Hello Cheng,

From what I understand of DARTEL (Carlton, please correct me if I am wrong), is that the values in the modulated GM files can be interpreted as grey matter density.  If you average the values in each of the regions defined by the LPB40 atlases, then you result is the average grey matter density withen each ROI.  From what I see in your plot it appears as though the last ROI in your sequence has a very high GM density compared to the rest, my guess is that this is for a large ROI, and if you average rather than just sum, this effect will be less pronounced.

As far as the ReHo, Dr. Xinian Zuo has generously provided me with a script for performing ReHo analysis.  I will get to this later this week and hopefully post the ReHo maps early next week.

Cheers,
Cameron