A CT contrast agent is a substance used during a computed tomography (CT) scan to enhance the visibility of internal structures in the body. These agents help to highlight blood vessels, organs, and tissues, making it easier for doctors to diagnose conditions. They can be administered orally or through an injection, depending on the area being examined. The most common types of CT contrast agents are iodine-based, which absorb X-rays more effectively than surrounding tissues. This property allows for clearer images, aiding in the detection of tumors, infections, and other abnormalities. Safety measures are in place to minimize any potential allergic reactions or side effects.