AJR 2004; 183:535-537
© American Roentgen Ray Society
MyFreePACS: A Free Web-Based Radiology Image Storage and Viewing Tool
David de Regt1 and
Ed Weinberger2,3
1 Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202-8199.
2 Department of Radiology, Children's Hospital and Regional Medical Center,
5C-1, 4800 Sand Point Way NE, Seattle, WA 98195.
3 Department of Radiology, University of Washington School of Medicine, Box
357115, 1959 NE Pacific St., Seattle, WA 98195.
Received November 25, 2003;
accepted after revision March 12, 2004.
Address correspondence to E. Weinberger
(vankleek{at}u.washington.edu).
Partially supported by the Clifford A. Garl Radiology and Medical Imaging
Education Fund.
Abstract
OBJECTIVE. We developed an easy-to-use method for central storage
and subsequent viewing of radiology images for use on any PC equipped with
Internet Explorer.
CONCLUSION. We developed MyFreePACS, a program that uses a DICOM
server to receive and store images and transmit them over the Web to the
MyFreePACS Web client. The MyFreePACS Web client is a Web page that uses an
ActiveX control for viewing and manipulating images. The client contains many
of the tools found in modern image viewing stations including 3D localization
and multiplanar reformation. The system is built entirely with free components
and is freely available for download and installation from the Web at
www.myfreepacs.com.
Introduction
We had not yet purchased a PACS system and were noticing the increasing
size of CT and MR data sets. Our radiologists wanted a simple method to view
images from CT, MRI, and other techniques. We began looking for a base set of
freely available tools that we could enhance to create a miniature PACS
system. A prime component of our solution is the Mallinckrodt archive server.
This tool is one of the components of the Mallinckrodt Central Test Node DICOM
software-testing suite
(wuerlim.wustl.edu/DICOM/ctn.html).
Although this DICOM server is highly capable, it requires considerable
computer sophistication to manage. In addition, we could not find any suitable
freely available client software to use as the image viewer. We therefore
decided to create a Web-based administration system for the DICOM server as
well as secure image-viewing system.
Materials and Methods
Our solution has a number of components. We found that the tools that we
started with allow our solution to be installed on both Windows (Microsoft)
and Linux servers. The DICOM server is the Mallinckrodt archive server. The
server writes to a structured query language (SQL) database contained in
either MySQL
(www.mysql.com/)
MySQL AB or SQL Server
(www.microsoft.com/sql/)
(Microsoft). The Web-based components are written in PHP: Hypertext
Preprocessor (PHP)
(www.php.net/).
The primary image-viewing tool is an ActiveX control written in C++ using
Visual Studio
(msdn.microsoft.com/vstudio/)
(Microsoft). Using a simple yet secure access system, any Windows-based
computer that can connect to the server over the Web can administer the server
and retrieve radiology images. Windows versions as old as Windows NT 4.0
(Microsoft) are supported clients. A client computer connects to the server
using Internet Explorer (Microsoft), and the user logs in.
After logging in, the user can search for and retrieve cases immediately.
All accesses to the system are logged for administrator viewing. Downloaded
cases are stored in a temporary cache. The cache is cleared when the user
closes the browser or navigates away from the MyFreePACS server. Cases can be
downloaded in an uncompressed format for fast retrieval over a local area
network or compressed using Zlib
(www.gzip.org/zlib/)
for sending over slower connections. The client also supports saving images in
JPEG format using the JPEG library
(developer.intel.com/software/products/perflib/ijl/index.htm)
(Intel).
MyFreePACS was developed and tested on both a Windows and a Linux server.
The initial development computer ran Linux version 7.3
(www.redhat.com/)
(Red Hat), which was later upgraded to version 9.0, and uses MySQL 4 for its
database. MyFreePACS works on either platform by changing a single line in the
configuration file. The Windows server has become our primary server. It runs
Windows 2000 Professional and uses the Microsoft SQL Server 2000 Desktop
Engine (MSDE) (Microsoft) for its SQL server, which is freely distributable
with applications written in Visual Studio.
The Server
Our goal was to create a system that would be easy for our department and
others to install and use. The install system was designed to make the
installation and setup of MyFreePACS as simple as possible. Installation and
basic setup of the server on a Windows computer should take no more than 15
min, not counting component download time. The Windows installation procedure
is fully explained at
www.myfreepacs.com.
The DICOM server is a fully DICOM-compliant server that supports storage and
retrieval of images from all DICOM-compliant platforms that we have tested.
The Web-based scripts have easy setup procedures for adding allowed DICOM
clients and for deleting series, studies, and patients from the database when
necessary. The scripts also show the size of the database to give
administrators warning when they are about to start losing old data. The DICOM
server deletes old cases in its database to make room for new cases when the
database is full.
The Client
The client program is designed for maximum usability by a computer novice,
but it provides powerful tools for more advanced users. The login system is
straightforward. After navigating to the MyFreePACS server Web page, the user
logs in using his or her username and password. The user is then presented
with the ability to either change the password or enter the image viewer.
Administrators are given the additional option of entering an administration
panel that includes features such as setting up valid DICOM nodes and
assigning user privileges. When the user enters the image viewer, a search
window is displayed. The user can search for studies by patient identification
number, patient name, date, or modality. The results are quickly returned in
an easy-to-navigate tree system containing the names of the patients returned
and all the studies and individual series in those studies
(Fig. 1). The user can then
download all studies for a given patient or can scroll down the patient tree
to download specific studies or series. All image accesses are logged to the
database, which can be viewed by an administrator at any time via the
administration panel. As soon as any images are retrieved, they are added to
the viewing window.
View larger version (79K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1. —Screen image shows sample results from patient search displayed in
search window. Total number of studies, series, and images are indicated to
right of each patient name that is returned in search window. Results of
search tree can be expanded to allow download of individual studies or
series.
|
|
New series are inserted into empty windows when they are downloaded. Window
contents can be easily changed by right clicking the window and selecting a
new series from the pop-up box. The number of windows can be easily changed
and can also be put into a linked array mode that is useful for viewing
sonographic images. Basic image manipulation features have been added such as
rotation, flipping, and inversion. The mouse-selectable toolbox consists of
scrolling, windowing or leveling, image moving or zooming, measurement (point
statistics, distances, and oval statistics), 3D localization
(Fig. 2), and multiplanar
reconstruction (Fig. 3). Automatic image linking by slice location and user-defined offset linking are
supported. Additional features include image position indicators, common CT
presets, image-filtering settings, overlay toggling, JPEG exporting with DICOM
fields removed, and display of DICOM fields.
View larger version (98K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2. —Screen image shows example of 3D localization tool. Placement of
small cursor on image in active (outlined) window immediately brings images in
all other windows to closest level with appearance of cursor over location
marked on active window.
|
|
Limitations
The MyFreePACS system has some limitations. As is true with most PACS
systems, the feature set of a release is static and is not configurable by the
end user. New features and bug fixes may be added in future releases.
MyFreePACS has also not been extensively tested. It has not been certified as
a primary viewing mechanism, so one is cautioned not to rely on MyFreePACS for
primary clinical interpretations. Finally, the completely free setup of
MyFreePACS under Windows uses MSDE, which has a database size limit of 2 GB.
This size limit is reached when the image collection is between 200 and 500
GB, depending on the modality types of images stored. If more storage is
needed, then the user can upgrade to SQL Server 2000 Standard (Microsoft),
which also requires using either Windows 2000 Server or Windows 2003 Server.
If one is running MyFreePACS on a Linux server, MySQL has no limit on database
size.
Advantages
For a low cost of setup—the cost of a basic desktop
computer—one gets a full DICOM server and viewing system. The DICOM
server can be used in a number of ways. We currently use the system to store
all CT and MRI studies obtained at our institution. This system allows
clinicians in our hospital easy access to previous studies from any hospital
computer, and the database is especially useful for clinical conferences
(e.g., tumor board) and teaching conferences. The JPEG export function makes
it easy to select images for teaching files or publication needs. We also
anticipate that the images stored can act as a ready repository of previous
studies for the day when we actually acquire a formal PACS system. We also
anticipate easy deployment for specialized individual use because MyFreePACS
can be set up on an individual laptop.
Conclusion
MyFreePACS has accomplished its goal of providing an easy-to-use tool for
radiologists to retrieve and manipulate images from any PC with Internet
Explorer that has access to the server. This system provides an integrated
viewing station and teleradiology solution at no cost and works on any
available PC. Finally, it provides long-term DICOM-compliant storage for DICOM
images for later integration into a PACS or simply for use in long-term
comparison.
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Abstract
Introduction
