Reducing the Rate of Repeat Imaging: Import of Outside Images to PACS

Repeat imaging at the transfer of care between institutions is a potential source of overutilization. The purpose of this study was to assess whether importing images obtained at one institution to the PACS at another institution reduces the number of repeat imaging examinations performed, sparing patients unnecessary cost and radiation. Informed consent was waived for this retrospective study, which included 267 patients who had undergone CT or MRI of the abdomen at our or another institution within 4 months before transarterial chemoembolization. Patients were divided into the following four groups based on the availability of their images from institutions other than ours (outside images): outside imaging performed but images not available; outside images available on CD or film but not imported; outside images imported to PACS; and no outside imaging, that is, all imaging performed at our institution. The rates of repeat imaging in the four groups were compared. When outside images were not available, 72% (13/18) of patients underwent repeat imaging; when outside images were available but not imported, 52% (14/27); when outside images were imported to PACS, 11% (9/79); and when imaging was performed only at our institution, 13% (18/143). Patients whose outside images were imported were significantly less likely to undergo repeat imaging than were both groups whose outside images were not imported (p < 0.001), and their rate of repeat imaging was similar to that of patients who did not undergo outside imaging (p = 0.79). After adjustment for potential confounders, including age, sex, referring institution, and size and number of lesions, the odds that a patient whose images were imported would undergo repeat imaging were significantly lower than those of a patient whose outside images were not imported (odds ratios, 31 for images not available and 9.0 for images available but not imported; both p < 0.001) and were similar to those of a patient who underwent all imaging at our institution (odds ratio, 0.71; p = 0.51). Importing outside images to PACS reduces the rate of repeat imaging.