computed axial tomography (CAT) at English => English (The Britannica Concise) Of Explained:
Diagnostic-imaging method using a low-dose X-ray beam that crosses the body in a single plane at many different angles. Conceived by William Oldendorf and developed independently by Godfrey Hounsfield (b.1919) and A. M. Cormack, who shared a 1979 Nobel Prize for their inventions, this major advance in imaging technology became generally available in the early 1970s. Detectors record the strength of the exiting X rays; this information is then processed by computer to produce a detailed two-dimensional cross-sectional image of the body. A series of such images in parallel planes or around an axis can show the location of abnormalities (especially tumors and other masses) more precisely than can conventional X-ray images. See also brain scanning.