
Computed tomography (CT) was invented over three decades ago and has since developed to become an important tool in clinical investigation and diagnosis. CT is a specialised x-ray procedure in which cross-sectional images of the body are produced, to give a detailed picture of body tissues and organs.

The procedure involves a patient lying flat on a table and being passed through a doughnut shaped CT scanner. CT is used to visualise internal organs to help diagnose different types of diseases including cancer. It is also used to identify anatomical abnormalities of tissues and to detail injury to organs after trauma. The procedure carries little risk and is painless.
There are estimated to be more than 30,000 CT scanners in use around the world, which demonstrates how useful a tool it is for medical diagnosis and investigation.
CT of the chest
CT of the head