficial for
diagnosis, 5=gave essential information. The neuroradiologst also decided and
recorded whether a hospital visit would have been necessary without the image
transfer.
53
4.5
Smartphone teleradiology
4.5.1 Feasibility study
PDA terminal
The PDA terminal device for image reception and viewing was a Nokia 9000
Communicator (Nokia Ltd, Helsinki, Finland), which was a combined digital
phone and messaging device with short message service (SMS), telefax and even
Internet/intranet capability. It could be called an intelligent phone (smartphone) or
personal digital assistant with GSM phone capabilities. It weighted 397g and its
dimensions were 173 × 64 × 38 mm. The LCD (Liquid Crystal Display) display
area was capable of showing graphics of 600 × 200 pixels with 8 grey levels, and
the contrast was adjustable. Larger images could be viewed using zooming and
scrolling functions. It had 8 megabytes (MB) total memory, 4 MB for operating
system and applications, 2 MB for program execution and 2 MB for user data
storage. The cost of the terminal device was 1,000 Euros. As an extra capability,
the phone was equipped with Celesta MDO Mobile Data Organiser (CCC Mobile
Ltd, Oulunsalo, Finland) file transfer software.
Hospital teleradiology server and image acquisition
To provide a dial-in connection to the LAN of the Department of Diagnostic
Radiology, a private PPP server using a Microsoft remote access service (RAS) of
Windows NT (Microsoft Corp., Seattle, USA) was set up. PAP (Password
Authentication Protocol) was used as an authentication mechanism for PPP
connection. After user authentication a TCP/IP connection between the PDA
terminal and teleradiology server of the hospital was established using
commercial GSM data service. Internet standard protocol FTP was used for
transferring the images from the teleradiology server to the PDA terminal.
The patients were imaged with a CT scanner (CT HiSpeed Advantage or CT
Sytec 3000, GE, Milwaukee, USA) and the image capture arrangement was the
same as reported in the previous work on mobile PC teleradiology and described
in the previous chapter.
54
Patients and interpretation
A junior radiologist at the hospital selected either all the CT slices or slices
containing the area requiring consultation to be stored in the teleradiology server.
After notification of an emergency case, a senior neuroradiologist at home made a
data call, logged into the server and downloaded and viewed each of the 21
patient cases. Twenty of these were head scans and one was a sinus scan. There
were 12 female and 9 male patients, their mean age being 62 years (range 1–87).
Image transmission, file handling and image interpretation times were
recorded as well as any technical remarks. The neuroradiologist rated the images
for image quality; the scoring was as follows: 1. suitable for final diagnosis; 2.
suitable for preliminary diagnosis only, or 3. not suitable for diagnosis. The
reasons for inadequacy were recorded. After that the neuroradiologist gave a
written report. These reports were compared to the original report given at the
hospital and to a reference reading from the original films the following day. The
neuroradiologist also scored each image consultation on whether it was beneficial
compared to a telephone discussion. The scale was: 1. no need for consultation; 2.
no benefits over a telephone conversation; 3. minor benefit; 4. beneficial for
diagnosis; 5. gave essential information. The neuroradiologist also recorded
whether a hospital visit would have been necessary without the image transfer.
4.5.2 Clinical study
MOMEDA
According to the concept, a Mobile Medical Data server was established in the
hospital intranet. In the case of consultation, the server received the DICOM
images and sent them together with relevant narratives retrieved from the hospital
EPR system. After an automatic SMS initiation, data connection was established
with a secure call-back method and connections were authenticated with a double
security verification (both at the PPP server and at the communication software).
The terminal device was a Nokia 9110 communicator device (Nokia Ltd, Helsinki,
Finland) which was smaller (158 × 56 × 27 millimetres) and more lightweight
(253 grams) than the original model, yet having still monochromatic display with
640 × 200 pixels and data transfer with GSM data technology (PDAdb.net 2007b).
The developed client image viewer software (Celesta Ltd, Oulu Finland), was a
light-weight version of diagnostic image workstation viewer software, and was
55
capable of full diagnostic manipulation of data. Additional information requests
could be made from the hospital EPR system using a WWW-browser client over a
secure connection. Finally, a consultation phone call could be made to the hospital
with an embedded hands-free phone while reading the images. For the mobile
terminal functions, see figure 4.
Secure Mobile Terminal Access after Local User Authentication
SMS-Receiver/
Listener
Secure Call-back with Authenticated
Server Access and Image Transfer
Radiology Workflow Functions
RIS Worklist /
Patient Information
Referral Text Display
Image Overview/
Thumbnail Display
Error
Recovery
EPR Functions
WWW-Browser/
EPR Query
Image and Text
Unpackager
Communication
Hands-free
Phone
EPR Display
EPR Text Input
Telefax
Full Image Display
Image Processing/
Window/Level, Zoom,
Scroll, Flip, Turn
Basic Office Tools:
Notetaker, Spreadsheet,
Calender, Calculator, Clock
Fig. 4. The radiology workflow and security oriented software components realized in
the integrated mobile image and electronic patient record terminal.
PROMODAS
The Professional Mobile Data Systems project developed the ideas further to 2.5
generation wireless networks and platforms. GPRS technology with IP-protocol
facilitated the fast development of the system because the amount of devicespecific programming decreased. Improved image manipulation functions were
developed for the mobile client software. This first Microsoft Pocket-PC platform
smartphone device O2 XDA (HTC Corporation, Taiwan) was even more
lightweight with 201 grams, yet the processor was more powerful (PDAdb.net
2005). The colour display (240 × 320 pixels, 4096 colours) in this combined PDA
and GPRS mobile phone was larger in vertical direction and capable of showing
more grey levels. The security of the data transfer was also improved, and VPN
tunnelling with strong encryption was utilized. The system architecture is shown
in figure 5.
56
Fig. 5. Schematic architecture of the PROMODAS system (Paper VI, published by
permission of Elsevier).
Evaluation
The clinical feasibility of the MOMEDA and PROMODAS systems was tested in
two different evaluations with real CT and MRI on-duty scans sent to the mobile
terminals. In the first clinical evaluation, 115 CT and MRI scan series were read
with the MOMEDA terminal. In the second evaluation 150 CT and MRI scan
series were read with the PROMODAS terminal. Before the evaluation phase a
short educational pilot was conducted. The reading radiologists, neuroradiologists
and neurosurgeons also had the full examination request coming from the EPR
available at the mobile terminal and were able to use image processing tools at
each of the mobile terminals. Detailed reports were made of each examination,
and after a time interval compared to reports made using the full-size
workstations at the department of radiology. In addition to the results of image
interpretation also the amount of time needed for image transmission and
reviewing the cases was recorded.
4.6
Integration of teleradiology as a part of eHealth services
The structured web-based questionnaire of eHealth usage was distributed by email to all public health service providers or hospital districts and health care
centres, and to a sampling of private health care providers. The survey was
conducted for the first time by FinnTelemedicum in 2003 (Kiviaho et al. 2004)
and repeated in 2005. In this study, data from the year 2005 are presented with
comparison to data from the year 2003 where appropriate. The questionnaire
57
consisted of: the identification of the responding organisation and the respondent;
questions about the adaptation of EPR systems; systems or applications used to
transfer/exchange patient information between organizations during care
processes and the standards in use for the migration of patient information;
methods of authentication, identification, and informed consent of patients; the
usage of different eEducation systems for staff education; the types of human and
material resources needed; systems supporting quality control and service
delivery; and the adaptation of different eServices for patients.
The total number of questions was 97. Most of them also included further
questions on how old the system or application concerned was and the intensity of
use. The questions for hospitals, health care centres and private health care
providers differed to some extent, depending on the nature of the services they
provided.
The intensity of use told about the amount (%) of the action or function being
carried out by electronic means. For example, if a service provider used EPR for
the documentation of patient data in half of the cases and a paper-based record for
others, the intensity of use of the EPR was 50%. Several of the questions in the
year 2005 survey were the same as the questions in the FinnTelemedicum survey
conducted in late 2003, using the same web-based data collection methods.
The questionnaire was emailed between October and November 2005 to all
public service providers, i.e. to 21 hospital districts and 251 health care centres.
The questionnaire was also emailed to a sample of 65 private health care service
providers including 30 of the largest service providers, and 35 who had responded
to the 2003 survey. Additional information was obtained by telephone interviews
from those health care sites where not all information in the returned
questionnaires was complete. Also PACS vendors were interviewed for their
reference sites in primary care. A full report with a detailed description of the
method has been published in Finnish (Winblad et al. 2006) and an English
version with edited information has been published by Hämäläinen et al (2007).
58
5
Results
5.1
Low-end technology teleradiology
Time factor
The average total image transfer procedure time in phase one (from the health
centre) was 15 min 50 sec (range 15 min to 18 min 20 sec) for an uncompressed
single chest x-ray image (average size 3897 bytes). The longest single task in the
transmission process was the on-line sending of image (average 10 min 50 sec),
followed by scanning (64 sec, range 55–74 sec) and saving the images on a hard
disk (57 sec, range 53 to 83 sec). The average throughput of the digital line was
60 kbit/s (range 56 to 61 kbit/s) per second.
The average total image transfer procedure time for a CT film (4 to 6 images
on each film) with an average size of 840 kbytes in phase two (from the central
hospital) was 6 min 20 sec (range 5 min 10 sec to 7 min 20 sec) per
uncompressed film. The longest single step was sending the film (2 min 20 sec),
the next longest step was scanning (35 sec, range 23–42 sec), followed by saving
the films on a hard disk (26 sec, range 19 to 35 sec).
The average total image transfer procedure time for a 1:10 compressed chest
x-ray film in phase three (from the regional hospital) was 5 min for a single view
(36–49% of the time for uncompressed images). Of this, only 30 sec on average
was on-line time (5–9% of that for uncompressed images). The average time
required for the preparatory steps preceding the scanning had decreased from 3
min to 2 min 30 sec.
Technical quality
Of the 48 uncompressed films transmitted in phase one (from the health centre),
two chest x-rays and five bone images were considered technically unacceptable.
This was due to faulty scanner settings; one chest x-ray had an excessively small
scanning area and the other was initially digitized too light. Two thoracic and
three cervical spine images were scanned with excessive contrast settings, with
details lost in both light and dark areas.
All the uncompressed transmitted images in phase two (from the central
hospital) were considered technically high-quality.
59
Of the 80 compressed films sent in phase three (from the regional hospital),
the only low-quality film was an image of the thoracic spine, which was digitized
with excessive contrast settings, with loss of detail in the highlight parts as a
consequence.
Diagnostic ability
Diagnostic agreement between the transmitted and original images was
determined on all of the technically acceptable chest (n=8) and bone (n=33)
images transmitted uncompressed in phase one (from the health centre).
A lesion was missed in two cases of the 126 image sets (2%) transmitted
uncompressed in phase two (from the central hospital). Both cases were brain CT
scans (n=55): The first was a small infarction in the cerebral pons (diameter under
5mm), while the second was a thickening of the right nervus opticus (difference
of 5 mm compared to the other side). All the 38 body CT sets as well as all the 25
angiography film sets, 4 mammographies and 4 ultrasound images were correctly
interpreted from the transmitted images.
A discrepant finding was made in four (5%) out of 79 image sets
satisfactorily transmitted in compressed form in phase three (from the regional
hospital). All of them were mammography images (n=40). After interpreting the
original images, an enlargement mammography was considered necessary in two
cases, while in two cases no further examinations were considered necessary even
though an enlargement mammography was suggested after reading the
transmitted images. All the twenty chest images and all the nineteen bone images
were interpreted correctly from the transmissions.
Total diagnostic agreement between the transmitted images and the original
films was 98% in the technically acceptable image transmissions.
5.2
Work practice analysis
Moulding two previously separate communities to work together
From the point of view of the Kuusamo Primary Health Care Centre,
teleradiology became a question of integrating and scheduling expert consultation
into the other constituents of patients’ care trajectory (Strauss et al. 1985). The
two previously separate communities of radiological work practice began to
60
cooperate in a distributed fashion. They had to revise their local ways of working
and establish new commonly agreed work procedures. The teleradiology system
replaced the peripheral awareness and face-to-face communication of local work
communities by asynchronous computer-mediated image transfer, request-report
exchange, and occasional phone calls on critical cases. Interactive cooperation
was replaced by distribution of tasks performed in geographically separate
locations at sequentially ordered times. The new teleradiology work practice is
depicted in figure 6.
Fig. 6. The teleradiology work practice between primary care and secondary care
consultant centre. (Co-author Helena Karasti is thanked for designing this figure.
Paper II, published by permission of Elsevier.)
The chain of tasks
After radiological examination of a patient and initial interpretation of images, the
attending physician in Kuusamo decides whether an expert consultation is
necessary, in which case he or she dictates a request for a consult. An X-ray
technician or secretary scans the films, enters the patient information, types the
request into the system and then sends them to the University Hospital. The
teleradiologist on duty at Oulu University Hospital checks once a day whether
images to be interpreted have been received. The radiologist then interprets the
61
images of each patient case on a computer screen and dictates reports. She or he
hands over the tape to the departmental secretary who types the report into the
system and sends the file back to Kuusamo Primary Health Care Centre. The
reports are received by an X-ray technician who prints them out to be delivered to
the attending physicians.
Activities aimed at ensuring a smooth flow of work
A great deal of work was carried out by the personnel in addition to the chain of
tasks directly related to using the teleradiology system. A continuous stream of
contingent support work was needed in “making the system work” (Bowers et al.
1995) as the patient case was taken through the consultation service. This
articulation work (Strauss et al. 1985) was carried out both in individual tasks and
on the level of cooperating the entire process. For example, prior to the image
transfer, the X-ray technician on duty prepares the patient folder. Films of the
patient’s previous radiology examinations are acquired, relevant films selected,
any missing information is checked and the patient material is organized. The
technician carries out all these measures to ensure a smooth flow of work in the
system while scanning, entering and sending information. Another set of
examples is of activities carried out to sustain an account of the service as a
formal sequential operation. The participants routinely checked whether they had
a task to carry out and after “completing their bit” made sure the next step was
completed, i.e., a sender in Kuusamo made a phone call to Oulu to inform about a
critical case, a radiologist handed over the dictation tape to a secretary, who in
turn, after typing out and sending the report, checked whether it was received at
the Kuusamo end.
The changed script of image interpretation work
In the film-based image reading practice, smooth flow of work for image
interpretation is ensured by a great deal of support work performed by other
occupations and easy-to-use technology in the form of films on autoalternator
light screens.
Radiologists are accustomed to interpreting images as sequentially ordered
processes of cases in series. The alternator supports this with its magazine for
light screens that are used for the temporary storage of organized films. In
traditional image interpretation sessions, the radiologists are accustomed to
62
reading the request concerning the following patient to determine the problem
formulation while the light screens are swiftly changed between the cases. As the
next patient’s pair of light screens appears, they take a quick overall glance at the
films and then proceed to a more detailed interpretation process and dictation of a
report. In a similar fashion, in a typical teleradiology image interpretation session,
a report was first displayed on the screen followed by images. The radiologist
would, however, have to wait idly while the images appeared slowly on the screen
one by one in blown-out-size and were then reduced to fit the pre-set frame for
each image. Then the radiologist would have to reorganize and resize the images
to suit the more detailed interpretation process. The system caused disruptions
and breakdowns in the smooth organization of work by imposing a new script for
image interpretation.
Dispersion of the patient records and the examination process
The radiologists are used to having a patient folder easily accessible on the
alternator’s desk during image interpretation. Should a need for more information
arise it can be referred to, at least for images of previous examinations with
accompanying reports and on occasion also for the patient’s medical record.
Material transferred via teleradiology from the primary health care centre is less
comprehensive than radiologists are accustomed to, being minimal (“it’s like the
patient was to a radiological examination for the first time”, “there is no history”)
or not sufficient (occasionally more images had to be requested to enable
comparison).
Dispersion of the examination process led to situations where the
teleradiologists did not have access to knowledge that is self-evident when the
examination is performed within close proximity of a department. They may miss
the locally produced knowledge related to the patient’s examination, patientrelated information (the patient’s physical appearance, conduct and behaviour,
and answers to the questions posed during examinations), and even recollections
of the patient’s previous examinations.
Dispersion of image articulation work
The radiologists need to be able to concentrate on the image interpretation work
during the sessions. To ensure an efficient flow of image interpretation, all imagerelated articulation work is carried out prior to the session. In the film-based work
63
practice at the Oulu University Hospital, the retrieval, checking, organization,
arrangement and layout of films on the alternator’s light screens was done by a
special assistant. With the studied new teleradiology system, the tasks
corresponding to the assistants’ work were dispersed into four aspects of the
teleradiology system-related work practice: 1) the scanning of films and
transmission of images in Kuusamo – which affects the final display order and
orientation, 2) the image display system – how it displays a series of images on
the computer screen, 3) how the radiologist arranges the images on the computer
screen at the beginning of a session and 4) the continuous image organization and
processing by the radiologist during the interpretation process.
In the teleradiology experiment, the radiologists ended up doing a great deal
of image-related articulation work both at the beginning of each case and during
the interpretation process itself. One factor contributing to the latter are the
enhanced image processing functions. During the study they were used as follows:
zoom function (enlargement) in 71% of the cases, image windowing and levelling
(brightness contrast adjustment) in 70% of the cases, image rotation (correct side
up) in 25% of the cases and image enhancement (unsharp mask function) in 3%
of the cases. Another contributing factor is the lack of system support for an easy
way of laying out images for juxtaposition on the screen. The radiologists’ part of
the system was designed based on the assumption that the transferred cases would
mostly be acute ones with few images. It turned out that 25% of the cases were
acute ones (report needed in less than an hour) while the rest were urgent ones
(75%, report needed in less than 24 hours). However, many of these were control
cases with numerous images (19% of the total number of cases), and even in the
acute cases comparison of images side-by-side was central to image interpretation.
To a great extent, the professional expertise of radiologists lies in being able to
follow a change through a series of images. This is traditionally done by
comparing films side-by-side on large light screens.
5.3
Internet teleradiology
Image quality, transmission time and interpretation time
In the first phase, image quality was found to be adequate with both
uncompressed and compressed images. Network transfers occurred without errors
or data loss. Data conversion between MS-DOS and Unix computer platforms
64
also occurred without problems. Image transfer times between Iceland and
Finland ranged from 2.5 minutes (compressed JIF file size 140 kbytes) to 43
minutes (uncompressed TIFF file size 2480 kbytes).
In the second phase, where only JPEG compressed images were sent, the
average image transfer time between Finland and Iceland was 3 minutes 45
seconds for an average image size of 270 kbytes. The average image transfer time
between Finland and Norway was 55 seconds for an average image size of 317
kbytes. As each study case needed two to three images, total on-line transfer times
ranged from 7.5 to 11 minutes (Finland-Iceland) and from one to three minutes
(Finland-Norway).
The average radiologist’s working time at the receiving site for the clinical
consultation cases was 8.5 min (range 5 to 14 min). This covered time from the
opening of images on screen to the end of the dictation session.
Comparison of screen and film readings in sellar pathology
The results of each group of three neuroradiologists and their combined reading
results in the second phase as analysed by the ROC study are summarized in
Table 3 and combined ROC curves are presented graphically in figures 7 and 8.
Table 3. Area under ROC curve derived from the analysis of the enlargement of sellar
contents and from the analysis of possible presence of microadenoma (III, published
by permission of Springer).
Evaluation of sellar enlargement
Evaluation of presence of microadenoma
Area under ROC curve
Area under ROC curve
Reader group
Screen
Film
Reader group
Screen
Film
Group 1 ISFI
0.874
0.869
Group 1 ISFI
0.762
0.803
Group 2 ISNO
0.884
0.933
Group 2 ISNO
0.755
0.823
Group 3 FINO
0.799
0.820
Group 3 FINO
0.613
0.590
Group 4 FIIS
0.848
0.848
Group 4 FIIS
0.758
0.738
Total 1-4
0.842
0.863
Total 1-4
0.758
0.717
ISFI = Sending Iceland -> Finland, ISNO=Sending Iceland -> Norway,
FINO = Sending Finland ->Norway, FIIS = Sending Finland ->Iceland.
There were no significant differences in readers’ performance between
teleradiology screen readings and film readings of the images either in each
individual reading group or in combined reading results for each study question.
65
Fig. 7. The combined ROC curves of all the readers evaluating the possible
enlargement of sellar contents. The area under the curve for teleradiology screen
reading is 0.842 and for reference film reading 0.863 (III, published by permission of
Springer).
Fig. 8. The combined ROC curves of all the readers evaluating the presence of
pituitary microadenoma. The area under the curve for teleradiology screen reading is
0.719 and for reference film reading 0.717 (III, published by permission of Springer).
5.4
Mobile PC teleradiology
In the final evaluation of the 68 consecutive neuroradiological emergency patients,
there were 22 normal cases and 46 pathological cases. The most common
66
pathological findings were brain infarction (16), haemorrhage (12) and atrophy
(7).
In all cases the consultations succeeded technically. The average data transfer
time (i.e. the FTP connection time) for a single compressed CT slice via GSM
was 55 s (total connection time one min). The transfer of an ordinary head CT
examination took 18 min on average.
The transmitted images were considered suitable for final diagnosis in 49 of
the 68 cases (72%) and suitable for preliminary diagnosis only in 19 of them
(28%). None of them were considered not suitable for diagnosis. The reasons for
suitability for preliminary diagnosis only were: the need to use a different window
and level (n=10), the need to compare to previous studies (n=7), or the need to see
more images than those selected for consultation by the junior radiologist (n=2).
The diagnosis from the transmitted images was the same as that from the
original images in 66 cases (97%) and slightly different (although no effect on
patient care) in two (3%). A small brain infarction in the posterior fossa region
remained undiagnosed and an artefact 2 mm in diameter was misdiagnosed as a
pons infarction.
Compared to an ordinary telephone discussion, the transmitted images gave
essential information in 55 cases (81%), beneficial information in eight cases
(12%) and minor benefit in five cases (7%).
According to the consulting radiologist’s opinion, the mobile image
consultation saved him a hospital visit for image interpretation in 16 cases (24%).
5.5
Smartphone teleradiology
5.5.1 Feasibility study
The 21 patient cases contained on average 14 images (range 3–20 images) per
case. The distribution of the diagnoses in original images was: 11 brain
infarctions, 2 atrophies, 4 haemorrhages, 1 aneurysm, 1 infection and 2 tumours.
Connection to the server was in all cases established with the first attempt.
The connection initializing time was on average 1 min 20 s (range 1 to 2 min). In
three cases the data connection was lost before all the images were transferred,
but a new connection was established after notification of an error message. There
was on average 2 min 40 s time (range 1 min to 6 min 50 s) to select the correct
images from the server. Image transmission to the terminal took 1 min 30 s per
67
image (including image transmission and file management time). The average net
transmission time for a head CT-scan was thus 21 min (range 4 min 30 s to 30
min). After the connection was closed the local interpretation of the images took
on average 15 min (range 7 to 23 min); the mean total working time on one case
was thus 40 min. There were no changes in the data contents of the transferred
data.
In one of the cases the image quality was good enough for a “final report”
and in 20 cases the quality was suitable for a “preliminary report”. There were no
cases in the category “not suitable for diagnosis”. The reasons for categorizing
images suitable for “preliminary report” were neuroradiologist’s doubts about the
suitability of image quality for interpreting small changes in 18 cases and need to
window and level the grey scale of the images in 2 cases.
The report given from the transmitted images was identical with the reference
film reading in 18 cases (86%) and not totally identical in 3 cases (14%). The
differences were: 1) a possible density loss at nucleus lentiformis was not seen, 2)
a small lacuna infarction at the right capsula interna region was not found, 3) a
pineal cyst was not found. In one case a pons infarction observed on the PDA
terminal by the neuroradiologist had not been noticed by a junior radiologist in
the original film report.
According to the neuroradiologist, the transmitted images gave essential
information in 5 cases (24%), beneficial information in 13 cases (62%) and minor
benefit in three cases (14%) compared to an ordinary telephone discussion. The
neuroradiologist considered that the image consultation saved a hospital visit in
15 cases (71%).
5.5.2 Clinical study
MOMEDA
With the second generation MOMEDA GSM terminal the sending time of a CT
scan series over the GSM network ranged from 15 to 20 min. The reading time
for a series of CT scans was 20 to 30 min for radiologists and less than 10 min for
neurosurgeons. The reading time for MRI scan series was longer, more than 35
min. This is mainly explained by the larger number of images in MRI
examination of the head compared to head CT. The image quality was sufficient
for final diagnosis in 38% of the 115 cases and for preliminary consultation in
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62% of the cases. The diagnostic quality was considered adequate and user
acceptance for emergency service was high. The costs of the transmission were
related to the transfer time. The demonstrator in this study showed that it is
medically sensible to use pocket-sized teleradiology terminals for consultation
purposes in neurosurgery and with limitations in radiology. This meant that the
final product was adopted for clinical use by the neurosurgeons of Oulu
University Hospital in June 2000.
PROMODAS
With the 2.5 generation PROMODAS GPRS terminal the transmission time was
cut down to 5 to 10 min depending on the network load. The image viewer
application had similar functionalities as the earlier terminal, but there were
considerable changes in the responsiveness of the system in favour of the
PROMODAS system, so user acceptance was high. New portable terminal
devices with faster processors enabled a more efficient processing and display of
patient information and the reading times were reduced to 5 to 10 min per scan
series. The confidence in image quality was somewhat higher than in the
MOMEDA project; now, image quality was considered good enough for final
diagnosis in 40% of the 150 cases, and in 60% good enough for preliminary
consultation. Telecom operators had now implemented a monthly flat fee work
for data, which made it possible to stay connected at a lower cost than previously.
In practice, the PROMODAS terminal replaced the earlier generation in clinical
use by neurosurgeons in June 2003.
The functional differences influencing the performance of MOMEDA and
PROMODAS are summarized in Table 4.
Table 4. Main functional differences between the two mobile teleradiology systems
(Paper VI, published by permission of Elsevier).
Parameter
MOMEDA
Network
GSM
PROMODAS
GPRS
Access method
Private Internet access point
Mobile IP via operator
Pricing scheme
Per second
Flat monthly fee
Average download time
less than 60 s / image
less than 20 s / image
Terminal display size
640x200 pixels
320x240 pixels
Image decompression time
more than 10 s / image
less than 1 s /image
69
5.6
Integration of teleradiology as a part of eHealth services
Coverage
Responses to the year 2005 questionnaire were obtained from all hospital districts
(100%, n=21). A total of 179 (71.3%) of 251 health care centres responded to the
questionnaire. The responses covered 88.2% of the whole population of Finland.
Additional data were also obtained from 27 health care centres that had not
responded to the present survey, but had responded to the 2003 survey.
Results were obtained from 28 private service providers, about half (n=13)
from the biggest private service providers and about half (n=15) from those
companies that had responded to the 2003 survey. The private providers included
enterprises, from conglomerates with hospital and operative services to small
part-time general practices. Because the private providers are a heterogeneous
group, the results concerning them can only be regarded as indicative.
The health care centres which did not respond were smaller in size than those
who did, covering only 12% of the population of the country. Therefore, the
answers obtained can be regarded as representative in terms of primary and
secondary health care. Because the public sector covers 85% of all health services,
the results can be regarded as representative for the whole country.
Electronic Patient Record
In specialized health care EPR was in use in all but one of the 21 hospital districts.
In one hospital district, EPR was in the planning stage at the end of 2005. Among
17 of the 20 users of EPR the intensity of use was over 90%. One hospital district
had intensity of use between 50–90%, and two between 25–49% In the year 2003
survey, 13 of the 21 hospital districts had EPR in use. In 2005, 18 hospital
districts indicated that the usage of EPR covered at least three out of four main
medical responsibility areas (conservative, operative, emergency care and
psychiatric care), while only 5 hospital districts had achieved this level in 2003.
In primary health care centres, EPR was in use in 240 (95.6%) of the 251
health care centres, three of them had it at testing stage, and eight at a planning
stage. In 2003 the coverage was 93.6% in heath centres. The 11 health care
centres lacking EPR in 2005 were small and remote, and some of them were
planning on converging with a larger neighbouring health care centre. The
70
intensity of use was very high: at 91% of the health care centres using EPR, the
rate was over 90%, while among the rest it was 50–90%.
Of the 28 responders of the private health care service providers, 25 (89%)
used EPR. Compared to the 2003 surveys the figures seem to be similar. The
intensity of use was high: three out of four providers had an intensity of use of
more than 90%.
Picture Archiving and Communication Systems
The results of the PACS survey for secondary care (hospital districts) in 2003 and
2005 are presented in Table 5. The progress has been fast during the two years.
Fifteen out of 21 hospital districts had a PACS in production in 2005. What is
more important is that they were practically filmless (over 90% of the medical
images were utilized only in digital form). The rest of the hospitals planned to
have their PACS in production towards the end of the year 2007. After that, all the
hospital districts in Finland have been totally filmless.
Table 5. PACS installations in 21 Finnish hospital districts in 2003 and 2005 (Reponen
et al. 2008, published by permission of IOS press).
Measure
2003
2005
PACS in production phase
10/21
15/21
PACS in pilot phase
1/21
2/21
PACS in installation phase
10/21
4/21
PACS usage > 90%
6/21
15/21
PACS usage 50–90%
3/21
1/21
PACS usage < 50%
4/21
1/21
Concerning primary care, in the year 2005 full picture archiving and
communication systems or system components were in use in 95 out of 179
health care centres (53%), based on the information provided by the vendors. In
the previous survey conducted in 2003, PACS usage information was obtained
directly from the primary health care centres; at that time, it was reported that
PACS components were used in 27 (17%) primary health care centres. Even
though the methodology is different, this information reveals that the use of PACS
at primary health care level has increased in Finland.
71
Results of regional services
Before presenting the results of many different and yet at the same time partially
overlapping forms of interorganizational data exchange, a couple of definitions
are needed. Electronic referrals are basically sent to another institution in order to
transfer the responsibility of patient care. Electronic discharge letters are then
returned to the sending institution once the patient’s treatment is finished. The
referral can evolve to an electronic consultation letter, if neither responsibility for
the patient nor the actual patient is transferred, but professional advice for
treatment is sought or professional opinions are given. Consultations can also take
place with a help of videoconferencing (televideo consultations). There are special
cases like teleradiology, which can be used for consultation but also for
information distribution; the same also applies to telelaboratory. Regional patient
data repositories or exchanges can serve many purposes: they can provide a
source of reference information for past treatment, a basis for current patient data
distribution in a geographically distributed health care environment, as well as a
data depository for consultation services and workload distribution. In a normal
medical practice, the various forms of data distribution complement each other.
e-Referral and e-Discharge letters
In 2005, the e-Referral letter and e-Discharge letter service was provided by 16 of
the 21 hospital districts. Rapid progress was made over a period of a few years,
because in 2003 the service was available in about half of the hospital districts.
In primary care, 45% of the health care centres made use of the service in
2005, while the figure was 24% in 2003.
Electronic and Televideo Consultations
Electronic consultation was provided by 11 of the 21 hospital districts, and it was
at testing or planning stages in the rest of the hospital districts, with the exception
of one hospital district.
About one third (36%) of the 174 health care centres purchased electronic
consultations from hospitals. Another third reported planning or having even
tested it. The health care centres purchasing electronic consultations seemed to be
very active with its use: in 70% of the 49 health care centres which answered the
question it was their principal mode for consultation.
72
In 2005, videoconferencing service was provided regularly by 10 of the 21
hospital districts, while five were in the testing or piloting phase.
Among 179 health care centres that answered the questionnaire, 21 (12%)
purchased video conferencing in order to consult a specialist at a hospital. In
addition, ten health care centres had been planning or were testing it. Although
specialist consultations by video conferencing were in 2005 provided by more
hospitals than earlier, the number of health care centres purchasing the service
had not increased from the 21 in 2003.
Regional Data Exchange Systems
According to the year 2005 survey, nine out of 21 hospital districts had a regional
patient data repository in clinical use for the exchange of patient data and six
districts were running pilot projects. There is no single closed network dedicated
to healthcare in Finland; technically, the connections are provided through the use
of commercial high-speed public data networks and secure tunnelling such as
VPN over the public network.
Teleradiology and Image Distribution through a Regional Archive
The results from the surveys conducted in 2003 and 2005 on teleradiology and
regional image distribution/archive services for secondary care (hospital districts)
are presented in Table 6. The usage percentage is also given, if available. Since
teleradiology services could be independent of local PACS or a regional archive, a
combined look at image transfer services is given. The key information is that in
2005, 18 out of 21 (86%) hospital districts utilized some form of electronic
distribution of radiological images.
Table 6. Teleradiology and regional image distribution services in Finnish hospital
districts in 2003 and 2005 (Paper VII, published by permission of IOS press).
Measure
2003
2005
Teleradiology in production phase
13/21
16/21
Teleradiology in pilot phase
4/21
2/21
Teleradiology usage > 90%
2/21
5/21
Regional archive in production
3/21
10/21
Regional archive in pilot phase
0/21
3/21
Regional archive usage > 90%
0/21
3/21
Either teleradiology or regional archive in use
13/21
18/21
73
In the primary health care sector, the combined results show that 52 primary
health care centres out of 179 (29%) had some method of teleradiological image
delivery in production. This is a remarkable increase compared to 2003, when 15
primary health care centres were using teleradiological image delivery.
Telelaboratory
In 2005, regional distribution of laboratory results through a regional archive was
utilized by 11 out of 21 Finnish hospital districts, one was at the pilot-project
stage and three were planning to provide such a service in the near future. In
addition, 16 out of 21 hospital districts utilized some other form of electronic
transmission of laboratory results to the primary health care centres in their region.
These other services were partially overlapping with the usage of the regional
archives. The combined results showed that a total of 19 out of 21 (90%) hospital
districts had some method for the electronic distribution of laboratory results in
2005. This figure has nearly doubled from 2003, when 10 hospital districts used
telelaboratory services.
In the primary health care sector, 48 health care centres out of 179 (27%)
reported in 2005 that they received daily laboratory results electronically through
a regional database, while 71 informed that they were either at testing or planning
stage.
Information Exchange between Health Care Organizations and Patients
Twenty hospital districts and 79% of all the health care centres maintained their
own websites. The hospital district and half of the health care centres who did not
have an individual website were running pilot projects or were planning the
implementation of their own website.
Information exchange with patients by SMS messaging was used by one and
tested by three of the hospital districts. It was used by nine (5%) health care
centres and tested by 11 (6%) of the 179 health care centres. With private
providers information exchange with patients by SMS was used by three (11%)
and tested by five (18%) of the 28 private providers.
Only one health care centre used secure e-mail in information networks,
while 15% used conventional e-mail. Remote browsing of EPR by the patient was
not in use anywhere, but was planned to be implemented by two hospital districts,
three health care centres, and one private care provider.
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6
Discussion
This work was conducted during a time period when teleradiology technology
advanced in great leaps. Therefore, the discussion topics touch a wide variety of
implementation issues, both technical and clinical.
The feasibility of commercial off-the-shelf technology for medical purposes
is related to the clinically acceptable image quality level, but also to investment
costs at that particular time. Radiological work practices have changed
considerably because of teleradiology, but also because of the digital radiology
environment in general. The Internet and mobile networks continuously give rise
to questions of adequate transmission speed and required compression ratio of
images. Likewise, portable terminals and even smaller smartphones challenge our
attitude towards display characteristics acceptable for different purposes. Security,
standardization and integration issues are crucial for all the implementations.
Because radiology as a medical speciality is serving other disciplines,
teleradiology should be investigated in relation to regulations and other digital
and remote medical services in the eHealth domain. The keywords of the most
common challenges are presented in table 7.
Table 7. Common challenges when building a teleradiology service presented as
keywords.
Hardware and software related
Communications related
Teleradiology service related
Cost of the equipment
Availability of connections
Work practice issues
Quality of the images
Speed of the network
Medical quality of the service
Usability of the equipment
Quality of Service
Liability, other legal aspects
Image compression rate
Cost of the network
Patient´s consent
Display characteristics
Security of connections
Reimbursement
Integration and interoperability
Mobility of the terminal devices
Language issues
It is interesting to note that these issues will come up again and again as
teleradiology is finding new frontiers from point-to-point to an international and
mobile setting.
Because of the time span and different technologies used, each of the
problems investigated in this study is first discussed separately in relation to the
work where it first appeared, after which common findings and development
trends are discussed.
75
6.1
Low-end technology teleradiology
In the case of high-standard film scanning teleradiology systems with resolution
equal to the original films and full 12-bit (4096 steps) grey scale with instant
image transmission, the price for a single-site unit at the time of this study could
be as high as USD 196,000 and a central referral unit may cost as much as USD
343,000. Network services make for additional costs if permanent connections are
used (Batnitzky et al. 1990, Dwyer et al. 1991, Templeton et al. 1991). The cost
of the equipment in this study was USD 20,000 for the transmitter and USD
15,000 for the receiver unit. This cost level made film-based teleradiology
feasible for health centres and smaller hospitals. The kind of dial-up ISDN lines
used in this study are available in all parts of Finland. Their fixed monthly costs
are only USD 20 to 100, depending on the amount of simultaneous channels used,
and the connections are paid by use, the price being that of normal long-distance
calls.
In their report on the use of low-cost, low-end digital teleradiology Lear et al.
(Lear et al. 1989) built a system based on a prototype high-resolution CCD
camera, a personal computer and an ISDN link. Their equipment and software
were however proprietary and not commercially available. Dohrmann et al.
(Dohrmann 1991) used personal computers to establish a low-cost teleradiology
link in Australia. They used a video camera and a frame grabber to capture the
images from printed films, however. A slow-speed (2,400 bit/s) ordinary
telephone line modem was used to transfer images. This solution limits maximum
resolution and transfer speed and is mostly suited for CT images. Yamamoto et al.
(Yamamoto et al. 1992) built their low-cost teleradiology equipment out of
personal computers and handheld scanners. Their scanning area was limited to 6.1
× 7.0 centimetres, and an ordinary telephone line was used for transmission.
The on-line sending time for a 10:1 compressed chest image (size before
compression less than 4 megabytes) in this study was at the same 30 sec level as
reported by Goldberg et al. (Goldberg et al. 1993) for an uncompressed 7
megabyte image over a fast 1.544 Mbit/s network. If efficient compression can be
used, even ISDN networks can serve effectively for this purpose. Only a few
studies, however, discuss the total procedure time for teleradiology (Carey et al.
1989, Lear et al. 1989, Slovis & Guzzardo-Dobson 1991). In the present study,
when efficient compression was used, film digitization together with other
preparations took up more of the total procedure time than the actual sending.
76
The transmitted images were scored as technically acceptable with 8
exceptions (3%). In seven cases the inadequacy was due to improper scanner
settings or insufficient grey scale dynamics. Because the scanner in the present
study limited the image grey scale to 8 bits (256 levels), parameters such as
brightness and contrast were critical for good image quality. If the original images
present excessive contrast, details in both the dark and the light areas may be lost.
This means that such images should be sent in duplicate for the dark and light
areas. Another solution is an image scanning program which can decrease image
contrast by making the highlights darker and the shadows lighter (thus modifying
the response curve in the digitalization process). This method was used in phase
three (from the regional hospital). True 12-bit (4096 levels) scanners that are not
so operator-dependent are three to four times more expensive than the unit in this
study.
Image spatial resolution was sufficient, except in mammograms. The
maximum scanning density of the tested system is 300 DPI, which equals 11.8
pixels per mm. This exceeded the scanning density of the Fuji AC-1 CR image
plate system, for example. In practice, in the present study the scanning density
was finally set to the same level as in the CR image plate system for chest (129
DPI = 5.1 pixels/mm) and bone (165 DPI = 6.5 pixels/mm) images. If the
maximum scanning density of the tested scanner had been used all the time, the
image sizes would have been too large for the equipment in this study. A 35 × 35
cm chest x-ray with 300 DPI (11.8 pixels/mm) resolution would require more
than 17 megabytes and could not be loaded into the 8-megabyte memory of the
computer.
There were no significant differences in the diagnoses of technically
acceptable chest or bone images. In two CT images, a small pons infarction and a
slight thickening of the nervus opticus were missed in the original screen reading.
In retrospect, however, these lesions were detected. It seems that the errors were
due to the reader’s unfamiliarity with the computer screen. The opportunity of
film printing might have been an advantage, but on the other hand, when picture
archiving and communication systems are taken into use, computer workstations
become a common workplace for radiologists. In mammograms, the error
frequency was markedly greater, 10%, suggesting that the scanning resolution
used in this study was not sufficient for transmission of the most detailed films.
The results of this study, with their total 98% agreement on the technically
acceptable images, correspond well to the results by Carey et al. (Carey et al.
1989), who sent 489 laser-digitized conventional and US examinations with 98%
77
agreement between the original and transmitted images. It is notable that they still
had 12 patients in whom disease was not correctly identified even though the
original films were digitized with 12-bit grey scale. Slovis et al. (Slovis &
Guzzardo-Dobson 1991) also had an agreement of 98% in their work with 4,200
conventional paediatric images. Goldberg et al. (Goldberg et al. 1993) had
discrepant interpretations in 18 (2.6%) of 685 cases while using a 12-bit scanner.
When standard computer programs are adapted for clinical work, some
limitations are encountered. The programs may not have been specifically
designed for medical work and require many adjustments. In the first two phases
of this study, the participants had to perform all the preparatory steps and make
the changes from the viewing program to the transmission program. This was the
reason why they let a computer operator send the images from the health care
centre. This caused some quality problems because the computer operator was not
accustomed to making decisions on the technical quality of scanned images.
The easier graphical interface, the “shell” used in phase three, resulted in
more convenient image transmission. It eliminated complicated steps and required
less training. It made it possible for x-ray technicians to transmit the images as
part of their normal daily routine without being too much concerned with the
technology. This is important, because x-ray technicians cannot spend too much
time on teleradiology efforts. The x-ray technicians were also able to maintain a
constant image quality. This is important for the cost-effectiveness of the system.
If a teleradiology system is based on standard low-end personal computers,
one has to be aware of the limitations. Depending on the scanner, the grey scale
dynamics and scanning density might not be sufficient for the most detailed
images, such as mammograms. In addition, the smaller display unit necessitates
the use of image zooming. If these problems could be resolved, the same central
unit could be used for office automation, Medline literature searches and
scientific image processing. Radiologists who are familiar with computers do not
need to learn a new user interface, but can utilize the skills they already have.
Images are also transferable into teaching programs and archives, for example.
Our investigation suggested that good image quality can be restored in the
transmission of images with the standard personal computers tested and a
commonly available commercial software configuration. This could make it
possible to build low-end technology teleradiology links for special purposes at a
lower cost compared to the commercial high-end systems. However, this study
was not specifically focused on making a detailed cost analysis of teleradiology.
One should bear in mind that the fixed costs related to equipment are a function
78
of the equipment existing on the market at that time and all the economic
conclusions are therefore related to the specific equipment and specific
teleradiology setting.
According to the experience in this study, the scanner is the most critical unit
and its 8-bit grey scale should be extended. In this system, the total sending
procedure still took a relatively long time, and the manoeuvrability of the system
was thus another important limitation. Concerning clinical application areas, the
system investigated here was not suitable for mammographic image transmission.
6.2
Work practise analysis
New technologies necessarily provoke changes that go beyond the technical
system itself. The work practice-oriented study of everyday clinical teleradiology
work clearly illustrates that this is also the case with teleradiological systems, and
it should be taken into account in designing and implementing them in practice.
The study reveals important aspects that have previously gone unnoticed or been
invisible (Plowman et al. 1995). For example, the articulation work done to
ensure the smooth flow of the teleradiology service made up a major part of the
work process both in terms of the amount of activities and importance for the
whole process. Several aspects of cooperative work between the two
geographically separate radiology communities were also identified. Moreover,
articulation work and issues dealing with cooperation were neglected or
underestimated in the system design and organization of teleradiology work
practice.
From radiologists’ point of view, it is important that the system does not
interfere with the accustomed script of interpretation and reporting by causing
disruptions and breakdowns. On the other hand, it has to be kept in mind that
established work practices have been historically formed in close relation with
associated technologies. Therefore, former working habits cannot always be kept
in place as a standard way of working but should be critically evaluated. The
work practice-oriented approach also proved to be useful in detecting those areas
of work that are essential for the primary goal, i.e. accurate interpretation of
images. The system should support the essential parts and typical tasks of work.
Image comparison is an elementary component in radiologists’ work.
Computer screen-based image interpretation technologies cannot supply as much
display space as the radiologists are used to having with traditional light screens.
However, the need for the system to allow for easy juxtaposition of images
79
remains. The lack of display space has to be compensated in another ways by the
digitized images and computing power. Comparison could be made easier e.g. by
always displaying chest studies on the screen in the same order. New display
techniques, like stack or cine mode, could be used more often while reading a
series of CT images. There is evidence in literature, that his will enhance the
reading speed (Mathie & Strickland 1997, Kim et al. 2005b). Another aspect
contributing to the ease of comparison of images is the image articulation work
that is done as much as possible prior to the actual sessions. It remains to be seen
to what extent this can be supported automatically by the system, as there seems
to be a great deal of tacit knowledge involved in the articulation work carried out
by the assistants. Unnecessary image arrangement tasks during the interpretation
session should be avoided because they are time-consuming and can weaken the
radiologist’s concentration on the image reading process itself. The initial image
display should give an overview of the kind of images there are to be interpreted.
A structured way of showing the time order of images is also useful. The interface
should be simple, with only relevant buttons and menus, so as not to hinder the
interpretation process.
In the system studied here, the most often used image processing tools were
adjustment of brightness and contrast as well as image zooming. Even though
these features need training and take some time, they offer advantages by
revealing diagnostic information that is otherwise not as easily noticeable. The
investigated system had brightness/contrast control in the mouse, and some
radiologists used it in an interactive way even while examining various parts
within one image. More complicated image processing features seem not be
needed in the busy routine praxis.
Improvements to system usability were identified during the study. Some
specific design guidelines for the development of the system were provided.
However, this remains an area where more empirical work is needed, as the
introduction of new technologies is always a process of learning and adaptation as
well as innovation.
The workshops helped a new work community emerge around the new
system, as the simplest method is to let people from both ends meet each other in
person! The personnel were able to discuss and compare their local procedures,
and see for themselves how the work was carried out at the other end. This helped
in building a shared understanding of the cooperative work process and in
agreeing on common procedures – which is often a complicated issue with
distributed systems. It is important to involve not only final end-users of the
80
system but also representatives of all of the tasks that will be changed by the
system in the design process. This kind of approach is thus recommended when
implementing new telemedical services.
New technologies may introduce tasks that are altogether new; in this case
such tasks included the scanning and sending of images in Kuusamo Primary
Health Care Centre. It is important to adapt the new or modified tasks to local
conditions and other practices that will exist in parallel when the system is used.
Furthermore, it is important to identify what kinds of skills and knowledge are
needed in the new tasks: not only training in skills for the new application
programs or one’s own tasks is needed, but also knowledge of the tasks of others
and one’s own role in the system as a whole to help in adjusting to team work.
In the system studied, texts (requests and reports) and images were linked
together. This approach is different from many teleradiology systems, where only
images are transferred electronically while texts are sent via telefax (Goldberg et
al. 1993, Davis 1997, Poca et al. 2004). The approach used in the studied system
makes it easier to combine patient information and refer back to earlier cases.
However – from the point of view of clinical praxis – an even more extended
connection to patient records is preferred. Image comparison would be easier if
earlier images could be acquired from a digital archive whenever needed. A
hospital should maintain a common regional archive together with primary health
care centres connected to it. This would increase the quality of care by making the
diagnoses more accurate and also decrease unnecessary retakes as the patient
moves from one institute to another. In addition, the report texts need to be
integrated to the EPR. During the study, the primary health care centre printed out
the reports in paper form. The goal is that physicians can automatically receive
reports directly into their terminals. At that point, teleradiology would finally
support medical work flow as part of vital patient information.
6.3
Internet teleradiology
The value of this early study was that it showed the potential of the Internet,
because only a few cases of international teleradiology had been reported earlier.
This work also highlighted the common issues that are constantly relevant in
connection with this type of distant communication.
The technical quality of digitized and transmitted images was found to be
adequate for diagnosis. A common image file format and common transmission
protocols available for Internet connections made it possible to establish links
81
between different institutions in different countries. Standard data format
developed for medical images (DICOM) will make this even easier in the future.
The value of the Internet is its wide availability – connections are made using
existing networks. This can help in sharing medical expertise in various part of
the world in a way not experienced before and open new possibilities especially
to the developing countries (Wootton et al. 2005). The openness of the Internet
can on the other hand cause problems with data safety. Encryption of patient
identification data is therefore needed in clinical use. For certain purposes even
anonymized data can be used, where all patient ID information has been removed.
The Swinfen Charitable Trust has successfully used the anonymization principle
in their charity low-level telemedicine e-mail consultations for the third world
since 1999 (Vassallo et al. 2001). In any case, hospital networks must also be
protected by firewall systems against intruders from outside.
Because of different transfer speeds between links, sending times can vary a
lot. The speed of the fastest connection in the work discussed here was 2 Mbits/s
and that of the slowest 9.6 kbit/s. To increase the throughput within such a slow
channel, efficient data compression is necessary. Even though data transmission
speeds have steadily increased within the Internet as well, and in 2010 Funet
member organizations connect to the new routers with either 1 Gbit/s or 10 Gbit/s
connections (CSC 2010), no QoS can be guaranteed. This is however not a major
concern in the “store and forward” type of practice used in teleradiology.
Commercial dedicated wide area networks have promised to fulfil the
requirements of speed and data safety. Their problem is, however, that
international connections are either not widely available or that they are still
expensive. There are only few examples of dedicated health care networks that
cross national borders, one of them being the Scandinavian health network
(Duedal Pedersen 2004), which connects Medicom in Denmark, Carelink in
Sweden and the Norwegian Healthnet.
Therefore, secure connections over the Internet and compliance with the
DICOM standard in file format and transmission have been used for offshore
teleradiology services, e.g. examinations made in the US are read in reading
centres in Australia and Switzerland (Bradley 2004, Bradley 2008).
The effectiveness of a remote consultation system is not only a matter of time
and technical image quality; informal additional information also needs to be
negotiated during the consultation sessions. Special consultation software with
multimodality capability (video, speech, cursor synchronization) is an advantage
(Ligier et al. 1993).
82
In this study with a few real consultation cases a secondary sub-specialist
opinion between university hospitals was considered useful, because the way
medicine is performed was similar between those participated institutions. For
small scale secondary opinion consultations between experts the language issue
was not a problem, as medical English was used here. In the case of larger-scale
consultations between the clinical physicians and radiologists the language issue
becomes more relevant. E.g. in the European Baltic eHealth project the language
issue was recognized as the biggest barrier to overcome in cross-border
teleradiology (Ross et al. 2010). Therefore, they created a structured reporting
tool to overcome this barrier and used that in consultations between the Baltic
states and Denmark. Also multilingual transcriptionists were used. They also
verified the medical quality of the reports before entering to production phase.
Today, the success of cross-border teleradiology seems to be more dependent
of organizational and quality issues than on pure technology. Also legal issues
need more clarification (Stanberry 2006, Pattynama 2010).
6.4
Mobile PC teleradiology
The benefits of teleradiology have been especially apparent in neurological
emergencies (Lee et al. 1990, Spencer et al. 1991, Gray et al. 1997, Hazebroucq
& Fery-Lemonnier 2004, Ashkenazi et al. 2007, Kreutzer et al. 2008,). Fixed
connections like computer networks or telephone lines have mostly been used
(Batnitzky et al. 1990, Dwyer et al. 1991, Stewart et al. 1992). This limits the
mobility of a consulting senior to a certain place. Yamamoto published the idea of
using wireless communication and portable computers for radiological
consultation (Yamamoto 1995). However, analogue wireless communication
involved transmission errors and the effective speed was slow. The digital GSM
technology used in this study gives reliable connections and tolerable
transmission speed with compressed images. In digital form the data remain
unchanged.
The relatively slow speed of the GSM network requires special techniques to
keep total connection time on an acceptable level. To reduce the required
bandwidth, we used JPEG compression for the images. In various studies it has
been shown that a slight compression with a compression ratio from 1:10 to 1:15
does not affect diagnostic quality of radiological images (Lo & Huang 1986,
Ishigaki et al. 1990, MacMahon et al. 1991). The system in this study was
constructed using existing networking and image processing standards. Image
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compression is also available for the DICOM format. Mobile telephone networks
are becoming faster and thus more suitable for image consultations.
The resolution and contrast of the active matrix display system of the portable
computer used in the present study was sufficient for CT work. In particular, the
relatively high luminance compared to older passive matrix screens was found to
be suitable for CT reading. The active matrix display itself was capable of
showing 256 colours with adjustable brightness. The screen in this investigation
was better than in an earlier study, where a 16 grey-shade display was not found
good enough to display X-ray images adequately (Yamamoto 1995). Modern
laptop computers seem to be appropriate for clinical work. In this investigation,
CT-images were interpreted with high reliability.
One of the limitations in the system studied was display size. In one case the
neuroradiologist would have liked to review the images side by side. An
alternative is to use cine mode or a zoom tool of the image viewing software.
Bigger flat screens have become available for portable computers, too.
One of the reasons why experts considered some images only adequate for
preliminary diagnosis was their inability to change the grey scale window and
level. This is not related to the display technology, but to the file format used. In
image file conversion, the original pixel depth is compressed from 16 to 8 bits.
This means that in the studied system the images had to be windowed by the
sender in order to optimize their visualization. This causes problems, if, for
example, bone structure has to be interpreted and only soft tissue images have
been sent. If DICOM format images would have been used, the receiver could
have adjusted the images.
In other cases the neuroradiologist was only able to give a preliminary
diagnosis, because previous images would have been needed for comparison.
With electronic archiving, these will be readily available on-line. This suggests
that any teleradiology system should have a link with hospital PACS.
In the study series, the two slight misdiagnoses caused no change in treatment.
The first one appeared in the very first case in the study series and was due to
uncertainty about the capabilities of the computer. This emphasizes the
importance of individual experience with any new computer tool. The
neuroradiologist was familiar with PC teleradiology, but had used a tabletop
computer with an ordinary cathode ray tube (CRT) display. More aggressive use
of brightness and contrast adjustment would have helped in making a correct
diagnosis. The second case was difficult to decide even from the original image.
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When widely-available network tools are used, data security is an important
issue. The system studied here used a private dial-in server with user
authentication requiring a password. No public computer networks, such as the
Internet, were used. In the GSM network itself, the data are transmitted in
encrypted digital form, and no additional encryption is thus needed.
The usefulness of communication technology enables more efficient use of
expert consultation. Patient care is more efficient and economical when a final
diagnosis can be made at an early stage. This is very important in neurosurgical
emergencies (Richter & Braun 1993). Consultants can react more promptly if they
do not have to travel to a hospital to give their opinion. When hospital-wide
image networks are built, remote links should also be considered. With mobile
communication, experts can be reached if required, wherever they are – even in
another country. This type of sub-specialist expertise could be useful in
circumstances where the health care delivery system is similar, e.g. in the sparsely
populated northern areas in the Nordic countries
With modern technology, it is now possible for a radiologist to carry a
toolbox for CT scan interpretation in a briefcase. The main limitation in wireless
communication is the data transfer speed, but the situation is steadily improving.
The presented initial study confirmed the feasibility of mobile PC teleradiology.
6.5
Smartphone teleradiology
6.5.1 Feasibility study
Clinical results
No studies were found in the literature on pocket-sized teleradiology terminals
using intelligent phones or PDA-devices with combined digital phone capabilities
in one device (a smartphone) before this investigation was accomplished.
Wireless transfer of radiology images to a portable computer has been reported
with analogue and digital technique (Yamamoto 1995). He also published at the
same time a small series of 5 transmitted images to a pocket computer with a
separate wireless modem connection (Yamamoto 2000).
Image reading on a smartphone-type PDA-device was capable of serving as a
preliminary reading station: no significant findings went unnoticed and a senior
opinion could be given. A possibility to window and level the images might have
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helped in detecting missed secondary findings. Actual reports showed a good
agreement with reference film reading; only 3 cases had minor differences,
although the neuroradiologist originally scored 20 cases in the category
“preliminary report”. On the other hand, smaller findings can also go unnoticed in
the case of film reading, as happened during this study for a small pons infarction,
which was at first attempt only detected on the PDA terminal by the
neuroradiologist. Using a PDA terminal was found suitable for reading the most
common emergency CT findings like haemorrhages and brain infarctions, and it
gives added value by enabling clinical consultations (by a neurosurgeon or
neurologist) based on images.
Technical limitations and expectations
Although the PDA devices are small enough to be carried in the pocket, their
networking and display technology must improve before they are more widely
accepted as teleradiology terminals. Unlike many other telemedicine solutions,
the cost is not a major barrier. Because off-the-shelf technology can be used, the
cost of the terminal devices remains low. With the data call costs at the time of the
study in Finland (0.20 Euros/min) the connection costs of a 30-minute session are
also acceptable (6 Euros). Currently, there are several different vendors providing
PDA devices on the market. Until recently, communication with these devices
was complicated. The Nokia Communicator 9000 was the first device to
successfully combine a PDA with a GSM-phone and make connectivity easy to
use for everyone.
The limited grey-shade resolution of the investigated PDA device was
probably the limitation behind the difficulties to notice very small changes.
Another limitation was the small screen pixel amount (even less than VGA). Both
of these limitations can be partly solved by display software by providing tools
for windowing and levelling the image as well as functions to zoom and scroll the
image. Flat panel display technology itself is also evolving fast. Third-generation
mobile terminals and phones will be capable of showing more grey-shades and
pixels and even sharp colour images on a small display. If the power consumption
of these new displays can be set to a reasonable level, image quality in a portable
terminal will no longer be an issue. It is also possible to design the telemedicine
service so that several optional devices can access the system. Some of the
portable devices can also be connected to larger external display devices.
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One might also ask how small displays could suffice in portable devices
when at the same time a great deal of attention is given to the requirements and
quality control of image reading displays in the radiology department and clinical
wards. The answer may partially be related to the main purpose of these devices.
For clinical decision-making, when there is no other option to get access to
images, these devices provide a helping hand. In addition, many findings
especially on cross-sectional CT and MRI images that are relevant to the clinical
question at hand can be visualized with lower resolution requirements, if the tools
are carefully used.
One of the biggest restrictions of communicative PDA-technology in this
study was the available bandwidth. The standard GSM data speed is 9.6 kbit/s,
which restricts considerably the amount of data that can be transferred. The
situation where multiple images in a CT scan series can be sent on average in 21
minutes is just within acceptable limits. However, one uncompressed chest X-ray
image is 10MB in size, for example, and it would take several hours to transfer it
over the GSM-network. In the work of Yamamoto and Williams (2000) viewing
times from turning on the pocket computer to viewing the entire image ranged
from 4 to 6 minutes, but only single images were sent, not series. Reliability in
obtaining a wireless Internet connection was good, but not perfect. In the studied
case with a dedicated device, reliability in connections was not considered a
problem.
Faster GSM network enables speeds up to 14.4 and 57.6 kbit/s. The first 14.4
kbit/s commercial service started in 1999. These higher speeds are achieved by
high-speed circuit-switched data (HSCSD) technology by using multiple time
slots for the data connection. Other approaches to speed up mobile data
transmission in wide area networks are GPRS and EDGE. Finally, 3G (UMTS)
technology with wireless data rates of up to 2 Mbit/s became commercially
available in the mid-2000s, its latest high-speed downlink packet access (HSDPA)
developments giving in 2010 a theoretical mobile data speed up to 14.4 Mbit/s
depending on the capabilities of the network and terminal devices.
There are also other global possibilities for wireless communication, such as
mobile satellite services (Lamminen 1999). Their restriction compared to cellular
networks is higher price and unavailability of integrated PDA devices. In
summary, the spectrum of wireless communication for medical purposed covers
radio pagers, radios, cellular telephones, satellite communication and personal
communication services (Yoho 1994).
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Rapid development in network technology means that mobile systems will
come close to LANs in performance and that in the years to come, transmission
times will no longer be a barrier, at least not in the vicinity of urban settlements.
The latest development in mobile network family, fourth-generation mobile
networks (4G) like LTE (long time evolution) wireless networks can theoretically
provide downward links to the terminal with speeds of 100 Mbits/s, which is in
the magnitude of fixed wired networks. The world premier for these networks
took place in December 2009 in Stockholm and Oslo (Wikipedia 2010).
For medical purposes, network security is an issue. The digital GSM system
is inherently more secure than analogue systems due to its use of speech coding,
digital modulation and TDMA (time division multiple access) channel access. The
additional security mechanisms (such as authentication, encryption and temporary
identification numbers) specified in the GSM standard make it one of the most
secure telecommunications systems that are publicly available. Eavesdropping a
GSM transmission is currently considered only a minor risk.
Usage areas
In emergency cases the ability to obtain advice for interpreting radiographs from a
non-resident senior doctor seems to be very beneficial. It may be especially
important in cases where decision on treatment options must be made in just a
few hours.
At present, PDA technology may not always be good enough for detailed
diagnosis but it may be of great help in many clinical consultations where the
radiological diagnosis is evident and the question concerns treatment actions. The
majority of users may thus eventually be non-radiologists.
The method was found suitable for clinical diagnosis of brain attacks.
Intelligent phones, which can be carried in the pocket, make it possible to reach
radiology consultants regardless of place. In the future, clinical consultations of
e.g. neurosurgeons and neurologists will become easier, thus facilitating earlier
treatment in the case of serious diseases like intracranial haemorrhages. Timely
clinical specialist consultation has become more important not only in
neurosurgical emergencies but also in the treatment of brain infarctions, where,
according to the general guidelines, thrombolytic treatment should be started
within three hours after the onset of symptoms (Käypä hoito 2006). It has been
estimated that the main cause of delay in starting stroke treatment with
thrombolytic drugs is the time required to perform the CT-scan. Part of the delay
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may come from the delay of interpreting the examination. In future, the PDA
terminal may speed up this process by providing direct access to the right expert.
6.5.2 Clinical study
Network issues
In the latter PROMODAS part of the clinical study, the faster download times
between 5 to 10 minutes were achieved for a full series of CT or MRI scans using
GPRS network technology. Even though mobile teleradiology in this manner is
already feasible for special purposes and can be used clinically, standard mobile
telecom networks still provide rather slow data transfer speeds. As mentioned
earlier, the 3G networks (UMTS) and its 4G (LTE) successors are breaking this
barrier by bringing real broadband to mobile devices. Another interesting wireless
broadband technology is WLAN (Pagani et al. 2003), but its previously discussed
geographical limitation of being available only in so-called service points, “hot
spots”, means that it is usable only as an alternative or supplementary
communication network for health professionals.
Terminal device and software development
Handheld devices are becoming more and more powerful tools. The
computational capabilities are reaching the levels needed for many medical
imaging requirements. The devices used in the PROMODAS project were already
acceptable in terms of computational power. The image manipulation functions as
well as rapid change of images were considered good enough for consultation
purposes. However, as we are still in a phase of rapid development in mobile
technology, the lifetime of mobile devices is rather limited. In practice, more than
3-year-old devices can be considered outdated.
Because of the advances in network technology, but more importantly,
because of the rapid progress of terminal devices and their operation systems, the
development costs of consultation systems described in this study may rise
compared to the expected lifetime of the applications. A new generation of
devices every two to four years means challenges to both the technology provider
and the user site. This problem can be alleviated by careful system design. For
example, the DICOM standard can be considered a rather stable technology and it
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should be used where possible. Similarly, general Internet-technology may be one
solution: platform-independent applications may release us from platform
dependence. The standardization of information transfer, contents and formats is
needed for data exchange.
At the time of this study, the MDD was not yet implemented to telemedicine
software. In the future, the directive will have an effect on the development cycle
of software for mobile devices. The evaluation of their safety and clinical
feasibility has to be conducted in a regulated manner. However, in this study
clinical evaluation was performed when diagnostic accuracy was compared to the
original data on full-size image reading terminals.
Most recently, PDAs have continued to advance with faster processors and
faster wireless network connections, increased storage capabilities and improved
screen resolutions. The Apple iPhone (Cupertino, CA, USA) released in 2007 has
a screen resolution of 480 × 320 pixels in colour with high luminance LED
backlight; its newest version, iPhone4 released in 2010, has a screen resolution of
960 × 640 pixels with a contrast ratio of 800:1 and a 500 cd/m2 brightness. A
tablet size variant called iPAD already has a 1024 × 768 pixel resolution. In a
recent study the luminance and contrast response of iPhone/iPodTouch displays
was in the level of high-end commercial laptop displays and even medical display
quality control phantom performance was adequate (Kondoh & Okuda 2010).
High-resolution displays have also become standard in the Android and Symbian
family of mobile phones. A new phenomenon in these operation systems is an
easier way of making small applications (apps) to the new smartphones, so that
there are already thousands of medical apps available. In addition, almost all
PDAs now offer the ability to connect to standard WLAN networks, in addition to
standard cellular networks. These portable devices will only continue to improve.
Clinical experiences
Also other research groups have shown the clinical usefulness of PDA devices in
remote image consultation. Raman et al. (2004) have developed a PDA-based,
DICOM-compatible teleradiology system that is capable of vendor-independent
seamless integration with a PACS. Their system incorporates a Web interface and
custom viewers for Palm OS and the Windows CE operating system, making it
compatible with most PDA models available at that time. Their custom PDA
image viewer software provides basic patient information and image management
and viewing functions. The system supports compression and encryption and is
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compatible with most wired and wireless communication methods. Although
some hardware and software limitations still remain with respect to the
development and implementation of the system, many of these limitations will be
overcome in the near future thanks to ongoing development. Their experience
showed that PDAs are capable of serving as a powerful platform for mobile
image review and management. They expected that in the future, as high-speed
wireless networks become ubiquitous, personal handheld devices will become an
important platform for image review and reporting in the radiology department
work flow and will enhance communication with referring clinicians.
In their study, Yaghmai et al. (2004) found that PDAs are an effective way of
transmitting 256 × 256 pixel resolution images through a PDA using the CDMA
(code division multiple access) wireless network. These images were sent using
standard e-mail clients, and the terminal used was a standard commercially
available Treo-270 communicator PDA (palmOne, Milpitas, CA, USA).
Instant transmission of radiological images may be important for making
rapid clinical decisions about emergency patients. Kim et al. (2005a) examined an
instant image transfer system based on a personal digital assistant (PDA) phone
with a built-in camera. Images displayed on a picture archiving and
communication systems (PACS) monitor can be captured directly by the camera
in the PDA phone. Images can then be transmitted from an emergency centre to a
remote physician via a wireless high-bandwidth network (CDMA 1 × EVDO,
evolution data optimized). They reviewed radiological lesions in 10 normal and
10 abnormal cases produced by modalities such as CT, MR and DSA. The images
were of 24-bit depth and 1144 × 880, 1120 × 840, 1024 × 768, 800 × 600, 640 ×
480 and 320 × 240 pixels. Three neurosurgeons found that for satisfactory remote
consultation a minimum size of 640 × 480 pixels was required for CT and MR
images and 1024 × 768 pixels for angiography images. Although higher
resolution produced higher clinical satisfaction, it also required more transmission
time. At the limited bandwidth employed, higher resolutions could not be justified.
The strength of this study was that it demonstrated that the mobility and
portability resulting from the use of a personal digital assistant (PDA) in an
emergency setting was beneficial, as it did not require the consultant to be
available in a fixed location. However, the patient material was small compared to
our clinical series.
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Integration to medical record systems
Teleradiology services can be utilized to their full potential only if they are
integrated with EPR systems. Therefore the development of an initial mobile
physician terminal was continued to clinical phase within the EU fourthframework projects MOMEDA and PROMODAS, both working with technology
and process. One of the key elements in this project was to make technology more
user-friendly, so that e.g. image transmission can take place in the background,
without user interference. Thus it helped overcome the time delay spent on file
managing found in the present study. The wireless terminal for a physician
enables receiving of images, text and other components of multimedia patient
record regardless of time and place. It is connected both to the radiology image
network and to the comprehensive EPR system of Oulu University Hospital. The
EPR is a multimedia record using WWW approach (Reponen et al. 2004), so
additional information can be fetched with the common HTTP (hypertext transfer
protocol) protocol. This means that the presented smartphone terminals gave full
access to the medical record and not only to the radiological part of that. In this
aspect the studied MOMEDA and PROMODAS terminals had an advantage
compared to other studied terminals in literature.
New models of work
This development of personal wireless terminals may mean that some of the duty
services can be centralized and that fewer physicians are needed during dutyhours. In the future, hospitals can directly consult e.g. neurosurgeons,
neurologists or orthopaedic surgeons by sending images and referral letters to
their portable devices. Ideally this will lead to re-engineering of current health
care processes, freeing resources. Wireless workstations will also revolutionize
the development of EPR in hospital. One of the biggest barriers of EPR
development has been the cost caused by the distribution of enough workstations
in the hospital to allow access to EPR from different work spots. Wireless
workstations will give health care professionals liberty to move around and yet
have fast access to the EPR using various wireless LAN-technologies and even
switch between mobile data networks (3G) and WLAN with the same device.
While the various barriers are lowering, the future telemedicine will be
integrated tightly into the normal care processes and the technology that is needed
will be in the routine toolbox of health care professionals. The patient is the final
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winner when medical professionals can access information in the most practical
way.
6.6
Integration of teleradiology as a part of eHealth services
The present study is part of a continuing survey, which follows the
implementation of the Finnish national eHealth roadmap. The ideas are based on
the European eHealth action plan (2002), e.g. citizen-centred and patient-centred
services, full continuum of care and the well-informed patient. This series of
studies reveals data for administration and planning and even for international
benchmarking.
Teleradiology has been one of the first applications of telemedicine in Finland.
According to a Finnish study, all the five Finnish university hospitals already had
teleradiology services in 1994 (Reponen 1996). Regular service first started in the
sparsely populated northern areas, but has since spread to all parts of the country.
In the primary health care centres, the current trend is not to have a PACS of
their own, but to combine efforts with a local regional hospital or with a larger
hospital district. There are many innovative solutions available. For example in
the most northern hospital district in Finland, all primary health care centres that
produce x-rays are fully digitized and store their images at the central hospital.
Those images can be accessed directly from the physician’s desktop through an
EPR interface. In some areas small regional hospitals have a combined image
archive and distribution system together with the primary health care centres.
The boarder line between teleradiology and image distribution through a
regional archive is gradually vanishing with certain services. In the current survey,
all the methods used for a regional image transfer service were investigated. For a
regional service, the basic assumption was that a hospital should have a local
PACS installed. Then, the technical infrastructure behind the implementation of
regional image distribution could differ. In some areas, images are viewed
through a regional reference database. In other areas there is a dedicated common
regional radiological database (“regional PACS”). A third solution is to view
images through regional access to an EPR archive, which also contains images.
The EPR is the most important tool for health professionals in acquiring and
documenting information about patient care. During the year 2005 study in
Finland, 95.6% of the primary health care centres and 95% of the hospital
districts used EPR as their primary tool for patient data. Compared to the year
2003, there is very strong progress in secondary care both in terms of coverage in
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various medical specialities and in the intensity of use. Because of the complexity
of secondary care (hospital) medical records, the coverage aspect is an important
indicator of EPR penetration there. Among primary health care centres, the
proportion of health centres using EPR was already 93.6% in 2003. The most
recent survey update in this series shows that 100% of Finnish hospital districts
and practically 100% of health centres now have EPR in use (Hämäläinen et al.
2009). Knowing all this, one can say that the penetration of EPR is no longer a
measure of ICT usage in Finland and that new indicators need to be sought.
International comparison of eHealth status
When comparing the Finnish health care ICT situation internationally, Finland
belongs to the global leaders together with Denmark and Sweden, according to a
recent report of the Information Technology and Innovation Foundation (Castro
2009). According to the report, all of these there countries are definitely ahead of
the United States and most other countries in moving forward with their health
information technology systems. This is because these three countries have nearly
universal usage of electronic health records among primary care providers, high
rates of adoption of electronic health records in hospitals, widespread use of
health information technology applications, advanced telehealth programs and
portals that provide access to online information.
Similar high uptake of health ICT applications as in our study was also found
in a study of ICT usage among general practitioners in Europe made by the
research institute Empirica by assignment of the European Commission (Empirica
2008). They identified five eHealth frontrunner countries with the eHealth use
indicator scoreboard: Denmark, the Netherlands, Finland, Sweden and the UK. Of
these, Finland was the only country where all the primary care physicians used
computers (and thus EPR) during their patient consultations.
New indicators and challenges of eHealth implementation
One new indicator is the exchange of information between health care institutions,
mostly between primary and specialized health care. In Finland, regional
exchange of information has been possible because of the high usage of EPR
systems within institutions. Regional exchange of radiological and laboratory data
has been one of the first applications, but today eReferrals and eDischarge letters
directly from EPR to EPR are on the increase. All these contribute to the seamless
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service systems of the patient. The popularity of regional data exchange has
resulted in four different widely used data exchange systems. With the patient’s
consent, the physician has instant access to previous patient data from other
institutions through a secure connection.
The exchange of electronic patient information between providers of health
services necessitates the use of networks with high data security, which can be
actualized through different kinds of intranet solutions or secure Internet
connections. This data exchange is increasing rapidly in Finland. This is because
digital data depositories in individual health care institutions are in active clinical
use, and protected data connections enable the communication of electronic
patient information.
Electronic prescription has been mentioned as an important indicator of
health care ICT maturity. In Finland, a national e-Prescribing pilot-project was
launched in 2002. The pilot-project ran from 2004 to 2006. The system was tested
in two hospital districts and a few health care centres. In 2007 a new law was
issued (L 61/2007) where Finland opted for a system based on a national
prescription database. In the pilot-project system, a doctor creates a prescription
with a legacy system, signs it with a strong electronic signature, and sends the
secured message to the national prescriptions database. The patient goes to a
pharmacy where the pharmacist accesses the database with the pharmacy’s system.
The pharmacist makes the required changes and marks the dispensing information
on the electronic prescription, signs the markings with a personal smart card, and
saves the markings to the prescription in the database and then delivers the
medication to the patient. The clinical use of electronic prescription in Finland
started in May 2010 in the city of Turku (STM 2010b).
Once the backbone for electronic management of patient data in Finland is
ready, the next major challenge is the construction and implementation of the
National EPR Archive. The task is not a minor one. The stage is already set by the
law on electronic management of patient information in social and health care (L
159/2007), which defines one secure national archive for permanent archiving of
standardized medical data. Finland has taken a bold initiative and is now building
a centralized, truly national solution. There are changes that need to be made, not
only in technology but also in ways of conducting daily tasks in health care.
According to the present law, the local systems should be connected to the archive
by April 2011, but in practice a transition period of several years is needed. The
greatest challenges may occur in communication between local and regional
systems and the national archive. This might require major changes in the current
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software being used in hospital districts and health care centres. The goal is
increased access to electronic personal of health records, both by the physician
and the patient.
Update on national health care information architecture
It has been a great challenge to implement the previously mentioned current
legislation of electronic management of patient information (L 159/2007). That is
why the Finnish government issued in autumn 2010 a new proposal for a
modified act that would enable the national medical record archive to serve
patient care better and make it easier for health care personal to have access to the
required health information. It is also proposed that the implementation timetable
should be adjusted. (HE 176/2010, STM 2010a.)
According to the proposal, the medical record archive (eArchive) will be
constructed stepwise in several phases. The contents will be further regulated by a
decree of the Ministry of Social Welfare and Health. According to the current
document, the first phase includes the so-called principal data, which contain
medical narrative texts, nursing summary information, risk information,
pharmaceuticals, laboratory results, radiological requests and reports as well as
electronic referral and discharge letter contents. (STM 2009, KanTa 2010, STM
2010a.)
Concerning medical imaging, it is important to note that initially only textual
information (requests and reports) contained in the main patient record system
will be archived. If the information is residing only in external systems (RIS), it is
not obligatory to store it in the national archive.
Medical images are not included in the first phase of archived material, but
their turn will come in the next phase. As of autumn 2010 the enterprise
architecture will be investigated and a proper solution will be suggested according
to an expert consultation. The task will probably include discussion of whether
images should also be stored at a single storage site, or whether regional storages
should also have a role and what the relationships will be between them. At the
same time, the processes concerned and therefore functional data architecture will
be investigated. The extra time will give an opportunity to learn more about
international experiences in this field.
At the same time, the method of obtaining patient’s consent for delivery of
electronic material from the national archive is made easier and more flexible.
Patients can in the future provide access to their information to all professionals
96
involved in their care, even in different institutions. The authorization is valid
until further notice, but patients can always cancel it. Of course, patients can
prevent the delivery of information that is too sensitive (opt-out principle). While
patients can use secure web access to view their most important health data
(eView) they can in the future use the same tool to manage their consent
(eConsent). (HE 176/2010.)
The timetable will be adjusted according to current reality. According to the
government proposal, all public health care organisations should have the first
phase finished by 9/2014, and the private sector should follow by 9/2015. This
means that there will be an extension of three to four and a half years compared to
present regulations. (HE 176/2010.)
Finally, more resources will be devoted to accomplishing the task. The
changes include shifting operational steering of national health information
system development and implementation from the Ministry to the National
Institute for Health and Welfare. (HE 176/2010.)
6.7
General discussion – from teleradiology to eHealth and beyond
During this study, technical platforms for teleradiology services were designed
and built for a regional service setting, for international communication settings
and for various mobile usage settings. Of these, no mobile smartphone combined
teleradiology and EPR terminal was found in the medical literature before this
study, and the international teleradiology connection using the Internet was also
one of the early experiments in this area. Their evaluation consisted of the
assessment of technical feasibility and diagnostic accuracy. Work practice issues
with teleradiology were also studied in the early stage of this discipline, and
finally, the distribution of teleradiology in the Finnish telemedicine and eHealth
context was investigated in a nationwide comprehensive survey targeting health
care institutions.
One of the strengths of the study was that the concepts developed in this
study were taken into clinical usage, or resulted in better system developments.
The joint lessons learned from the regional low-end teleradiology study and the
work practice study influenced the development of teleradiology scanners and
workstation software. Finally, mobile smartphone teleradiology consultation has
now been in clinical use at Oulu University hospital for 10 years.
From a technical point of view, this study showed that common consumer
technology in personal computers and communication networks is good enough
97
for medical purposes if performance aspects are discussed. Rosset et al. (2005)
and Ratib et al. (2009) have made observations on the same topic. Of course,
regulations and reliability requirements mean that medical device certification is
needed for those implementations that are finally taken into permanent patient
care. However, this general development has decreased the price of medical
technology; especially powerful computers for medical image processing are now
available at affordable prices.
The value of standardization cannot be overestimated. During the time course
of this study the DICOM standard was gradually becoming implemented in all
areas of teleradiology, making data compatibility an easier task. However, in
practical workflow issues more specific definitions are needed, and hopefully IHE
profiles will be used more for teleradiology, too. In the Western Health Region in
Norway, they have been able to connect numerous RIS/PACS solutions from
different public and private institutions using IHE radiological cross enterprise
document sharing definitions (Stoerkson & Aslaksen 2010). Another set of de
facto standards that have simplified data communication have been the Internet
protocols, which have made it easier to design data transfer tasks. In Swedish
Västra Götaland region (VGR) they have been able to develop a joint
teleworkspace which is integrated to the various RIS and PACS systems with
networked tools and graphical user interfaces (Lundberg et al. 2010). According
to the authors, the need for teleradiology as a service provided "by somebody" has
disappeared in VGR; today it is a shared service embedded in the innovative
radiology information infrastructure.
In this investigation, data compression was used a lot after its usefulness was
initially assured. Data compression is still necessary for teleradiology because of
the narrow bandwidths used especially in mobile or home connections. Actually,
successful use of data compression has been an enabling factor for new frontiers.
Large datasets in cross-sectional imaging can also be one reason to use data
compression. Fortunately, in literature it has been shown that diagnostic quality of
the images is not compromised by moderate compression levels, not even lossy
compression in the magnitude of 1:10 to 1:25. This naturally depends of image
type and size and in Germany they have published recommendation to use a
modest lossy compression in the magnitude of 1:5 to 1:15 depending on the target
modality (Loose et al. 2009).
The Internet provided a pathway and model for international teleradiology
consultations. This investigation covered the most typical user case, i.e. the need
of expert consultation for rare cases. It is worthwhile to notice that these
98
international consultations can be arranged in an easy and affordable manner.
Because data security is an issue, it is important to note that today there are ways
of setting up secure private connections over public networks. International
teleconsultations, however, have certain aspects that go beyond the technical ones.
The discussion of medical competence required and moreover, the discussion of
whether radiological image interpretation is merely “image reading” or highquality medical specialist consultation is an ongoing debate.
Recent advances in medical ICT usage have taken electronic patient records
to the level where more tight integration between imaging systems and HIS can
be predicted. Finland is one of the countries where EPRs have reached in practice
100% coverage and where picture archiving and communications systems are
used comprehensively in health care. This study has revealed important new
indicators, such as interorganizational data exchange, that can be used for
benchmarking health care ICT services. It this setting regional image distribution
and teleradiology have an increasing role as one of the eHealth services.
Most of the technical challenges of teleradiology are solved little by little as
the general digitalization of the imaging process and patient records progresses.
Solutions are also gradually being found for a common digital working
environment and eHealth-related workpractice issues in the most common
teleradiology settings. However, work practices should be carefully adjusted in
every new type of service setting. In its essence, teleradiology is a matter of
conducting computer-assisted and remote co-operative work, either within the
teleradiology work chain itself or in the longer medical work-up between patients,
practicing physicians and teleradiology consultants. With increasing possibilities
of implementing workload off-shoring and even international teleradiology,
medical quality of the services and issues related to legal aspects, such as liability
issues and patient’s consent will became more important. For international
teleradiology, the issue of different languages and medical tradition remains a
future challenge. The major development steps and driving forces for
teleradiology have been discussed in table 8.
99
Table 8. The major development steps in teleradiology related to enabling factors in
general ICT, medical ICT and the interests of various stakeholders.
Decade Achievements
Enabling factors
Acting forces
1900
First ideas
Telephone, telegram, radio
Individuals
1920
First experiments
Telegraphs, image facsimiles
Individuals
1950
Clinical videoteleradiology
Television, video cable
Individuals, hospitals
networks
1980
Commercial camera-on-stick
Affordable video cameras,
Individuals, hospitals,
devices, early computer-based
modems, first digital imaging
research institutions,
systems
modalities, computer
commercial enterprises
workstations
1990
Commercial high-end systems,
PC revolution, PACS and digital Reseach institutions,
advent of PC-based teleradiology,
imaging, standardization
clinical operation, point-to-point-
(DICOM), digital data networks, enterprises
hospitals, commercial
services, international experiments
the Internet
Teleradiology-PACS integration,
Acceptance of DICOM
Commercial enterprises,
teleradiology service providers,
standard, large scale PACS,
health care providers,
mobile systems development,
fast data networks, mobile
research institutions
international pilots
networking and computing,
2010
Practice of remote image reading
Integration of PACS-RIS-HIS
Governments and other
and
and distribution (“virtual hospital”),
with IHE profiles, eHealth
public stakeholders,
promotion, ubiquitous
health care providers,
2000
affordable data security
beyond workload off-shoring, to-the-point
mobile distribution, service quality
computing, government interest commercial enterprises
management
Teleradiology as a concept has already moved on from its technical background.
It can be used to denote a service within public health care, e.g. between primary
care and secondary care hospitals, or it can be seen as an external service, where
part of the work has been outsourced to external (private) providers. There are
already services like mammography screening which mostly rely on teleradiology
in image interpretation.
One could say that teleradiology has become a fully-fledged tool in eHealth
service delivery. Medical imaging results can be distributed, and so can image
interpretation tasks. Ubiquitous imaging is already here.
100
7
1.
2.
3.
4.
5.
6.
Summary and Conclusions
This investigation suggested that a good image quality can be restored in the
transmission of images with the low-end personal computer and a commonly
available commercial software configuration tested. This could make it
possible to build teleradiology links for special purposes at a lower cost
compared to the commercial high-end systems. There were limitations in
technical quality and manoeuvrability, however.
Teleradiology between two institutions changed the image interpretation
work processes and revealed hidden aspects of work practice that are not
normally noticed. Especially articulation work that supports the key tasks is
now mostly conducted at the receiving site. The receiving site is also heavily
dependent on the decisions made at the sending site. The radiologists have to
rely on less information than in the case of on-site image reading.
Communication of relevant information is essential in both directions.
This study showed that with careful planning the Internet can provide a
feasible transmission channel for international teleradiology consultations
between hospital networks. Even though the Internet is readily available,
there are shortcomings in its speed and safety. Therefore, further investigation
and development is needed, especially in the field of data safety.
According to this study, a radiologist can carry his workstation for CT
interpretation as a laptop computer in his briefcase. The main limitation was
the speed of data transfer, but this situation will improve steadily with
technological developments. Ubiquitous communication technology enables
a more efficient use of expertise. However, the new tools require training in
order to be utilized to full extent.
Smartphones offer a new tool to gain access to patient information outside the
hospital. Despite the small screen, the image quality in the terminals is
sufficient for clinical decision-making, and even with low bandwidth the data
transfer speed is tolerable. With the progress in technology, these devices
seem to become more useful.
Teleradiology has become an integrated part of eHealth and its distribution
together with PACS distribution has steadily increased in Finland during the
2000s. From primary health care users’ point of view it seems to be irrelevant
whether the image transfer services are called teleradiology or regional
imaging study results delivery.
101
102
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Original publications
This thesis is based on the following original articles, which are referred to in the
text by their Roman numerals.
I
II
III
IV
V
VI
VII
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Digital Teleradiology. Eur J Radiol 19: 226–231.
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changes in work practices. Comput Methods Programs Biomed 57(1–2): 69–78.
Reponen J, Palsson T, Kjartansson O, Ilkko E, Störmer J, Päivänsalo M, Pyhtinen J,
Laitinen J, Eiriksson A & Brekkan A (1995) Nordic Telemedicine Consultation
Network Using Internet. Proceedings of CAR ´95 Computer Assisted Radiology and
Surgery. Berlin, Springer Verlag: 723–728.
Reponen J, Ilkko E, Jyrkinen L, Karhula V, Tervonen O, Laitinen J, Leisti E-L,
Koivula A & Suramo I (1998) Wireless radiological consultation with portable
computers. J Telemed Telecare 4: 201–205.
Reponen J, Ilkko E, Jyrkinen L, Tervonen O, Niinimaki J, Karhula V & Koivula A
(2000) Initial experience with a wireless personal digital assistant as a teleradiology
terminal for reporting emergency computerized tomography scans. J Telemed
Telecare 6(1): 45–9.
Reponen J, Niinimäki J, Kumpulainen T, Ilkko E, Karttunen A & Jartti P (2005)
Mobile teleradiology with smartphone terminals as a part of a multimedia electronic
patient record. Int Congr Ser 1281: 916–921.
Reponen J, Winblad I & Hämäläinen P (2008) Current status of national eHealth and
telemedicine development in Finland. Stud Health Technol Inform 134: 199–208.
Reprinted with permission from Elsevier (I, II, VI), Springer (III), Royal Society
of Medicine (RSM) press (IV, V) and IOS press (VII).
Original publications are not included in the electronic version of the thesis.
119
120
ACTA UNIVERSITATIS OULUENSIS
SERIES D MEDICA
1063. Gäddnäs, Fiia (2010) Insights into healing response in severe sepsis from a
connective tissue perspective : a longitudinal case-control study on wound
healing, collagen synthesis and degradation, and matrix metalloproteinases in
patients with severe sepsis
1064. Alaräisänen, Antti (2010) Risk factors and pathways leading to suicide with special
focus in schizophrenia : the Northern Finland 1966 Birth Cohort Study
1065. Oja, Paula (2010) Significance of customer feedback : an analysis of customer
feedback data in a university hospital laboratory
1066. Mustonen, Erja (2010) The expression of novel, load-induced extracellular matrix
modulating factors in cardiac remodeling
1067. Mäkinen, Johanna (2010) Systematic search and evaluation of published scientific
research : implications for schizophrenia research
1068. Jartti, Pekka (2010) Computed tomography in subarachnoid haemorrhage :
studies on aneurysm localization, hydrocephalus and early rebleeding
1069. Rantala, Aino (2010) Susceptibility to respiratory tract infections in young men:
the role of inflammation, mannose-binding lectin, interleukin-6 and their genetic
polymorphisms
1070. Tanskanen, Päivikki (2010) Brain MRI in subjects with schizophrenia and in adults
born prematurely : the Northern Finland 1966 Birth Cohort Study
1071. Abass, Khaled M. (2010) Metabolism and interactions of pesticides in human and
animal in vitro hepatic models
1072. Luukkonen, Anu-Helmi (2010) Bullying behaviour in relation to psychiatric
disorders, suicidality and criminal offences : a study of under-age adolescent
inpatients in Northern Finland
1073. Ahola, Riikka (2010) Measurement of bone exercise : osteogenic features of
loading
1074. Krüger, Johanna (2010) Molecular genetics of early-onset Alzheimer's disease and
frontotemporal lobar degeneration
1075. Kinnunen, Urpo (2010) Blood culture findings during neutropenia in adult
patients with acute myeloid leukaemia : the influence of the phase of the disease,
chemotherapy and the blood culture systems
1076. Saarela, Ville (2010) Stereometric parameters of the Heidelberg Retina
Tomograph in the follow-up of glaucoma
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OULU 2010
U N I V E R S I T Y O F O U L U P. O. B . 7 5 0 0 F I - 9 0 0 1 4 U N I V E R S I T Y O F O U L U F I N L A N D
U N I V E R S I TAT I S
S E R I E S
SCIENTIAE RERUM NATURALIUM
Professor Mikko Siponen
HUMANIORA
University Lecturer Elise Kärkkäinen
TECHNICA
Professor Hannu Heusala
MEDICA
Professor Olli Vuolteenaho
SCIENTIAE RERUM SOCIALIUM
ACTA
TELERADIOLOGY—
CHANGING RADIOLOGICAL
SERVICE PROCESSES FROM
LOCAL TO REGIONAL,
INTERNATIONAL AND
MOBILE ENVIRONMENT
Senior Researcher Eila Estola
SCRIPTA ACADEMICA
Information officer Tiina Pistokoski
OECONOMICA
University Lecturer Seppo Eriksson
EDITOR IN CHIEF
Professor Olli Vuolteenaho
PUBLICATIONS EDITOR
Publications Editor Kirsti Nurkkala
ISBN 978-951-42-6371-2 (Paperback)
ISBN 978-951-42-6372-9 (PDF)
ISSN 0355-3221 (Print)
ISSN 1796-2234 (Online)
U N I V E R S I T AT I S O U L U E N S I S
Jarmo Reponen
E D I T O R S
Jarmo Reponen
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O U L U E N S I S
ACTA
A C TA
D 1077
UNIVERSITY OF OULU,
FACULTY OF MEDICINE,
INSTITUTE OF DIAGNOSTICS,
DEPARTMENT OF DIAGNOSTIC RADIOLOGY;
UNIVERSITY OF OULU,
FACULTY OF MEDICINE,
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