Nuclear medicine and radioactive substances

radioisotope

Radioactive form of an element; also called a radionuclide

radionuclide

Radioactive form of an element that releases energy as radiation

radiopharmaceutical

Radioactive drug containing a radionuclide combined with a chemical, administered for diagnostic or therapeutic purposes

radiolabeled compound

Compound tagged with a radionuclide for use in nuclear medicine

radiotracer

Radioactive substance used to follow a chemical's movement through the body

tagging

Attaching a radionuclide to a chemical and following its path in the body

tracer study

Study using radionuclides attached to chemicals and followed as they travel through the body

uptake

Rate at which a radionuclide is absorbed into an organ or tissue

half-life

Time required for a radioactive substance to lose half its radioactivity through disintegration

radioimmunoassay

Test combining radioactive chemicals and antibodies to detect very small quantities of substances in blood

in vitro

Process, test, or procedure performed, measured, or observed outside a living organism, often in a test tube

in vivo

Process, test, or procedure performed, measured, or observed within a living organism

thyroid scan

Nuclear medicine scan used to evaluate the thyroid gland; a radioactive substance is taken up by the thyroid

radioactive iodine uptake (RAIU) test

Nuclear medicine test used to evaluate thyroid function

bone scan

Imaging examination using a radiopharmaceutical taken up by bone tissue

perfusion lung scan

Scan using an injected radiopharmaceutical to trace blood flow through the lungs

ventilation lung scan

Scan using an inhaled radiopharmaceutical to trace its movement through the respiratory tract

ventilation-perfusion (V/Q) scan

Combined ventilation and perfusion scans used to evaluate for pulmonary embolism

lymphoscintigraphy

Nuclear medicine imaging of the lymphatic system

technetium-99m (Tc-99m)

Common medical radioisotope used in multiple organ scans

thallium-201 (Tl-201)

Radioisotope used to scan heart muscle

iodine-123 (I-123)

Radioactive iodine isotope used in thyroid scans

iodine-131 (I-131)

Radioactive iodine isotope used in thyroid cancer diagnosis and treatment

fluorodeoxyglucose (18F-FDG)

Radiopharmaceutical used in PET scanning

gadolinium (Gd)

Contrast agent commonly used for MRI

radiopharmaceutical uptake

Absorption of a radioactive substance into a particular organ or tissue