Radiocontrast agent

Radiocontrast agents are a type of medical contrast medium used to improve the visibility of internal bodily structures in X-ray-based imaging techniques such as computed tomography (CT), radiography, and fluoroscopy. Radiocontrast agents are typically iodine or barium compounds. When an agent improves visibility of an area, it is called "contrast enhancing".

Magnetic resonance imaging (MRI) functions through different principles and thus utilizes different contrast agents. These compounds work by altering the magnetic properties of nearby hydrogen nuclei.

Types and uses

Radiocontrast agents used in X-ray examinations can be grouped based on its use.

Iodinated (intravascular)

Iodine-based contrast media are usually classified as ionic or non-ionic. Both types are used most commonly in radiology due to their relatively harmless interaction with the body and its solubility. Contrast media are primarily used to visualize vessels and changes in tissues on radiography and CT. Contrast media can also be used for tests of the urinary tract, uterus and fallopian tubes. It may cause the patient to feel as if he or she has urinated on him- or herself. It also puts a metallic taste in the mouth of the patient.