Importing images from one institution to the PACS at another reduces the number of repeat imaging exams when transferring care of a patient between two facilities, according to a study published in the March issue of the American Journal of Roentgenology.

In the effort to reduce unnecessary utilization of diagnostic imaging, transfer of care between institutions is a definite challenge. If imaging done at one institution is not readily available at another, repeat imaging is often the consequence. Even when images are physically transferred with the patient, repeat exams can result.

“Review of these images, which are most commonly on a CD, is critical to clinical decision making,” wrote Michael T. Lu, MD, and colleagues at the University of California, San Francisco (UCSF). “However, viewing the images on CD can be cumbersome and time-consuming; furthermore, as a physical medium, a CD may not be available when and where it is needed.”

To investigate whether importing images from one institution to the PACS at another reduced repeat imaging, Lu and colleagues performed a retrospective study of patients who had undergone CT or MRI of the abdomen within four months before transarterial chemoembolization. Patients were divided into groups based on whether or not the patient was imaged at a second institution prior to UCSF and whether those priors were available only on physical media or imported into the PACS at UCSF.

Of the 267 patients included in the study, 143 received imaging only at UCSF, but among the patients who had outside imaging, repeat imaging rates were significantly lower when those images were imported to the PACS. Only 11 percent of patients whose images were imported into the PACS underwent repeat imaging, compared with 52 percent of patients who had outside images on CD or film that weren’t imported. When no outside images were available, 72 percent of patients underwent repeat imaging.

“Patients who brought their outside images to our institution and had the images imported were nearly five times less likely than patients whose outside images were not imported to undergo repeat imaging,” wrote the authors. “Furthermore, patients whose outside images were imported and patients who underwent all imaging at our institution had similar rates of repeat imaging.”

The authors noted that physicians at their institution have been quick to recognize the benefits of importing outside images as more than half of images were imported, and the number of outside imaging studies imported daily to the PACS doubled between 2006 and 2009. Lu et al suggested that other institutions should import outside images into PACS.

They recognized, however, that there are a number of reasons why institutions may not import outside images, including legal exposure issues and financial concerns.

“Importing outside images requires resources—at our institution, workstations, storage, and personnel. These costs are not reimbursed. Even at institutions that have had success with reimbursement for formal review of outside images, the amount is far less than the opportunity cost to the institution of repeating the imaging.”

The authors said vendors should adhere to DICOM and Integrating the Healthcare Enterprise standards to ensure generated media are importable. Internet-based image sharing networks also will play a role.

“We suspect that once fully implemented, use of internet-based image sharing will reduce the rate of repeat imaging,” wrote the authors. “Nonetheless, we expect that just as film persists many years after the proliferation of CDs, use of CDs will continue. We suggest that institutions planning on implementing internet-based image sharing also make provisions for importing images from CD to PACS.”