CT scan is a noninvasive radigraphic technique called computed tomography. It is a test that applies computer technology and digital imaging techniques to X-ray studies to produce images of cross section of the body. It is a medical imaging method employing tomography where digital geometry processing is used to generate a three-dimensional image of the internals of an object from a large series of two-dimensional X-ray images taken around a single axis of rotation. CT produces a volume of data which can be manipulated, through a process known as windowing, in order to demonstrate various structures based on their ability to block the X-ray beam.