<prompt> 18-FDG stands for:18-FI uorodeoxy glucose18-Fluorodioxy glucose18-Fluorodeoxy galactose18-Fluorodioxy galactose  <response>: Ans: A 18-FIuorodeoxy... POSITRON EMISSION TOMOGRAPHY PET L B 25th 136-37 PET is an extension of nuclear medicine, in which a positron-emitting substance such as 18F is tagged and used to assess tissue metabolic characteristics. Nuclear medicine also differs from other means of imaging, which are largely anatomically based, as it also provides functional information. The most commonly used radiolabelled tracer is 18F-2- fluara-2-deoxy-D-ghicose FDG, although other tracers can also be used in order to assess metabolic functions such as oxygen and glucose consumption and blood flow. 