optical coherence tomography (OP-tih-kul koh-HEER-ents toh-MAH-gruh-fee)
A procedure that uses infrared light waves to give three-dimensional (3-D) pictures of structures inside tissues and organs. The pictures are made by a computer linked to the light source. Also called OCT.
Source: The National Cancer Institute's Dictionary of Cancer Terms
(http://www.cancer.gov/dictionary)