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IMIIT’99
27-29 August 99
Kuala Lumpur
A Tutorial on
Standards and Infrastructure
in Teleradiology
by
Ng Kwan-Hoong, PhD
UMMC
Ong Hang-See, PhD
UNITEN
B J J Abdullah, FRCR
UMMC
Standards & Infrastructure in Teleradiology
Objectives
Appropriate utilization of teleradiology can improve
access to quality radiological interpretation and
thus significantly improve patient care.
 To introduce the American College of Radiology
(ACR) standards that should serve as a model for
Malaysian health care providers. Relevant issues and
possible solutions will also be discussed.
 To introduce the basic of hospital data
communication infrastructure. Data communication
devices, protocols and standard will be presented. A
sample list of solution providers will be given with
some suggestions on the selection.
Standards & Infrastructure in Teleradiology
Basis of the Malaysian
Teleradiology Standards
being drafted by the
Malaysian Radiological Society
Standards & Infrastructure in Teleradiology
Standards in Teleradiology
CONTENT
1.
2.
3.
4.
5.
6.
What is Teleradiology?
What are the Functions of Teleradiology?
When is Teleradiology not appropriate?
Goals of Teleradiology
Qualifications of Personnel
Equipment Specifications
Standards & Infrastructure in Teleradiology
Infrastructure in Teleradiology
CONTENT
1. Introduction
2.
3.
4.
5.
6.
Overview of Data Communication
Local Area Network
Wide Area Network
Emerging Technology
Solution Providers
Standards & Infrastructure in Teleradiology
The resource material for this tutorial are:
1. ACR Standard for Teleradiology
Revised 1998 (Res. 35)
2. Andrew S. Tanenbaum, "Computer Network", 3rd ed.
Prentice- Hall, Upper Saddle River, NJ, USA.
ISBN: 0-13- 394248-1
3. Networking 101
http://richardbruce.com/networking/
4. The impact of teleradiology in clinical practice
- a Malaysian perspective
B J J Abdullah, K H Ng, R Pathmanathan
Medical Journal of Malaysia, 54(2), 169-174, 1999
Standards & Infrastructure in Teleradiology
What is Teleradiology?
Teleradiology is the electronic
transmission of radiological images
from one location to another for the
purposes of interpretation and/or
consultation.
Standards & Infrastructure in Teleradiology
What are the functions of
Teleradiology?
• May allow more timely interpretation of
radiological images and give greater
access to secondary consultations and
to improved continuing education.
• Users in different locations may
simultaneously view images.
• May improve access to radiological
interpretations and thus significantly
improve patient care.
Standards & Infrastructure in Teleradiology
When is Teleradiology not appropriate?
• If the available system does not provide images
of sufficient quality to perform the indicated task.
• When a system is used to produce the official
interpretation, there should not be a clinically
significant loss of spatial or contrast resolution
from image acquisition through transmission to
final image display.
• For transmission of images for display
use only, the image quality should be sufficient to
satisfy the needs of the clinical circumstance.
Standards & Infrastructure in Teleradiology
Goals of Teleradiology
1. Providing consultative and interpretative
radiological services in areas of need;
2. Making radiologic consultations available
in medical facilities without on-site
radiologic support;
3. Providing timely availability of
radiological images and radiological
image interpretation in emergent and
non-emergent clinical care areas;
Standards & Infrastructure in Teleradiology
Goals of Teleradiology/2
4. Facilitating radiological interpretations
in on-call situations;
5. Providing subspecialty radiological
support as needed;
6. Enhancing educational opportunities for
practicing radiologists;
Standards & Infrastructure in Teleradiology
Goals of Teleradiology/3
7. Promoting efficiency and quality
improvement;
8. Sending interpreted images to referring
providers;
9. Supporting telemedicine; and
10. Providing direct supervision of off-site
imaging studies.
Standards & Infrastructure in Teleradiology
QUALIFICATIONS OF
PERSONNEL
The radiological examination at the transmitting
site must be performed by qualified
personnel. In all cases this means a licensed
and/or registered radiographer. He/she must
be under the supervision of a qualified/
licensed radiologist or a physician.
It is desirable to have medical physicist and/or
image management specialist on site or as
consultants.
Standards & Infrastructure in Teleradiology
EQUIPMENT SPECIFICATIONS
• Vary depending on the individual
facility's needs but, in all cases, should
provide image quality and availability
appropriate to the clinical need.
Standards & Infrastructure in Teleradiology
EQUIPMENT SPECIFICATIONS
• Compliance with the ACR/NEMA Digital
Imaging and Communication in
Medicine Standard (DICOM) is strongly
recommended for all new equipment
acquisitions and consideration of
periodic upgrades incorporating the
expanding features of that standard
should be part of the ongoing
quality-control program.
Standards & Infrastructure in Teleradiology
EQUIPMENT SPECIFICATIONS
• Equipment guidelines cover two basic
categories of teleradiology when used
for rendering the official interpretation:
 small matrix size (e.g., CT, MR, US,
NM, digital fluorography, and digital
angiography) and
 large matrix size (e.g., CR and
digitized radiographic films).
Standards & Infrastructure in Teleradiology
EQUIPMENT SPECIFICATIONS
• Small matrix: A data set should provide
full-resolution data (typically 512 x 512
resolution at minimum 8-bit depth) for
processing, manipulation, and
subsequent display.
• Large matrix: A data set allowing a
minimum of 2.5 lp/mm spatial resolution
at minimum 10-bit depth should be
acquired.
Standards & Infrastructure in Teleradiology
EQUIPMENT SPECIFICATIONS
•
•
•
•
•
•
•
A. Acquisition or Digitization
B. Compression
C. Transmission
D. Display Capabilities
E. Archiving and Retrieval
F. Security
G. Reliability and Redundancy
Standards & Infrastructure in Teleradiology
A. Acquisition or Digitization
1. Direct image capture
• The image data set produced by the digital
modality both in terms of image matrix size
and pixel bit depth should be transferred to
the teleradiology system. It is recommended
that the DICOM standard be used.
• This is the most desirable mode of digital
image acquisition for primary diagnosis.
Standards & Infrastructure in Teleradiology
A. Acquisition or Digitization
2. Secondary image capture
• a. Small matrix images. Each image should be digitized to
a matrix size as large or larger than that of the original
image by the imaging modality. The images should be
digitized to a bit depth of 8 bits per pixel or greater. Film
digitization or video frame grab systems conforming to
these specifications are acceptable.
• b. Large matrix images. These images should be digitized
to a matrix size corresponding to 2.5 lp/mm or greater,
measured in the original detector plane. These images
should be digitized to a bit depth of 10 bits per pixel or
greater. Film digitizers will generally be required to
produce these digital images.
Standards & Infrastructure in Teleradiology
A. Acquisition or Digitization
3. General requirements
• At the time of acquisition (small or large matrix), the
system must include:
Annotation capabilities including patient name,
identification number, date and time of examination,
name of facility or institution of acquisition, type of
examination, patient or anatomic part orientation
(e.g., right, left, superior, inferior, etc.), amount and
method of data compression. The capability to record
a brief patient history is desirable.
Standards & Infrastructure in Teleradiology
B. Compression
• Data compression may be performed to
facilitate transmission and storage. Several
methods, including both reversible and
irreversible techniques may be used with no
reduction in clinically diagnostic image quality.
The types and ratios of compression used for
different imaging studies transmitted and
stored by the system should be selected and
periodically reviewed by the responsible
physician to ensure appropriate clinical image
quality.
Standards & Infrastructure in Teleradiology
C. Transmission
• The type and specifications of the
transmission devices used will be dictated by
the environment of the studies to be
transmitted. In all cases, for official
interpretation, the digital data received at the
receiving end of any transmission
must have no loss of clinically significant
information. The transmission system shall
have adequate error-checking capability.
Standards & Infrastructure in Teleradiology
D. Display Capabilities
• General: Display workstations used for official
interpretation and employed for small matrix
and large matrix systems should provide the
following characteristics:
1. Luminance of the gray-scale monitors should be at
least 50 foot-lamberts (538 lux);
2. Care should be taken to control the lighting in the
reading room to eliminate reflections in the monitor
and to lower the ambient lighting level as much as is
feasible.
Standards & Infrastructure in Teleradiology
D. Display Capabilities
3. Provide capability for selection of image sequence;
4. Capable of accurately associating the patient and
study demographic characterizations with the study
images;
5. Capable of window and level adjustment, if those
data are available;
6. Capable of pan functions and zoom (magnification)
function;
7. Capable of meeting guidelines for display of all
acquired data;
Standards & Infrastructure in Teleradiology
D. Display Capabilities
8. Capable of rotating or flipping the images, provided
correct labeling of patient orientation is preserved;
9. Capable of calculating and displaying accurate linear
measurements and pixel value determinations in
appropriate values for the modality (e.g., Hounsfield
units for CT images), if those data are available;
10. Capable of displaying prior image compression
ratio, processing, or cropping;
11. Elements of display that should be available include:
a. Matrix size;
b. Bit depth; and
c. Total number of images acquired in the study.
Standards & Infrastructure in Teleradiology
E. Archiving and Retrieval
If electronic archiving is to be employed, the
guidelines listed below should be followed:
1. Teleradiology systems should provide
storage capacity capable of complying with all
facility, state, and federal regulations
regarding medical record retention. Images
stored at either site should meet the
jurisdictional requirements of the transmitting
site.
Standards & Infrastructure in Teleradiology
E. Archiving and Retrieval
Images interpreted off-site need not be stored
at the receiving facility, provided they are
stored at the transmitting site. However, if the
images are retained at the receiving site, the
retention period of that jurisdiction must be
met as well. The policy on record
retention should be in writing.
Standards & Infrastructure in Teleradiology
E. Archiving and Retrieval
2. Each exam data file must have an accurate
corresponding patient and examination
database record, which includes patient
name, identification number, exam date, type
of examination, facility at which examination
was performed. It is desirable that space be
available for a brief clinical history.
3. Prior examinations should be retrievable from
archives in a time frame appropriate to the
clinical needs of the facility and medical staff.
Standards & Infrastructure in Teleradiology
E. Archiving and Retrieval
4. Each facility should have policies and
procedures for archiving and storage of digital
image data equivalent to the policies that
currently exist for the protection of hard-copy
storage media to preserve imaging records.
Standards & Infrastructure in Teleradiology
F. Security
Teleradiology systems should provide network
and software security protocols to protect the
confidentiality of patients’ identification and
imaging data. There should be measures to
safeguard the data and to ensure data
integrity against intentional or unintentional
corruption of the data.
Standards & Infrastructure in Teleradiology
G. Reliability and Redundancy
Quality patient care depends on availability of
the teleradiology system. Written policies and
procedures should be in place to ensure
continuity of care at a level consistent
with those for hard-copy imaging studies and
medical records within a facility or institution.
This should include internal redundancy
systems, backup tele-communication links,
and a disaster plan.
Standards & Infrastructure in Teleradiology
The impact of teleradiology in clinical practice
- a Malaysian perspective
B J J Abdullah, K H Ng, R Pathmanathan
Medical Journal of Malaysia, 54(2), 169-174, 1999
Standards & Infrastructure in Teleradiology