computed tomography scan
also called a CT scan or CAT scan. An imaging test in which many x-rays are taken from different angles of a part of the body. These images are combined by a computer to make cross-sectional pictures that show details of internal organs much better than standard x-rays. Except for when the dye is injected (needed in some but not all cases), this is a painless test that can be done in an outpatient clinic. See also outpatient, imaging tests, ionizing radiation.