In ViewTAC, and RoiStat4D dialog, when the curve is drawn the current Dynamic Index node is marked with the alternative color.

Implementing and initial variant for PET  4D motion compensation.  This is based on Dr. DeLeon comment during IDIF meeting.  Additionally a substantial rotation is observed (~2 degrees) betweeen MRI and some of the PET timepoints.
Standard 4D registration is used with some improvements to determine PET forground mask. Main challenge here is the speed of the registration due to the high PET timepoint count.