4DCT

Four-dimensional computed tomography (4DCT) is a type of CT scanning which records multiple images over time. It allows playback of the scan as a video, so that physiological processes can be observed and internal movement can be tracked. The name is derived from the addition of time (as the fourth dimension) to traditional 3D computed tomography. Alternatively, the phase of a particular process, such as respiration, may be considered the fourth dimension.

Fluoroscopy is a similar technique to 4DCT, however it refers to the introduction of a time element to 2D planar radiography, rather than to 3D CT.