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Glossary for Nuclear medicine
Affinity:
Ability of a substance to bind to a receptor.
ALARA:
As Low As Reasonably Achievable. Radiation protection basic role.
Alpha (α) (alpha radiation):
A particle emitted by a radioisotope and formed from a nucleus of helium containing two protons and two neutrons.
Becquerel(Bq):
Unit of radioactivity equal to one (1) disintegration per second.
Beta-minus
(β-) (beta-minus radiation): a particle emitted by a radioisotope and formed from a negatively charged electron.
Beta-plus
(β+) (beta-plus radiation): a particle emitted by a radioisotope and formed from a positively charged electron (positron).
Biological half-life:
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.
Cold kit:
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.
Contamination:
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.
CT:
Abbreviation of computerized tomography.
Curie (Ci):
Unit of radioactivity; one curie equates to the radioactivity emitted by one gram of pure radium-226, it was replaced by the becquerel .
Decay:
Reduction in the degree of radioactivity over the course of time.
Dosimetry:
The study and measurement of absorbed radiation.
Effective dose:
The equivalent dose corrected by the weighting coefficient relating to the irradiated tissue (0.05 for the thyroid, 1 for the whole body) expressed in sieverts.
Effective half-life:
Radioactive half-life corrected by the biological half-life. With this information, the practitioner can estimate how long a radioactive substance that has been ingested by or injected into a patient will take before generating an effect on the organism (or a certain type of cell or tissue).
Equivalent dose or Dose equivalent:
Absorbed dose corrected by a weighting coefficient relating to the radiation (1 for X-rays, β-rays, and γ-rays, 20 for α-rays), expressed in sieverts.
FDG (Fluorodeoxyglucose):
Substance labeled with fluorine-18, most frequently used for diagnosis based on positron emission tomography technology.
Galenic:
Study of the method of administering a medication.
Gamma(γ):
Radiation of a shorter wavelength than X-rays emitted by certain radionuclides and with very high energy; usable for diagnostic imaging.
Generator:
Tool for the production of a radioisotope by the decay of a parent radionuclide from which it is regularly separated by a physical means.
Gray (gy):
Unit of absorbed dose corresponding to one joule per kilogram.
Incidence:
Number of new cases of a disease appearing during a certain period of time
Intracavity radiation:
the emission of rays from a source placed inside a cavity: uterus, throat.
Intraoperative radiation:
Irradiation during a surgical operation.
Ionizing:
(Radiation): electromagnetic or corpuscular radiation capable of producing ions (positively or negatively charged atoms or molecules) directly or indirectly during its passage through matter.
Irradiation:
Exposure to radiation, without physical contact with the radioactive material.
Isotope:
All the atoms, the nucleid of which have the same number of protons,
Label:
An entity (simple or complex) which, due to its radiation or its color, can be monitored in a complex biological system.
Labeling:
Method of chemical fixation of a radioisotope on a non-radioactive molecule.
MRI:
Magnetic resonance imaging; another name for medical nuclear magnetic resonance.
Nuclide:
Atomic nucleus.
PET:
Positron emission tomography. Imaging modality based on the detection of the two gamma photons generated by a positron emitter.
PET/CT:
Imaging technology combining positron emission tomography and X-ray analysis.
Posology:
Dosage and procedures for administering a medicine.
Radiation:
A beam of invisible particles or waves emitted by a source.
Radioactive half-life (or period):
time at the end of which half the atoms initially present in a radioactive element have disappeared through spontaneous transformation..
Radioactivity:
Property of certain radionuclides which emit particles spontaneously (electrons, protons, neutrons, nuclei) and/or α-, β-, γ-, or X-rays.
Radioisotope:
An unstable isotope that decays over the course of time, emitting radiation (see Radionuclide).
Radionuclide:
Radioactive atomic nucleus. Two radionuclides compared with each other are called radioisotopes if they belong to the same family of atoms (e.g. the radioisotopes of iodine, such as iodine-123, -124, or -131) and radionuclides in other cases.
Radiopharmaceutical:
Radioactive medication intended for diagnosis or therapy in the field of nuclear medicine.
Radiopharmacist:
A hospital pharmacist specializing in the labeling and handling of radiopharmaceutical preparations intended for administration to a patient.
Radiopharmacy:
A laboratory, principally located in a hospital, equipped to handle radioactive substances for injection into patients.
Radiophysician:
Physician specializing in the handling and production of radionuclides.
Scanner :
An imaging tool using X- or γ-rays that provide virtual sectioning (scans) of the area being analyzed.
Scintigraphy :
Method of imaging based on recording γ or β+ radiation emitted by a substance injected into the patient which concentrates in a particular organ or tissue .
Sealed source :
A radioactive substance placed in a sealed container, irradiating but not contaminating.
Sievert(Sv) :
Unit of equivalent dose, corresponding to a corrected dose of the ionizing effect of the radiation (for X, β+, and γ radiation, 1 Sv = 1 Gy). Previously the Rem was used, with one Sievert equivalent to 100 Rems.
Specific activity :
Radioactive activity value comparing the activity of the radionuclide with the total mass of the element present..
Specific concentration :
Value that determines the degree of radioactive substance per volume unit. (expressed in Becquerels per volume unit).
Specific/specificity :
Describes molecules that only target a single type of cell or receptor.
SPECT :
Single-photon emission computed tomography. The imaging modality based on the measurement of γ-ray emission.
Tomography :
radiography providing a clear image of a single cross-section.
X-rays :
Invisible short wave light radiation produced either directly by a radioactive substance or indirectly by excitation of atoms, and capable of traversing material
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