title: History, evolution, and current status of radiologic imaging tests for colorectal cancer screening.
abstract: Colorectal cancer screening is thought to be an effective tool with which to reduce the mortality from colorectal cancer through early detection and removal of colonic adenomas and early colon cancers. In this article, we review the history, evolution, and current status of imaging tests of the colon-including single-contrast barium enema, double-contrast barium enema, computed tomographic (CT) colonography, and magnetic resonance (MR) colonography-for colorectal cancer screening. Despite its documented value in the detection of colonic polyps, the double-contrast barium enema has largely disappeared as a screening test because it is widely perceived as a labor-intensive, time-consuming, and technically demanding procedure. In the past decade, the barium enema has been supplanted by CT colonography as the major imaging test in colorectal cancer screening in the United States, with MR colonography emerging as another viable option in Europe. Although MR colonography does not require ionizing radiation, the radiation dose for CT colonography has decreased substantially, and regular screening with this technique has a high benefit-to-risk ratio. In recent years, CT colonography has been validated as an effective tool for use in colorectal cancer screening that is increasingly being disseminated.
authors.affiliation: From the Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce St, Philadelphia, PA 19104 (M.S.L.); and Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco Veterans Affairs Medical Center, San Francisco, Calif (J.Y.).
authors.forename: Marc S
authors.initials: MS
authors.lastname: Levine
authors.forename: Judy
authors.initials: J
authors.lastname: Yee
mesh_terms: D001466:Barium Sulfate; D003111:Colonic Polyps / Q000000981:diagnostic imaging* / Q000266:history; D023881:Colonography, Computed Tomographic / Q000266:history / Q000295:instrumentation / Q000639:trends; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000266:history; D003287:Contrast Media; D055088:Early Detection of Cancer / Q000266:history / Q000295:instrumentation / Q000639:trends; D004733:Enema / Q000266:history; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D001466:Barium Sulfate