Would colon cancer show up in a abdominal ct scan ?

Ct not sensitive: Ct scan is a useful tool for pre operative evaluation and postoperative surveillance, however most colon cances would not be detectable by standard cat scan unless they were very large, or had obvious spread to the liver. A colonoscopy is the most sensitive screening test. Ct colonoscopy can be almost as sensitive as colonoscopy, but is a specialized test and requires the same prep as a colonoscop.

Maybe: If it is a large tumor, it will likely show up on a ct. Many colon cancers do not. The best test to check for colon cancer is without question a colonoscopy.

May, usually not: A regular ct scan of the abdomen, without bowel preparation is not an ideal way to detect colon cancer. Many lesions are likely to be masked by the fecal matter. Large lesions may be discernible. 3d ct scan, after bowel preparation would be better to detect colon cancer. Endoscopy is the better way, as polyp can be removed and suspicious lesions biopsied.

Sometimes: On regular ct. Seen better on ct colonography. See radiologyinfo.Org.