Multivendor digital mammo project makes mark in Germany

By Jonathan S. Batchelor

April 16, 2007 -- Digital mammography, using either computed radiography (CR) or digital radiography (DR), is rarely deployed as a standalone system. Most installations take place in a heterogeneous IT environment with different developers' RIS, PACS, and archive products interacting with the modality, which can present a host of integration concerns.

A group of information systems administrators in Germany recently faced the challenge of bringing CR mammography online and discovered that successfully assimilating the modality into the enterprise is not just an issue of interfacing the technology.

"Germany decided to establish a mammography screening program for women ages 50 to 69," said Claus-Peter Fröhlich. "Therefore, we had to search for a suitable solution for our state of Mecklenburg-Vorpommern."

Fröhlich, a clinical system administrator at the institute of diagnostic radiology and neuroradiology at Ernst-Moritz-Arndt-University in Greifswald, Germany, is part of a team that is implementing a telemammography project in the rural state of Mecklenburg-Vorpommern. He recently shared the obstacles that his deployment team encountered in building its system at the 2007 European Congress of Radiology (ECR) in Vienna.

The implementation of the nationwide screening mammography initiative in Germany began with pilot programs in 2001, and should see completion throughout the country by year end. In 2005, Fröhlich and his colleagues found themselves tasked with interconnecting CR mammography devices from three vendors: Agfa HealthCare of Mortsel, Belgium; Philips Medical Systems of Best, Netherlands; and Fujifilm Medical Systems of Tokyo. Workstations, telemammography services, and screening workflow control for the project was provided by Image Diagnost International of Munich, Germany.

Images from the CR mammography modalities needed to be sent to a facility for second reads on mammograms, which is part of the quality assurance provisos of the German screening mammography initiative. Adding to the complexity of the job, exams from the originating centers located throughout Mecklenburg-Vorpommern were being sent from various RIS/PACS and archive configurations.

Once the images reached the second-read facility, they needed to integrate with MammaSoft, a mammography information system developed by the Kassenärztlichen Vereinigung Bayern (KVB) that is used by participants in the screening mammography initiative. In addition, long-term archive capabilities had to be established for the images and their corresponding reports.

Fröhlich's group first tested a setup without an interface to MammaSoft using a multilink integrated services digital network (ISDN) for connectivity.

"Although the ISDN multilink worked reliably, it was obvious to us that in case of a real screening scenario we had to use faster connections," Fröhlich said. "In the actual network, we only use WAN/LAN and symmetric digital subscriber line (SDSL)-2048 connections as a basis for approximately 50 examinations a day, although we could handle more."

To ensure security and privacy, a certified virtual private network (VPN) handles all transmissions, and connected routers have been configured to accept only IP-specific addresses.

"Transfer formats are mainly HL7 and DICOM, although a deeper interoperability between the information system and the imaging and reviewing solution is achieved on a nonstandardized level," Fröhlich noted.

Connecting CR mammography devices from three different vendors to the system was a tricky and time-consuming job, particularly the implementation of DICOM modality worklist brokers, he said. The team decided to use the central PACS server at the secondary-read site as a temporary archive. Once the QA process had been completed, the studies were migrated to an external archive.

The first two weeks of deployment were tagged by the implementation team as a learning period for the radiologists and radiographers. User errors were expected and provided training and trouble shooting opportunities for the telemammography system administrators. Over the next two and a half months, Fröhlich said that no errors were reported with the system.

At the three-month mark, 120 cases showed errors due to undocumented changes and service shutdowns of the interface service between the imaging and reporting system and the telemammography system. However, not a single image was lost, Fröhlich said.

"In researching the cause of the errors, we discovered that the system had been handed off to support personnel who had not received the necessary training on how to administer the system," he said.

Training was arranged for the site administrators and the system has continued to function as designed, according to Fröhlich.

In the first six months since going live, the telemammography system has handled 4,176 patients, 12,528 data transfers, and archived slightly more than 1 TB of data. The latency rate between receiving the primary-read and secondary-read completion is within 12 hours, he said. The team is currently engaged in the process of developing tools for monitoring image and report workflow on both sides of the interface and extending the system throughout Mecklenburg-Vorpommern.

Although developing the system architecture and integrating its components was both a creative and technical challenge, the weakest link in the deployment turned out to be IT-support training.

"The teaching of responsible support personnel is very important so that undocumented changes on interfaces don't break down the whole system," he said.

By Jonathan S. Batchelor
AuntMinnie.com staff writer
April 16, 2007