CT Scan

Computed axial tomography (CAT) is essentially a complex and more detailed form of the traditional X-ray. Tomography means ‘picture slices’ (from the Greek tomos mean- ing ‘slice’ and graphein meaning ‘to write’).

In the CT or CAT scanner, horizontal (or axial) ‘pictures slices’ are taken of the body. The CT scanning machine looks like a giant polo mint with a bed passing through the central hole. The large white ring structure houses the X-ray beam, with the detecting device on the opposite side. These both rotate around the patient on the bed, allowing full ‘slice’ images to be taken of the body.

The data recorded is quite complex and hence requires computational analysis to make the scan images that doctors use to diagnose diseases. In addition to producing a series of two-dimensional images, computer manipulation can add the images together to produce three-dimensional representations of the body and internal organs.