ABSTRACT
The discovery of X-rays in 1895 heralded a new era in the practice of medicine: visualization into the body without painful and often life-threatening surgery. X-ray imaging is essentially noninvasive. Modest risks are incurred due to the ionizing effect of the X-rays, but these risks are usually acceptable because of the diagnostic advantages provided by direct visualization of intracorporeal structures when such examination is indicated by illness and associated symptoms. X-ray computed tomography (CT) is primarily thought of as the precisely engineered machines that provide routine, noninvasive, clinical diagnostic transaxial images of the body. Three types of detectors are used in current X-ray CT scanners: scintillation; gas; and solid state. The scintillation detectors absorb the transmitted X-ray photons and produce light proportional to the amount of energy absorbed. The computerized display console of a modern X-ray CT system provides a wide variety of operator-interactive image manipulation and measurement capabilities.
