Thanks for the (as usual) wonderful response, Alfonso.  I asked because this came up as a criticism by two separate reviewers of a paper we recently submitted.  Coincident with the data we collected we also obtained ASL, which did show a global increase in perfusion between baseline and follow-up in one of our groups, but this increase was only found for summed global perfusion.  There were no regional perfusion increases that survived uncontrolled p<0.001.  To address the criticism, I was planning on running suggested non-aCompCor work around and see if there is any appreciable differences in the global signal correction vs. aCompCor approach.  Any particular issues I need to watch out for when setting up this non-aCompCor processing pipeline?

Warm regards,
Jeff