CAT Scan Without Contrast: What to Expect & Alternatives

Computed axial tomography, also known as a CAT scan, is a highly-developed diagnostic procedure which requires use of a contrast material in most patients. Other arrangements may be made for patients who cannot take the contrast material.

Why Contrast Material Is Used

• Contrast material is used to enhance the body's ability to display on this diagnostic imaging test.

Types of Contrast

• There are three types of contrast material used: an iodine-based dye which is injected intravenously, a chalky liquid which is ingested, and one given through the rectum as an enema, according to Medline Plus, the online library of the U.S. National Institute of Health.

Who Must Have the Contrast

• Most patients must have at least one of the contrasts administered, but sometimes the injection and the drinkable liquid will both be used.

Who Is Exempt

• Johns Hopkins Medicine will make other arrangements for patients who have multiple myeloma or are diabetics with kidney failure. Other precautions are taken with patients who are allergic to iodine.

When a CAT Scan Is Necessary

• A CAT scan is a highly-sophisticated procedure which can be used to detect cancers, small breaks in bones and the size of tumors and infectious masses, among other things, says radiologyinfo.org.