Cat scan (Computerized Axial Tomography), sometimes also referred as CT scan, is a technique of obtaining X-ray pictures of thin slices of the body without even putting a scalpel to it. The technique comes to help in locating or identifying tumours or blocked blood vessels in such soft tissues as the brain or in large organs such as the liver which cannot be photographed by the usual X-ray techniques.
CAT scanning is a modification of the usual X-ray technique. In CAT, the part of the body to be scanned is placed inside a ring. The ring has an X-ray gun at one side and a detector on the opposite side. The X-ray beam from the gun is received by the detector after passing through the body.
While scanning, the whole ring is slowly turned round the body exposing every bit of it in that plane to X-ray. The intensity of X-ray coming out of the body at any point depends on the density of organs lying along the path of the X-ray beam. Thus the detector records varying amount of X-rays coming out of the body. A computer connected to the detector processes all the inputs into a flat picture, of few microns thick cross-section.
