Judy Yee, MD Naveen N. Kumar, MD Suchitra Godara, MBBS Janice A. Casamina, MD Robert Hom, MD Gregory Galdino, MD Peter Dell, MD Darice Liu, MD Published online 10.1148/radiol.2362040166 Radiology 2005; 236:519 –526 1 From the Department of Radiology, Veterans Affairs Medical Center (114), 4150 Clement St, San Francisco, CA 94121 (J.Y., N.N.K., S.G., G.G., D.L.); and the Department of Radiology, University of California School of Med- icine, San Francisco (J.Y., N.N.K., J.A.C., R.H., G.G., P.D.). Received January 28; revision requested April 6; revision re- ceived September 24; accepted De- cember 29. Address correspondence to J.Y. (e-mail: judy.yee@radiology.ucsf .edu). Authors stated no financial relation- ship to disclose. Author contributions: Guarantor of integrity of entire study, J.Y.; study concepts and design, all au- thors; literature research, all authors; clinical studies, J.Y.; data acquisition, J.Y., N.N.K.; data analysis/interpreta- tion, all authors; statistical analysis, all authors; manuscript preparation and editing, J.Y., N.N.K., R.H.; manuscript definition of intellectual content, J.Y., N.N.K.; manuscript revision/review and final version approval, all authors © RSNA, 2005 Extracolonic Abnormalities Discovered Incidentally at CT Colonography in a Male Population 1 PURPOSE: To evaluate prospectively the prevalence of incidental extracolonic findings at computed tomographic (CT) colonography and to estimate the cost of their imaging work-up in male patients with high and those with average risk of colorectal cancer. MATERIALS AND METHODS: This study was approved by the institutional review board, and informed consent was obtained from all patients. The study was com- pliant with requirements of the Health Insurance Portability and Accountability Act. CT colonography was performed in 500 men (mean age, 62.5 years). Of these patients, 194 (38.8%) were at average risk for colorectal cancer and presented for routine screening. The other 306 (61.2%) were at high risk for colorectal cancer. Extracolonic findings were recorded and categorized as either clinically important or clinically unimportant. Clinically important findings were defined as those that necessitated further diagnostic studies or medical or surgical follow-up. The cost of additional imaging required to further characterize important lesions was estimated. Chart review was performed (mean length of follow-up, 3.6 years) to determine whether any important findings were missed at CT colonography. The Fisher exact test was used to determine whether there was a difference between the percentages of average- and high-risk patients with extracolonic findings. RESULTS: Of the 500 patients in the study, 315 (63.0%) had extracolonic findings, and 45 (9.0%) had clinically important extracolonic findings. Of the 596 extraco- lonic findings identified, 50 (8.4%) were thought to be clinically important. The mean additional cost to work up important findings was $28.12 per CT colono- graphic examination. There were no significant differences between average-risk and high-risk patients in the percentages of extracolonic findings (P = .25) or clinically important extracolonic findings (P = .11). CONCLUSION: A substantial number of both average- and high-risk patients un- dergoing CT colonography will be found to have clinically important extracolonic findings. There was no increased morbidity or mortality associated with the addi- tional evaluation of extracolonic findings. The cost of evaluating these lesions is low, given the potential for positive effects on patient care. © RSNA, 2005 Computed tomographic (CT) colonography is a proposed method for examining the colon for polyps and cancer. To date, CT colonography has been found in multiple studies to be nearly as sensitive as fiberoptic colonoscopy in the detection of polyps 10 mm and larger (1–5). Unlike endoscopic methods for colorectal cancer screening, CT colonography has the added ability to depict extracolonic lesions in the abdomen and pelvis (6 – 8). Inciden- tal lesions are often detected with many diagnostic imaging examinations and present a challenge to physicians because of both the potential benefits and the risks of identifying such lesions. Detection of potentially serious asymptomatic lesions at an early and curable stage can prompt meaningful medical follow-up or surgical intervention, ultimately lead- ing to decreased morbidity and mortality. Many incidental lesions are benign, however, Gastrointestinal Imaging 519 R adiology