The Statistics Plugin provides volume histogramms for values in a ROI. The binning though is fixed to 10 (HU). So histograms of PET or MR values don't make much sense.
Furthermore for some new tools (e.g. PET SUV, Perfusion) it would be very usefull to be able to produce volume histograms. But since these novel parameters often have decimal values between 0 and 1, the current Histograms show only one peak.
Flexible binning, either dynamical binning width by a fixed number of bins or via user specification of number of bins/bin width would be very usefull