[Bellvitge] Output hotspot perfusion values

[agarcia-ruiz]

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like
Output cbv, ph, psr hotspot (max value) in these ways:

Single 2x2x2 area (apply mean filter) with maximum
Ditto with 3x3x3
Top 8 voxels (not consecutive area) within ROI after gaussian smooth
Top 27 voxels after gaussian smooth

Output the (mean) value in each hotspot and the mean curve.
We would have rcbv_222_mean, rcbv_333_mean, rcbv_8_gauss, rcbv_27_gauss; psr_222_mean, ... 12 output values + 12 curves.

This not urgent, for a future Bellvitge release.