The PVC (VOI based) method provides three variants which are based on the same GTM methodology. The difference is, how the VOIs are obtained.
Methods 2,3 and 4 can only be applied for human brain images, whereas method 1 is generic. Note that the user may also derive himself contour VOIs from standard VOI templates, adjust them to the subject anatomy, and apply method 1. This allows him to take advantage of the rat and mouse templates for which an automated work-flow is not yet available.
The details of the methods are explained in the corresponding sections below.