“How accurate is a CT scan for colon cancer?”

A CT scan is not the preferred method to “detect” colon cancer. Most colon cancers are confirmed using colonoscopy, endoscopic photography, and biopsy. CT scans are primarily used to search for metastatic disease including involvement of the liver, larger lymph nodes, the presence of intra-abdominal masses and ascites. CT scans are used to evaluate the lungs for distant metastatic disease. The CT scan offers an image and does not provide histologic proof of cancer (unless done in conjunction with a biopsy - usually percutaneous and with a needle.

Possibly this question is “how accurate is CT colonography” which is a method to evaluate the colon for polyps and masses using computerized tomography. The method does work to find problems in the colon, but does not prove a diagnosis. Most patients who have an abnormal CT colonography require colonoscopy for definitive diagnosis.

A CT scan can detect the presence of abnormalities but colon cancer can only be confirmed through a biopsy.

To detect colon cancer is by doing a colonoscopy. If a mass is found on colonoscopy, the doctor will do a biopsy. CT scan is used to see if there are other masses in the colon.

Only so endoscopy stool examination for blood are the initial test. CT is usually done for staging.