An unstable form of a chemical element that radioactively decays, resulting in the emission of nuclear radiation. Also called a radioisotope.
- Radionuclide scan
A nuclear medicine examination in which a minute amount of radioactive material is labelled to commonly found substances in the body such as iodine or phosphate. As those radioactive substances go to their normal positions in the body, images of bones, thyroid tissue, and other organs are created. Also called an isotope scan.
- Radionuclide stress test
A procedure that involves injecting a radioactive isotope, typically thallium or cardiolyte, into the patient’s vein after which an image of the patient’s heart becomes visible with a special camera. The radioactive isotopes are absorbed by the normal heart muscle. Nuclear images are obtained in the resting condition, and again immediately following exercise. The two […]
Opaque to one or another form of radiation, such as X-rays. Radiopaque objects block radiation rather than allow it to pass through. Metal, for instance, is radiopaque, so metal objects that a patient may have swallowed are visible on X-rays. Radiopaque dyes are used in radiology to enhance X-ray pictures of internal anatomic structures. The […]
Sensitive to X-rays and other forms of radiant energy. For example, if a tumor is radiosensitive, it is potentially treatable with radiation therapy. The opposite of radiosensitive is radioinsensitive.
The treatment of disease with ionizing radiation. Also called radiation therapy. In radiotherapy, high-energy rays are often used to damage cancer cells and stop them from growing and dividing. A specialist in the radiation treatment of cancer is called a radiation oncologist. Like surgery, radiation therapy is a local treatment; it affects cancer cells only […]