[Insight-users] MultiResMIResgistration - scaling

[Christos Panagiotou]

hi all
some questions concerning multiResMiRegistration

i am trying to use the MultiResMIRegistration application
to register PET and MRI volumes. I would like to ask if the rigid 
transformation
incorporates scaling in the registration procedure or it implements 
translation and rotation but not scaling

i tried to register a PET volume (128x128x31) against an MRI volume 
(256x256x55). The application allies them
however it does not scale the bigger volume to to "fit" the smaller one. 
It somehow "crops" the MRI (larger) volume
to fit the 128x128x31 of the PET. Is there any option to incorporate 
this? i ve seen definitions of rigid registration that incorporate 
scaling and some that they dont...

also, if volumes are of different dimensions, should the moving volume 
always represent the smaller volume (from the two)?

finaly, do you know if the BSplineDeformableTransform incorporates 
scaling (as it is non-rigid i assume it must do)

thank you all
any help will be appreciated
christos