FIGURE 4.

Comparison of total V_T in various brain regions. V_T values were calculated in 7 subjects injected with ¹¹C-NOP-1A using unconstrained 2-tissue-compartment model for VOI data and Logan and MA1 methods for voxel data (Logan_voxel and MA1_voxel). (A) Mean V_T values obtained by both MA1_voxel (hatched bars) and Logan_voxel (white bars) were significantly lower than those obtained by 2-tissue-compartment model (black bars) (P < 0.05 by factorial repeated-measures ANOVA). Logan_voxel gave significantly smaller V_T values than MA1_voxel (P < 0.05). Data represent mean ± SD of all 7 subjects. (B) Scatterplot comparing mean V_T values from each region (excluding cerebellum) by MA1_voxel method vs. 2-tissue-compartment model in 40-y-old healthy man injected with 755 MBq of ¹¹C-NOP-1A. Simple linear regression was significant (Pearson R² = 0.95, P < 0.0001), with linear regression line equation y = 1.05x + 0.1. Solid line represents line of best fit. Dashed lines are 95% confidence intervals. FC = frontal cortex; PA = parietal cortex; OC = occipital cortex; TC = temporal cortex; MT = medial temporal cortex; CC = cingulate cortex; CA = caudate cortex; PU = putamen; TH = thalamus; CE = cerebellum.