radiologist, interventional A radiologic subspecialist who uses fluoroscopy, computerized axial tomography (CT), and ultrasound to guide wires and catheters for performing procedures such as biopsies, draining fluids, inserting catheters, and dilating or stenting narrowed ducts or vessels. See also radiology, interventional.
radiologist A physician who specializes in radiology, the branch of medicine that uses radiation for the diagnosis and treatment of disease. A radiologist can subspecialize and become, for example, a radiation oncologist or an interventional radiologist. See also radiation oncologist; radiologist, interventional.
radiologic Having to do with radiology.
radioisotope A version of a chemical element that has an unstable nucleus and emits radiation during its decay to a stable form. Radioisotopes have important uses in medical diagnosis, treatment, and research.
radioinsensitive Not sensitive to X-rays and other forms of radiant energy. For example, if a tumor is radioinsensitive, it cannot be successfully attacked by using radiation therapy. The opposite of radioinsensitive is radiosensitive.
radioimmunoassay A very sensitive, specific laboratory test (assay) that uses radiolabeled and unlabeled substances in an immunological (antibody-antigen) reaction.
radiography The process of obtaining film records (radiographs) of internal structures of the body. Radiography is made possible by X-rays passing through the body to act on a specially sensitized film.
radiograph In medicine, an X-ray or a film produced through X-ray.
radioallergosorbent test See RAST.
radioactive tracer A radioactive molecule that can be sent through the body’s circulatory or urinary system, with its progress followed by a radiation-sensitive machine.
radioactive iodine A version (isotope) of the chemical element iodine that is radioactive. Abbreviated RAI. RAI is used in diagnostic tests as well as in radiotherapy of the thyroid. It may be used in the treatment of hyperthyroidism and cancers of the thyroid. It directly radiates thyroid tissues, thereby destroying them. RAI should not be…
radioactive Emitting energy waves due to decaying atomic nuclei. Radioactive substances are used in medicine as tracers for diagnosis and in treatment to kill cancerous cells.