Definition

A radioactive substance being studied in positron emission tomography (PET) imaging to find certain types of cancer. Fluorine F 18-fluoromethylcholine gets taken up by cells in the body and more of it is taken up by cancer cells than by normal cells. A PET scanner is used to find which cells in the body have taken up fluorine F 18-fluoromethylcholine. Also called 18F-choline, 18F-fluoromethylcholine, and 18F-FMCH.