Leukocyte scintigraphy is a medical imaging test which displays the distribution of radiolabeled (for example labeled with 111In indium) leukocytes in the body to detect infection / inflammation. Whole-body scintigrams, and/or images of specific anatomic regions are recorded. Additionally, single photon emission computed tomography can be obtained.

See also Granulocyte Scintigraphy and Abscess Scintigraphy.

(LINAC) [Linear Particle Accelerator]
An electrical device that creates high-energy radioactive materials to treat cancers. It uses electricity to form a fast-moving linear stream of subatomic particles to collide with the target. LINACs for medical use produce a beam of 6-30 MeV energy.

The mole is the basic unit of matter. Definition: The amount of substance that contains as many elementary units as there are atoms in 0.012 kg of carbon-12.

Neutron radiation is one type of ionizing radiation. Neutrons get emitted from an atom by the fission process or by decay processes. In the upper atmosphere neutron radiation is produced by the interaction of cosmic radiation with air. Neutron radiation is used for the production of medical isotopes and certain direct medical therapies.

See also Neutron Activation, Neutron Activation Analysis and Neutron Capture.

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.