Picture archiving and communication system: effect on reporting of incidental findings

To determine the effect of a picture archiving and communication system (PACS) on reporting of incidental findings outside the area of interest, with a focus on lumbar spinal magnetic resonance (MR) imaging.

Results of 2,500 lumbar spinal 1.5-T MR examinations were reviewed. These included 500 consecutive lumbar spinal MR reports for each of 5 years: 1 year prior to PACS introduction, 1 year during transition to PACS, and 3 consecutive years thereafter. Incidental findings cited in the reports were tabulated, and the frequency, organ system involved, and radiologist recommendations in each case were noted and compared, as were projected expenses based on the Medicare payment scale for recommended follow-up studies. Results of available follow-up studies were also reviewed.

The number of incidental findings increased from 19 before PACS to 31 during transition and 53, 49, and 50 after PACS implementation, which resulted in a maximum increase of 179%. The increase was statistically significant during each post-PACS year. The most common incidental findings involved potential renal, pelvic, hepatic, pulmonary, and lymph node abnormalities. The total number of recommended follow-up studies increased from five before PACS to 15 during transition and 32, 22, and 18 after PACS implementation, with a maximum increase of as much as 540%. Recommended ultrasonographic studies increased the most from two in the pre-PACS year to 11 during transition and 27, 17, and 14 in the 3 post-PACS years. Follow-up expense increased by a mean of 146% after PACS implementation from 4,221 dollars per 1,000 studies in the pre-PACS year to 9,307 dollars, 13,426 dollars, 10,558 dollars, and 8,252 dollars thereafter. Of the 202 incidental findings, four represented occult malignancy, which is an expense of 5,721 dollars per diagnosis.

The introduction of PACS into radiology practice for lumbar spinal MR imaging appears to be associated with an increased number of reported incidental findings and recommended follow-up studies.