Links & Glossary
Nuclear Med. Glossary A-D
The Nuclear Medicine Glossary by Richard Zimmerman, IBA Letters A to D
ability of a substance to bind to a receptor; it is a measurement of the strength of the binding.
As Low As Reasonably Achievable. Radiation protection policy related to the management of staff working in an ionizing radiation environment.
Alpha (α) (alpha radiation):
a particle emitted by a radioisotope and formed from a nucleus of helium containing two protons and two neutrons with potential therapeutic uses owing to strong ionizing power.
unit of radioactivity equal to one (1) disintegration per second. The Becquerel replaces the former curie unit, one curie being the equivalent of 37 billion Becquerel.
(β-) (beta-minus radiation): a particle emitted by a radioisotope and formed from a negatively charged electron, usable in therapy owing to its destructive potential.
(β+) (beta-plus radiation): a particle emitted by a radioisotope and formed from a positively charged electron (positron), an unstable anti-electron, which when it meets a negatively charged electron is annihilated to emit two gamma photons that move in exactly opposite directions and are therefore usable in imaging.
time period at the end of which a cell or tissue has eliminated half the quantity of a molecule present by a biological metabolic mechanism followed by excretion.
method of internal irradiation by the temporary or permanent introduction of radioactive implants. Examples: radioactive seeds marked with iodine-125 in prostate tumors, iridium wires in breast tumors, and phosphorus-32 patches.
non-radioactive precursor of a radiopharmaceutical containing all the elements that enable this medication to be reconstituted almost instantaneously, simply by adding a radionuclide solution.
Computerized tomography (CT):
cross-sectional imaging (usually with X-rays) allowing three-dimensional reconstruction.
physical contact leaving a deposit of radioactive material on a surface, matter, or person. The contaminated person is irradiated as long as the active matter has not been eliminated or the radioactivity has not fully decayed naturally.
abbreviation of computerized tomography.
unit of radioactivity; one curie equates to the radioactivity emitted by one gram of pure radium-226, one of the first natural radioactive materials available and isolated at the beginning of the last century. In principle, this unit should no longer be used because it was replaced by the becquerel (see entry for this word) in the 1980s.
see Internal radiotherapy.
reduction in the degree of radioactivity over the course of time.
the study and measurement of absorbed radiation.