Extracolonic findings at CT colonography

CT colonography (CTC), also referred to as virtual colonoscopy, is a noninvasive CT examination of the colon. Usually performed without IV contrast, it allows detection of both intraluminal and extraluminal (extracolonic) disease. Several studies demonstrate that although extracolonic disease at CTC is found in the majority of patients, the detection of previously undiagnosed highly important findings (HIF) is much lower. The number of HIF can vary depending on the definition of an HIF, the patient population, as well as technical factors. This article will discuss the incidence and implication of detecting extracolonic findings at CTC.