Receptor imaging by PET and SPECT: focus on the opiate receptor

Receptor imaging by PET and SPECT offers distinctive advantages over the more established flow/metabolism imaging methods, including improved chemical specificity and improved sensitivity in detecting changes in disease. Radioligands are available for PET and SPECT imaging of many neuroreceptors including the opiate receptor, the dopamine receptor and the muscarinic cholinergic receptor. A new focus of interest is the imaging and quantification of presynaptic neurotransmitter reuptake sites. Clinical applications of mu opiate receptor imaging are discussed for epilepsy, Alzheimer's disease and dementia.