Links & Glossary

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• Nuclear Med. Glossary A-D
• Nuclear Med. Glossary E-H
• Nuclear Med. Glossary I-O
• Nuclear Med. Glossary P-R
• Nuclear Med. Glossary S-Z

Nuclear Med. Glossary P-R

The Nuclear Medicine Glossary by Richard Zimmerman, IBA Letters P to R

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.

Positron:

see Beta-plus.

Posology:

dosage and procedures for administering a medicine.

Prevalence:

total number of patients at a given time for a defined disease. It is an estimation of how common a disease is in a population.

Proton:

a positively charged elementary particle, constituting the nucleus of the atom together with the neutron.

Proton therapy:

method of external radiotherapy using a proton beam.

Rad:

see Gray.

Radiation:

a beam of invisible particles or waves emitted by a source. Also, it corresponds to the process of transmission of energy in corpuscular (α, β^- particles, etc.) or electromagnetic form (visible light, ultraviolet, infrared, X, γ, etc.)

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. This period (half-life) is different for each radionuclide, but is a precise physical constant for a given radionuclide and is influenced by neither temperature or pressure.

Radioactivity:

property of certain radionuclides which emit particles spontaneously (electrons, protons, neutrons, nuclei) and/or α-, β-, γ-, or X-rays.

Radiochemical:

a radioactive substance not intended for human use.

Radiochemist:

a chemist specializing in the manufacture of radioactive substances; therefore, in the field of nuclear medicine, a specialist in the development of labeling, and in the field of nuclear physics, a specialist in the chemistry of radionuclides.

Radiochemistry:

chemistry of substances incorporating a radioactive element.

Radioelement:

an element where all the isotopes are radioactive, e.g., those of the plutonium or uranium groups (term often used wrongly in the place of radionuclide or radioisotope).

Radioisotope:

an unstable isotope that decays over the course of time, emitting radiation (see Radionuclide).

Radiologist:

specialist in X-ray imaging.

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. The word in the plural, ‘radioisotopes,’ is frequently used wrongly to designate all radionuclides.

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.

Radiotherapist:

physician specializing in treatment by external radiotherapy. If the radioactive substance has to be injected into a patient, this task is entrusted to the nuclear physician.

Radiotherapy:

method of therapy (treatment of a disease) based on the use of radiation, of whatever sort (X-, α-, or β-rays, neutrons, etc.).

Rem:

see Sievert.