Hello.

Thanks for your interest.
I think the problem is wit the fact that the hyperintense regions are mostly on the borders of WM and GM/CSF, and so in the extracted GM tissue map the WMH and non-WMH regions are `looking' the same. I would try changing the preproc parameters, reduce the bias correction parameter (all these are in _preproc.m file).
Do all your images end up getting zero detections? Or does this happen to few?