X-ray computed tomography

X-ray computed tomography (CT) is a minimally invasive medical imaging technique that uses 2D X-rays to create 3D images of the internal structures of the body. X-rays are absorbed by different body parts in varying degrees; in an image, soft tissue body parts that allow X-rays to pass through show up grey, and hard body parts like bone that block X-rays show up white.

In CT, a series of X-rays are taken by numerous rotating X-ray beams, so that the body is imaged from all angles. Many image 'slices' are taken, which are then built up into 3D images using digital geometry processing. Because of the inherent high-contrast resolution of CT, tissues that differ in density by just 1 per cent can be distinguished in the resulting images.