is a type of x-ray
in which a picture of the body is recorded
on paper rather than on film
. In this technique, a plate of selenium, which rests on a thin layer of aluminium oxide, is charged uniformly by passing it in front of a ' scorotron
'. As X-ray photon impinges on this amorphous coat of selenium, charges diffuse out, in proportion to energy content of the X-ray. This occurs as a result of photoconduction
The resulting imprint, in the form of charge distribution on the plate, attracts toner particles, which is then transferred to reusable paper plates. In contrast to conventional X-rays, photographic developers
are not needed. Hence the term xeroradiography; 'xero' meaning dry in Greek.
It requires more radiation exposure.
Its use is in mammography.