Computer-aided detection, now commonly used for nodule detection, is becoming more integrated with PACS, a trend that streamlines workflow. The idea of integrating the two systems is gaining more widespread use as facilities try to maximize the potential that coordinating the processes can achieve, giving radiologists the ability to refer to CAD images during interpretation.

The lack of integration between PACS and CAD has been the biggest barrier to the use of CAD technology, according to Dr. Heber M. MacMahon, director of thoracic imaging at the University of Chicago Medical Center, a hub of CAD development.

"[CAD technologies] have not been tightly integrated into PACs, so it takes a lot of time to evaluate," MacMahon said. "If it takes more than a few minutes to bring up the interface and extract results, people won't use it in their practice because of the pressure to read large amounts of scans."

CAD and PACS developers have worked together to improve the software so that nodule detection can be done more quickly and reliably, he said.

Japanese researchers at Kyushu University hospital have integrated a server used for moving temporal-subtraction and nodule-detection images into PACS, allowing current and prior CAD images to be automatically loaded on display terminals, according to a report outlining their four-year experiment (J Digit Imaging 2008;21[1]:91-98).

The image-loading technique can easily be applied to other CAD systems, such as those for mammography, gastrointestinal exams, and CT, said Dr. Shuji Sakai, an associate professor of radiology at the university's school of medicine.

The report, however, did mention several problems associated with the integration process, including excessive false positives, difficulties with image orientation, and low image quality when temporal subtraction was performed on images obtained on different devices.

CAD software can be included in a stand-alone CAD workstation or be integrated in the PACS as PACS-based CAD.

In a report given at EuroPACS 2006, H.K. Huang, D.Sc., a professor of radiology and biomedical engineering at the University of Southern California, discussed a CAD-PACS software toolkit, developed at the school's Image Processing and Informatics Laboratory, that uses DICOM, HL7, and Integrating the Healthcare Enterprise profiles for integrating CAD results with PACS workflow.