Left anterior oblique is an oblique (usually 45 degrees) position adjacent to the left side.

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.

Lifetime is the mean life of a particle or in case of a radioactive nucleus equal to its decay time.

See also Half-Life, Decay.

(LOR) Line of response is in PET imaging the path between two detectors used to localize the tracer. Based on the size of the detectors - volume of response (VOR) is used instead of LOR.

See also Annihilation Coincidence Detection.

(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.