Table 2. Differences in Regional Gray Matter Volumes between Patients with OCD and Controls.

Brain region (SVC)a	Direction of difference	Coordinates (x, y, z)b	BAc	Peak Z-scored	Number of voxelse	p (FWE)f
Overall OCD group (n=38) vs controls (n=36)
Left putamen	Decreased in OCD	−28, 12, 3	—	4.28	819	0.001
OCD subjects without major depression (n=25) vs controls
Left putamen	Decreased in OCD	−27, 14, 2	—	4.01	695	0.004
Left medial orbitofrontal cortex	Decreased in OCD	−13, 50, −9	10	3.32	59	0.025
Right medial orbitofrontal cortex	Decreased in OCD	14, 41, −2	10	3.64	49	0.011
Right anterior cingulate cortex	Decreased in OCD	14, 41, 2	32	4.08	418	0.004

^aEach region was circumscribed using the small volume correction (SVC) approach, with anatomically defined volume-of-interest masks.

^bTalairach and Tornoux (1988) coordinate of the voxel of maximal statistical significance within each region.

^cApproximate Brodmann's areas.

^dZ-score for the voxels of peak statistical significance within each volume of interest.

^eTotal number of contiguous voxels in each region that surpassed the initial cutoff of Z>3.09.

^fFamily-wise error (FWE) correction for multiple comparisons at the level of individual voxels within the respective volume of interest.