Hi,
I want to coregister 2 3D brain images (PET to CT) with rigid-body registration but without any rotation? i.e. translation only.
Can any of the realignment functions in SPM do this? (in any SPM version).
I have considered a 6 parameter registration and ignoring the 3 rotation parameters, or a centre of mass registration, but I haven't convinced myself these actually provide the best fit (with either east squares or mutual information).
I can think of examples where rotation-only is worse than [translation+rotation]-[translation] (at least in a least-squares sense) but I can't convince myself one way or the other about translation-only (or using mutual information instead).
Thought welcome please!
Cheers
Joel
PS I know MI/CC is more appropriate than Least Squares but if that's all that would work I'd take it!
|