Classics in Neuroimaging: Imaging the Endocannabinoid Pathway with PET.

This Viewpoint aims to highlight positron emission tomography (PET) research studies that have shaped our understanding of the endocannabinoid system (ECS) through radiopharmaceutical targeting of cannabinoid receptors 1 and 2 (CB1 and CB2), and the enzyme fatty acid amide hydrolase (FAAH), in several brain health illnesses including addiction, schizophrenia, eating disorders, and post-traumatic stress disorder. Advances in radiochemistry, including 11C-carbonylation and radiofluorination of nonactivated aromatic rings, are accelerating the translation of radiotracers with optimal kinetics, bringing us closer to clinical PET research studies to image the enzyme monoacylglycerol lipase (MAGL) and enabling the imaging of unexplored targets in the ECS.