Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Computed Tomography and Magnetic Resonance Imaging of the Digestive Tract

By

Jonathan Gotfried

, MD, Lewis Katz School of Medicine at Temple University

Reviewed/Revised Mar 2023
VIEW PROFESSIONAL VERSION

For CT and MRI of the digestive tract, doctors may give people substances that can be seen on the imaging test (contrast agents) to help distinguish one tissue or structure from its surroundings. Contrast agents may be given by mouth, by vein, by enema, or in combination.

CT Enterography and MR Enterography

Regular CT does not show the lining of the intestines well. A variation of the test, called CT enterography, allows doctors to clearly see the lining of the small intestine and look for tumors or narrowing of the intestines resulting from inflammation (strictures). For this test, people drink a large volume (about 1.6 quarts [1.5 liters]) of a liquid contrast agent such as barium. The contrast agent distends the small intestine so that doctors can see it better.

Magnetic resonance (MR) enterography is similar to CT enterography in that people drink a contrast agent before pictures are taken of their small intestine. It helps doctors see inflammation and other problems. This test is typically reserved for younger people, especially those with inflammatory bowel disease, so they are not exposed to radiation.

CT Colonography

This test generates two-dimensional and three-dimensional images of the colon that may show tumors or other problems.

Before the test, people are given laxatives or enemas similar to those required for a regular colonoscopy to thoroughly remove stool.

Immediately before the test, people drink a contrast agent, and their colon is inflated with gas from a tube inserted in the rectum so that doctors can see details better.

NOTE: This is the Consumer Version. DOCTORS: VIEW PROFESSIONAL VERSION
VIEW PROFESSIONAL VERSION
quiz link

Test your knowledge

Take a Quiz!
iOS ANDROID
iOS ANDROID
iOS ANDROID
TOP