imfuse and imref in 3d.

Dear Matlab Community:

I am trying to align two 3d-images (A and B) of different spatial resolutions where the transformation matrix from a coregistration is available. To test the coregistration I am transforming image A and trying to overlay it on B. The transformation is performed using

   -> tform   =  affine3d(T);
   -> [C, RC] = imwarp(A, RA, tform)

Where RA and RC are reference objects for images A and C, respectively, and RA was obtained with imref3d. The transformation is completed succesfully. However I lack a function like imfuse to use the "ZWorldLimits" to align images C and B for depiction. Furthermore, RC doesn't have the correct pixel spacing after scaling the image.

One could set it manually if imref3d had the option to have the "PixelExtentInWorld" being set after the transformation has taken place. It can be set when one creates the imref object for the first time, though, like RObj = imref3d(myImage, pixExtentX, pixExtentY, pixExtentZ ) I wonder why would that be?

Thanks for any hints, Jaime