I am trying to do a small volume correction on a group analysis using an anatomical mask. I created a mask for left IFG using MRIcro following instructions on http://imaging.mrc-cbu.cam.ac.uk/imaging/SmallVolumeCorrection. I checked the mask against the uncorrected activation peaks in MRIcroN to make sure that the activation I was interested in fell within my anatomical mask. When I selected the mask as the image for the svc, the only area of activation that came up was a random dot in the right hemisphere. How is that possible if I'm restricting the region to the left IFG? I double-checked to make sure the mask was definitely in left hemisphere and the activation that I am interested in is in left hemisphere. When I do a small volume correction using a 10mm sphere around the uncorrected peak, I get that peak as significant at FWE p<.05, but I'd prefer to use the anatomical mask.
Any help would be greatly appreciated!