CT scanning

CT scanning is particularly useful in the emergecy setting and in helping sort out difficult cases. It is not as good as MRI in the local staging of rectal cancer. It is quite useful in staging the liver.

Figure 6: This patient had a number of colonscopies over many months for suspected inflammatory bowel disease but the histology on the biopsies taken was inconclusive. This scan was performed and showed a large mass in the caecal area which could have been either inflammatory or neoplastic. Unfortunately, the operative and post resective findings proved it to be a locally advanced caecal tumor.

A new and potentially useful variation is CT virtual colonoscopy where the patient has a high resolution CT scan. An detailed image of the colon is then constructed from the images and the clinician may look at the inside of the colon using the software. The main disadvantage is lack of the ability to get tissue for diagnosis. The main advantage is patient comfort and avoidence of the risk of colonic perforation from colonoscopy.