Definition of Tomography

Tomography: The process for generating a tomogram, a two-dimensional image of a slice or section through a three-dimensional object. Tomography achieves this remarkable result by simply moving an x-ray source in one direction as the x-ray film is moved in the opposite direction during the exposure to sharpen structures in the focal plane, while structures in other planes appear blurred. The tomogram is the picture; the tomograph is the apparatus; and tomography is the process.

See also: Computed tomography (CT); Computed tomography colography; Computerized axial tomography scan (CAT scan); Electron beam computerized tomography (EBCT); Positron emission tomography (PET scan).