Download How to Utilize an Open Source DICOM Viewer

INNOVATIVE IMAGING TECHNIQUES TO ENHANCE THE QUALITY OF YOUR PRACTICE
How to Utilize an Open Source DICOM Viewer
and Properly Transmit Diagnostic Images in Your
Practice
Kurt Selberg, MS, DVM, MS, DACVR*; and Jeremiah T. Easley, DVM, MS, DACVS
Author’s address: University of Georgia, Veterinary Biosciences and Diagnostic Imaging, 501 DW
Brooks Drive, Athens, GA 30602 (Selberg); and Colorado State University, 300 West Drake Road, Fort
Collins, CO 80523 (Easley); e-mail: [email protected]. *Corresponding and presenting
author. © 2014 AAEP.
1.
Introduction
The adoption of digital imaging has been swift and
recent. The greatest advantage of digital imaging
is the ability to manipulate contrast, zoom in on
areas of interest, make measurements, and transfer
them via the Internet for consultation. However,
for optimal benefit, this adoption requires more
technical “know how.” As such, the need for image
visualization and analysis has extended beyond the
light box. Software for digital imaging and communications in medicine (DICOM) image viewing is
often expensive, challenging to navigate, and limited in accessibility. Because of this, practitioners
often send and receive radiograph, ultrasound, computed tomography, or magnetic resonance as lossy
compressed images with .jpg or .jpeg (Joint Photographic Experts Group (JPEG)) file extensions for
consultation on cases. However, when a diagnostic
image is exported as a JPEG image important metadata and information in the DICOM header that
tells the detector system, the radiographic technique, institution obtaining the radiographs, compression levels, and a host of other information is
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stripped. Most importantly, the information of
scale is also stripped, so measuring lesions is not
reliable. Furthermore, JPEG images are difficult
to manipulate in a way to ensure that the reader is
able to properly evaluate the entire image. Therefore, it is important that practitioners realize the
advantage of reading and sharing DICOM images.
In order to share DICOM images, practitioners
must have access to simple, user-friendly, and free/
affordable DICOM imaging software and easy methods to transfer images to colleagues and specialists.
Osirixa is an open source Mac OSX-based image
processing application for DICOM image viewing.
It is free and downloadable software from the Internet. This user-friendly software will aid practitioners in not only evaluating their own images such as
radiographs and ultrasound, but it will allow them
to manipulate, illustrate, and prepare images and
even videos for presentations to clients and colleagues. Osirix is specifically designed to navigate
and visualize 2D and 3D images while at the same
time acting as a DICOM picture archiving and communication system (PACS) workstation (it can also
INNOVATIVE IMAGING TECHNIQUES TO ENHANCE THE QUALITY OF YOUR PRACTICE
Fig. 1. The database window of Osirix with a list of the patients. The bottom half of the window displays the thumbnail previews.
Along the right, there is a list of current and prior studies displayed.
handle 4D and 5D, but that is outside the scope of
this discussion). Additionally, this program will
easily transmit images via DICOM transfer or export the DICOM images for transfer via free file
sharing programs. Learning to use software such
as Osirix will improve practitioners’ ability to evaluate medical images, consult with other professionals
on cases, and even provide increased understanding
of cases to clients. This article aims to provide
practitioners with an overview of the many capabilities of Osirix, an open source DICOM imaging software and file-sharing options.1
2.
Materials and Methods
Software
An open source stand-alone application has been
developed that serves as a DICOM viewer and
PACS. Osirix can be downloaded at www.Osirixviewer.com to run on the latest version of OsX..
There are alternatives for the Windows users such
as Ginkgo CADx,b however this “how to” will be
confined to Osirix and free file-sharing software.
There are numerous download options to choose
from, including the free 32-bit version, a paid 64-bit
version, a paid FDA approved 64-bit version for
medical usage, and a paid version for iPad and
iPhone users. Unless you are a radiologist or performing advanced imaging studies with very large
volume sets, the free 32-bit version should suffice in
most scenarios.
The Osirix program offers all the basic image manipulation functions of zoom, pan, contrast adjustment, image orientation, and measure, as well as
allowing annotation and database organization by
client or diagnosis. It also has the ability to hang
multiple relevant prior exams. Additional advanced functions that can be performed include multiplanar
reconstructions,
convolution
filters,
variable slice thickness adjustments, volume rendering, minimum and maximum intensity projections, and surface rendering.
There are several free file-sharing programs commercially available. Dropbox, Google Drive, and
Microsoft Onedrive are the most notable. Only
Dropbox will be explored in depth in this “how to.”2
A Dropbox account can be created and the software
can be downloaded at www.dropbox.com. This is
available for Windows, OsX, as well as mobile versions. Dropbox is an installable program or webbased program that syncs images on a personal
computer as well as a remote server, also known as
the cloud. This program allows folders and files to
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INNOVATIVE IMAGING TECHNIQUES TO ENHANCE THE QUALITY OF YOUR PRACTICE
Table 1.
Fig. 2. This is the diagnostic window with a sagittal plane
magnetic resonance image of the foot. The tool bar is located at
the top of the screen with common tools such as pan, zoom, and
window on the left side. Osirix automatically detects the number of displays and uses all available real estate to display the
study. While the cursor is over the image, a right mouse click
will also give options to change the mouse function. By default,
left click is window/level, right click is zoom, and scroll is performed by dragging a finger forward and back.
be shared using links to the file storage site rather
than e-mailing the entire files, which circumvents
e-mail server limits on attachment file size.
3.
Results
Both authors use Osirix almost exclusively to view
10 to 30 studies daily comprised of both clinical as
well as research cases in an academic setting. One
author uses Osirix as a PACS and web server as well
as a DICOM viewer for the purposes of teleradiology.
The study modalities are radiographs, ultrasound,
nuclear medicine, magnetic resonance imaging, and
computed tomography. Additionally, photographs
or videos of patients included in prepurchase exams
may be imported and reviewed.
The database window shows the list of patients
(Fig. 1). From this window, there are a variety of
options for the selected patient. Double clicking on
the patient will open the image viewer (Fig. 2).
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List of Hot Key Actions in Osirix
Action
Key
Default window width and window level
Flip vertical
Flip horizontal
Zoom
Pan/move
Rotate
Measure length
Measure angle
Text
Arrow
⬃
V
H
Z
M
I
L
A
T
Q
Once the viewer is open, there is a customizable tool
bar with icons and descriptive words for the icons
along the top of the screen. The icons represent
tools to manipulate the images. The most common
tools used during review are the pan, zoom, and
contrast. However, there are a variety of tools that
are underutilized by practitioners, including arrow
and text tools to annotate images. The default tool
for the left click on the mouse is contrast. By default, right click (if you are using a single button
mouse or touch pad, clicking and simultaneously
holding down the control key is the same as a right
click) and hold will allow the user to zoom centered
on where the pointer is. The user can change the
left click tool by clicking on the icons in the toolbar
or right clicking and choosing. You can use the
keyboard to reduce the number of mouse clicks.
For example, holding down the option key with the
left mouse click causes the curser/pointer to become
the pan tool. When released, it returns to contrast.
Using hot keys also may increase productivity
(Table 1).
Osirix also has built in capabilities to display the
current and relevant prior studies. If connected to
your home or remote back up server, it will automatically check to see if there are additional studies for
the current patient.
Osirix has robust capabilities to reconstruct surface renderings and cut away specific bones and soft
tissue in cross sectional imaging. This capability is
used by the authors weekly, if not daily, for surgical
planning and teaching.
Right clicking on a study in the database window
will give you several options, including export.
A variety of options for exporting images are available. Exporting as DICOM file(s) is the appropriate choice for transmitting radiographs through filesharing applications. Once this is selected, a
window appears asking where to save the resulting
file (Fig. 3). If you have already set up Dropbox,
this folder will appear in the favorites bar in the
finder window. There are also several options to
check in the export window. The defaults settings
are correct, which are checked boxes next to add
DICOMDIR, hierarchical folder tree, don’t modify
the files for compression, and save as ZIP. The
INNOVATIVE IMAGING TECHNIQUES TO ENHANCE THE QUALITY OF YOUR PRACTICE
Fig. 3. Export window. By right clicking on the patient study in the database, an option for export is displayed.
options for saving the study. The displayed settings are the most helpful.
authors recommend compressing (zipping) the diagnostic images (Fig. 3). This can be password protected if needed. This may be done by adding the
desired password under the zip option. This also
acts as a single file rather than multiple and is often
easier to manage. Once in the Dropbox folder, the
integration of the program allows a link to be generated (Fig. 4) for the file by right clicking on the file
and selecting “share link.” This link is then pasted
into an electronic mail message and sent to a selected recipient.
4.
Discussion
Osirix image viewing software and Dropbox file
sharing software have revolutionized consultation
capabilities within the medical field. Positive collaboration and consultations between practitioners
and specialists is vital to the overall success of the
patient. With the increased utilization and improved access to advanced imaging in equine veterinary medicine, this collaboration becomes even
more important. Advanced imaging modalities
such as computed tomography and magnetic resonance imaging are growing rapidly due to high
The window gives
sensitivity and specificity for pathologic change.
However, the success cannot be achieved without
accurate evaluation of the images produced by these
modalities. Equally important is the ability of the
image evaluator to describe and illustrate image
findings in order to ensure an appropriate clinical
therapeutic plan.
As previously mentioned, similar products as an
alternative to Osirix for Windows-based users are
available. One of the easier programs to navigate
is Ginkgo CADx (http://ginkgo-cadx.com/en/downloads/). This also comes in a variety of download
options for free with limited support to a paid version that offers professional support. The program
is feature-rich with basic abilities similar to Osirix
such as pan, zoom, magnify, measure, and DICOM
send features.
The minimum system requirements for Osirix are
summarized (Appendix 1). Similar recommendations should be employed on a Windows-based computer. The advantage of the 64-bit system is its use
of system memory for performing tasks. As previously outlined, in large data sets such as cross sectional imaging, more memory must be allocated to
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INNOVATIVE IMAGING TECHNIQUES TO ENHANCE THE QUALITY OF YOUR PRACTICE
is best in a dimly lit room. This increases the perceived contrast of the image and reduces glare on
the screen.
The veterinarian often is encountered with clients
wanting the images of the patient. Similar to other
DICOM viewers, Osirix allows for the studies to be
packaged with a “lite” version of the Osirix viewer
and a Java-based DICOM viewer. In this regard,
the packaged viewer is capable of displaying the
images on both Apple and Microsoft operating systems. The Java based viewer comes with pan,
zoom, window width, and level capabilities.
In summary, it is important that practitioners
have an understanding of the advantages to DICOM
image viewing and file-sharing. Osirix is easy to
learn and can quickly become indispensible software
to any practitioner utilizing digital imaging equipment in their practice. As such, Osirix can help
bridge the gap between practitioners and specialists,
which can lead to advancements in diagnostic capabilities, increased disease understanding, successful
therapeutic planning, and ultimately improved clinical outcomes and client satisfaction.
Acknowledgments
Conflict of Interest
The Authors declare no conflicts of interest.
Appendix 1
The hardware recommendations for Osirix are outlined:
●
●
Fig. 4. This is the right click option of the exported study saved
in the Dropbox folder. By selecting the “share Dropbox link” a
link is saved to the computer’s clipboard and is able to be pasted
to an electronic message.
the program. In cases of radiographic and ultrasound review, the 32-bit Osirix program will perform well.
Recommendations for monitors to review cases on
have been set by the American College of Radiology.
Veterinary Radiology also uses the guideline that a
3 MP, medical grade, 350 cd/m2 monitor be employed. Newer liquid crystal display monitors often exceed this recommendation. The authors
currently use Apple 27 in. displays with specifications of 3.7 MP, 375 cd/m2, and a contrast ratio of
1000:1. It should also be noted that viewing images
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MacOS X 10.8 or higher
Intel processor
For best performance:
●
2– 4 GB of RAM for Radiographic image review
(DX and CR)
● 6 GB of RAM if you plan to open more than 800
images (CT and MRI, PET-CT)
● 8 GB of RAM for more than 1500 images
(multi-slice CT and PET-CT) with OsiriX-64
bit
● 12 GB of RAM for more than 3000 images
(cardiac or functional imaging) with OsiriX-64
bit
References and Footnotes
1. http://www.osirix-viewer.com/AboutOsiriX.html
2. https://www.dropbox.com/
a
b
Osirix, Pixmeo SARL, Bernex, Switzerland,
Ginkgo CADx, MetaEmotion S.L, Valladolid, Spain.