Computed tomography colonography

Colorectal cancer is a leading cause of cancer morbidity and mortality in the United States. CT colonography, frequently referred to as "virtual colonoscopy," plays an increasingly important role in the screening and characterization of colorectal cancer, as well as the surveillance of suspicious polyps and post-treatment monitoring. This article describes the epidemiology, pathobiology, diagnosis, and treatment of colorectal cancer, and the roles of CT colonography and other imaging modalities in screening, surveillance, staging, and post-treatment monitoring. CT colonography techniques, including patient preparation, fecal tagging, colon insufflation (inflation), and the emerging technology of computer-aided detection also are covered.