APA Dictionary of Psychology

a radiographic technique for quickly producing detailed, three-dimensional images of the brain or other soft tissues. An X-ray beam is passed through the tissue from many different locations, and the different patterns of radiation absorption are analyzed and synthesized by a computer. Because a CT scan produces many slice-by-slice pictures of the head, chest, or abdomen, it is possible to locate abnormalities, such as lesions or tumors, without exploratory surgery. Also called computer-assisted tomography; computerized axial tomography (CAT); computerized tomography. See also magnetic resonance imaging.