**9.1 Tomography**

Tomography is a generic term formed by the Greek words "Tomo" (slice) and "Graph" (picture). So tomography refers to imaging by sections or sectioning, through the use of any kind of penetrating wave. A device used in tomography is called a tomography, while the image produced is a tomogram. Conventional film-based tomography, also called body section radiography is, a radiographic technique designed to image more clearly objects lying within a plane of interest. This is accomplished by blurring the images of structures lying outside the plane of interest through the process of motion "unsharpness."

In conventional medical X-ray tomography, sectional image is taken through a body by moving an X-ray source and the film in opposite directions during the exposure.
