X-ray
Definition
noun
- a ray with a very short wavelength, which is invisible, but can go through soft tissue and register as a photograph on a film. X-rays are used in diagnosis in radiography, and in treating disease by radiotherapy.Example The X-ray examination showed the presence of a tumour in the colon.
- a photograph taken using X-raysExamples The dentist took some X-rays of the patient’s teeth. • He pinned the X-rays to the light screen.
- an examination in which X-ray photographs are takenExample All the staff had to have chest X-rays.
verb
- to take an X-ray photograph of a patientExample There are six patients waiting to be X-rayed.
COMMENT Because X-rays go through soft tissue, it is sometimes necessary to make internal organs opaque so that they will show up on the film. In the case of stomach X-rays, people take a barium meal before being photographed (contrast radiography); in other cases, such as kidney X-rays, radioactive substances are injected into the bloodstream or into the organ itself. X-rays are used not only in radiography for diagnosis but as a treatment in radiotherapy as rapidly dividing cells such as cancer cells are most affected. Excessive exposure to X-rays, either as a person being treated, or as a radiographer, can cause radiation sickness.