Binding to D 2 /D 3 Dopamine Receptors in Humans on the High-Resolution Research Tomograph PET Scanner

regions (caudate and putamen). Among D3-rich regions, variability was low in the pallidum (6%) but higher in substantia nigra (19%), thalamus (14%), and hypothalamus (21%). No significant mass carry-over effect was observed in D3-richregions,althoughatrendinBPNDwaspresent in the substantia nigra (−14% ± 15%). Because of the relatively fast kinetics, low-noiseBPND parametric images were obtained with both SRTM and SRTM2 without spatial smoothing. Conclusion: 11 C- (1)-PHNO can be used to compute low-noise parametric images in both D2- and D3-rich regions in humans.