Radiopaque

Impenetrable by x-rays or any other form of radiation. Radiopaque dye (one that is highlighted on x-rays) is used in cerebral angiograms to detect the degree of narrowing or obstruction of an artery or blood vessel in the brain, head, or neck; in the diagnosis of...

Radiotherapy

The medical specialty concerned with the use of electromagnetic or particulate radiation in the treatment of disease. The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may...