Objective: To determine the prevalence of extracolonic findings at computed tomographic colonography (CTC) and estimate the cost of the workup of newly discovered potentially significant lesions.
Subjects and methods: An electronic information system was used to review all patient data before and after the CTC in a mixed cohort of 376 patients. Extracolonic findings were categorized into the CT Colonography Reporting and Data System classification. The impact of additional diagnostic workup was estimated using Medicare reimbursement for relevant extra services.
Results: There were 51 patients (13.6%) with E3 and 16 (4.3%) with E4 findings. At least 1 extracolonic finding was found in 272 patients (72.3%). There were 520 extracolonic findings, of which, 447 (86.0%) were classified as low clinical significance, E2. Only 7 (12.5%) of 56 E3 lesions and 7 (41.2%) of 17 E4 lesions received additional diagnostic workup. The total additional cost of evaluating E3 and E4 lesions was $13.07 per CTC.
Conclusions: A mixed (screening and nonscreening) CTC population has a low prevalence of high-risk lesions, and the additional cost of their evaluation is relatively small.