CAT scan

CAT scan [ c omputerized a xial t omography], X-ray technique that allows relatively safe, painless, and rapid diagnosis in previously inaccessible areas of the body; also called CT scan. An X-ray tube, rotating around a specific area of the body, delivers an appropriate amount of X radiation for the tissue being studied and takes pictures of that part of the internal anatomy from different angles. More recent scanners have a stationary X-ray tube and use deflecting coils and special reflectors to position the X-ray beam. A computer program is then used to form a composite, readable image. CAT scanning has revolutionized medicine, especially neurology, by facilitating the diagnosis of brain and spinal cord disorders, cancer , and other conditions. Ultrafast CT, or electron beam CT, is able to take pictures in a tenth of a second. It is useful in creating images of moving parts, such as the heart, without blurring.

CAT scan • n. an X-ray image made using computerized axial tomography. DERIVATIVES: CAT scan·ner n.

CAT scan (computerized axial tomography) X-ray technique for displaying images of cross-sections through the human body. X-ray sources and detectors slowly move around the patient's body on opposite sides, producing a changing ‘view’ of an organ. The data from the detectors is processed through a computer to display only the details relating to a specific ‘slice’ through the body.