[Insight-users] BSplineDeformableTransform: Initializing from landmarks?

[Zachary Pincus]

Hello,

I am interested in the conditions under which the B-spline deformable 
transform is it more useful than the FEM-based deformable registration 
tools.

The main advantage appears to be the ability to add a "bulk transform" 
to the B-spline transform, so that you can simultaneously perform 
gross, rigid registration and more fine deformable registration, 
instead of requiring a two-step process. Is this correct? Are there 
other advantages? And what are the reasons one would prefer the other 
deformable registration methods?


Further, I am interested if there is any way to (directly or 
approximately) initialize a B-spline deformable transform with 
landmarks.

The only way that I can imagine is to generate a deformation field from 
the landmarks, use that field to deform the moving image, and then use 
the deformed image as the initial moving image for the B-spline 
transform. However, I'm not sure (a) how best to perform the initial 
deformation (1 iteration of a deformable registration filter that 
allows an initial field to be set?), (b) if too much image data would 
get mangled in the process, and (c) if at this point, the B-spline 
transform just isn't the right tool for the job.

Any thoughts or musings about either of these questions would be most 
appreciated.

Zach Pincus

Department of Biochemistry and Program in Biomedical Informatics
Stanford University School of Medicine