Is a CT Scan With Contrast Harmful?

While the chance of a CT scan causing a problem is small, some individuals may experience an allergic reaction to the contrast dye, states WebMD. The material may also cause problems for diabetics or individuals taking metformin.

Some types of computed tomography, or CT, scans may increase the risk of cancer in those who undergo many radiation tests, according to WebMD. This increased risk is also higher in children and young adults. The test itself does not cause pain. The dye, known as contrast material, is injected into an arm vein, a joint or the rectum. In some cases, it is swallowed. The dye allows the organs and internal structures to be seen more clearly on the CT pictures.

A CT scan is used to examine many parts and organs of the body, explains WebMD. It takes pictures of the heart, lungs, liver, pancreas and intestines. It is used to study blood vessels, bones, the spinal cord, arms and legs, and the chest. A CT scan of the abdomen can detect tumors, bleeding in the belly, appendicitis, inflammatory bowel disease and enlarged lymph nodes. A CT intravenous pyelogram scan uses injected contrast material to detect urinary tract blockages, kidney stones, infections, growths and other urinary tract diseases.