Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «R»:
Radiologic: Having to do with radiology. ...
Radiologist: A physician specialized in radiology, the branch of medicine that uses ionizing and nonionizing radiation for the diagnosis and treatment of disease.
Like other physicians, a radiologist must have graduated from an accredited medical school or school of osteopathy, passed a licensing...
Radiology: The branch of medicine that uses ionizing and nonionizing radiation for the diagnosis and treatment of disease.
Historically, radiology involved the use of ionizing radiation including X rays for the diagnosis of disease and X rays and gamma rays for the treatment of disease.
Radiology, interventional: The use of image guidance
methods to gain access to the deepest interior of most organs and
organ systems. Through a galaxy of techniques, interventional
radiologists can treat certain conditions through the skin
(percutaneously) that might otherwise require surgery....
Radiolucent: Anything that permits the penetration and
passage of X-rays or other forms of radiation. Radiolucent is as
opposed to radiopaque (which refers to anything that blocks
the penetration of X-rays).
Plastic is usually radiolucent. If a child swallows a radiolucent
plastic paperclip, that...
Radiomimetic: Imitating radiation.
A radiomimetic drug is one that imitates the effects of radiation as in the case of chemicals such as nitrogen mustards which are used in cancer chemotherapy.
The "mimetic" part of "radiomimetic" comes from the Greek verb "mimeisthai" meaning "to imitate" and from...
Radionuclide: An unstable form of a chemical element that radioactively decays, resulting in the emission of nuclear radiation. Also called a radioisotope....
Radionuclide scan: An examination that produces pictures
of internal parts of the body. The patient is given an injection or swallows a small amount of radioactive material (a radionuclide). A scanner machine then measures the radioactivity in certain organs. Also called an isotope scan....
Radionuclide stress test
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. Nucle...
Radiopaque: Anything that does not let X-rays or other
types of radiation penetrate. Radiopaque objects
block radiation. They are opaque to radiation.
A metal object, for example, is typically radiopaque. If a child
swallows a coin and it goes down into the stomach, it is easily
visible in the ...
Radiosensitive: Sensitive to X-rays and other forms
of radiant energy. For example, a tumor may be radiosensitive, and
therefore potentially treatable with radiation therapy. The opposite
Radiotherapy: 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.
Radiotherapy, stereotactic: Radiation therapy in which a
number of precisely aimed beams of ionizing radiation coming from
different directions meet at a specific point, delivering the
radiation treatment to that spot....
The celebrated radioactive element discovered by Marie and Pierre Curie in 1898....
Radius: In anatomy, the radius is the smaller of the two bones on the thumb side of the forearm. (The bigger one is the ulna).
The word "radius" comes unchanged from the Latin meaning a spoke in a wheel which this bone was thought to resemble. The word "radiation" is derived from the same Latin wo...