Administration in medical imaging refers to the administration of contrast agent (dye) or radioactive material (radiopharmaceutical) into the body by injection, oral administration or by other route.

Beta radiation consists of high energetic electrons or positrons emitted spontaneously from nuclei in decay of some radionuclides. Also called beta particle and sometimes shortened to beta (e.g., beta-emitting radionuclides). Beta radiation is used for example in cancer treatment.
The average reach of beta radiation in tissue is 3.5 mm.

See also Beta Decay.

A depletion test is a rarely accomplished study, used to detect deficiency in iodine organification.

Disintegration is a synonym for radioactive decay.

A nonionic dimer consists of 2 joined nonionic monomers. Nonionic dimers are used as x-ray and CT contrast media.
Nonionic dimers have the lowest osmolarity. These contrast materials contain 6 iodine atoms for every 1 particle in solution (CM ratio=6). Modern CT techniques require fast bolus injections and thus low-viscosity, high-concentration, well-tolerated contrast agents. Nonionic dimers have the highest viscosity, which limits the clinical usefulness. Examples of nonionic dimers are iotrolan (Isovist®) and iodixanol (Visipaque).

See also Contrast Agents.