What is CT?

CT stands for Computed Tomography; a technique used to view the soft tissue and bone in the body.

CT uses X-Rays to obtain images from different areas of the body, these images are transmitted to a computer to process the information and produce cross sections of the body. This gives doctors and radiologists more information about various conditions and helps give a clear diagnosis.

Computerised Tomography or CT scanning is an extremely useful diagnostic imaging tool, which enables us to obtain sectional images or 'slices' through the body. The CT scanner uses an X-Ray tube, but instead of recording the image onto film, a series of detectors are used to measure the attenuation of the X-Ray beam as it passes through the body. Many hundreds of readings are taken from various angles as the X-Ray tube and detectors revolve around the patient's body. This information is then passed to a very powerful computer, which produces a cross-sectional image. In conventional CT, the patient table is then advanced by a predetermined increment and another slice obtained. This continues until the part of the body being examined has been covered.

The advent of Spiral CT technology enabled the table to advance continually as the tube and detectors revolved, thus producing a continuous spiral (or volume) of data which the computer could then process into sectional images. This has greatly improved the speed at which CT data can be acquired so that the entire chest, for example, can be examined in a single breath hold.