CLEVELAND - Dealing with legacy films is a common problem when facilities move from film-based to filmless operation. The old films are needed to compare current images to prior studies, but there is rarely an elegant way to figure out which prior studies are stored in a radiology department’s PACS, and which are available only on film.
A group of researchers from the University of California, San Francisco has developed a homegrown solution to the problem, which they discussed in a SCAR presentation on Thursday. They’ve written a Web-based Java applet that enables radiologists to query both the hospital’s PACS and RIS networks to find out whether legacy films are available.
When UCSF installed its PACS several years ago, radiologists there discovered that the use of separate databases for RIS and PACS data made it hard to figure out whether prior studies were in the PACS, according to Wyatt Tellis, a third-year graduate student at UCSF’s Laboratory for Radiological Informatics. The PACS maintained a record of all digitally archived exams, but didn’t include any legacy films. The RIS had a record of all studies, digital and analog, but there was no way to tell which was which.
Radiologists were coping with the problem by either moving from their diagnostic workstation to a separate RIS terminal, or by opening a window into the RIS from the workstation. But the UCSF group thought it could devise a more elegant solution, Tellis said.
They decided to develop a database query tool based on relatively simple logic: If an exam was listed in the RIS database but did not have a record in the PACS, then it was probably a legacy film study. To make the tool easy to use, they developed a Web-based user interface that could be accessed by an icon on the radiologist’s desktop.
The tool is based on Java Server Pages (JSP) technology, and runs on an Apache Web server. Java-based DICOM and HL7 toolkits were developed in-house to provide connectivity to these data connectivity standards. Using Java was crucial because it allows the code that performs the DICOM and HL7 queries to be embedded in the Web page, eliminating the need for separate query and retrieve applications, Tellis said.
Clicking on the query tool’s icon on the diagnostic workstation launches a Web browser, which passes the patient’s ID and accession numbers to a JSP Web page. The page queries the PACS and RIS databases, and passes the results on to the radiologists in a color-coded format -- gray for PACS-based studies and white for those only available on film. Users can access the diagnostic report for the exam by clicking a button, which opens a separate JSP page that retrieves the report from the RIS.
Tellis reported good acceptance of the system since it was introduced at UCSF in December. In the first month of deployment, the page recorded 20 queries a day from display stations, with most of the queries coming from the thoracic and abdominal imaging sections -- the areas that historically have been more reliant on analog projection radiography.
UCSF believes the tool has helped radiologists work more efficiently and remain within the same clinical context when reading a patient’s images. "We think that this tool has successfully unified our hard- and soft-copy archives and is easing the transition to a digital department," Tellis said.
During a question-and-answer period that followed, an audience member described how his facility had approached the problem differently. When his group launched the PACS network, all of the pre-PACS RIS studies were backloaded into the PACS database. As a result, even though the images can't be accessed through the RIS, the group knows that if a PACS study shows up without images associated with it, it is probably a pre-PACS study.
Tellis said that UCSF’s PACS would flag a study without images as an error, and that having thousands of such entries in the PACS database could cause problems.
By Brian CaseyAuntMinnie.com staff writer
May 3, 2002
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