What Is an "Entrance Dose" of X-Rays?By John W. Gofman, M.D., Ph.D. and Egan O'Connor,
Editor of CNR Books
February 2000
An "entrance dose" of x-rays is the dose absorbed at the surface of the skin where the x-ray beam enters. An x-ray beam enters the body from the direction of the x-ray tube. A small share of the beam exits from the body on the opposite side, where it exposes the film or other image-receiver. The share of the beam which never exits from the body is absorbed as extra energy by the body's internal organs and bones.