CT Enterogram

This is a special kind of CT scan. It is a scan which specifically examines the small bowel and is a sensitive test for identifying structural abnormalities, such as narrowing’s, strictures or inflammation within the small bowel. It is often used to assess the extent and severity of inflammation in patients with Crohn’s disease in who small bowel inflammation is suspected. In addition to allowing the radiologist to look at the small bowel it may also give some limited information about the other solid and hollow structures within the abdomen and pelvis.

 

It is important for patients having this test to be able to swallow as in order to obtain clear pictures it is necessary for patients to drink oral contrast solution which helps to define the structures within the bowel. Contrast shows up as a different shade or colour on the CT so enables the radiologist to identify differences between the wall and the content of the gut.  In addition intravenous contrast helps to delineate areas where blood flow is higher. This may be relevant in the setting of inflamed tissue, which often has greater blood flow and so shows up more when intravenous contrast is given. This helps radiologists to identify areas of inflammation within the gut and to differentiate them from areas of scarring, which often have relatively less blood flow.

 

One of the disadvantages of CT scanning is that it exposes patients to a sall dose of radiation, and if patients are having repeated scans this radiation exposure may accumulate and have a risk of slightly increasing cancer risk (perhaps 1 in several thousands, for each scan). Similarly the administration of intravenous contrast may have effects on kidney function, whilst these are usually minor and transient the administration of intra-venous contrast should be considered carefully, particularly in patients who are at risk of kidney disease. In patients who are taking metformin there is also a slightly increased risk of metabolic abnormalities when they are exposed to CT contrast.

 

CT Colonoscopy is a particular technique used to identify polyps in the colon in patients in whom colonoscopy may not be the preferred option.