Computed Tomographic (CT) Scanning

Computed tomography, originally called computed axial tomography (CAT or CT scan), takes its name from the Greek words 'tomos' (a slice) and 'graphe' (to write) - literally, a picture built from slices. The technique uses digital geometry processing to reconstruct a three-dimensional image of the inside of the body from a large series of two-dimensional X-ray images captured as the X-ray source rotates around a single axis around the patient. Because it collects a whole volume of X-ray absorption data rather than one flat image, a CT scan can be digitally manipulated after the scan - a process called windowing - to bring out different structures based on how strongly they block the X-ray beam, letting a radiologist highlight bone, soft tissue or air-filled spaces from the same underlying dataset. This is CT's main advantage over a conventional single X-ray: instead of one flattened two-dimensional projection, it produces a full three-dimensional reconstruction that can be viewed as a …