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 reim-bursement 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 pa-tients (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 popula-tion has a low prevalence of high-risk lesions, and the additional cost of their evaluation is relatively small.
