Please help me To do metric test using fiesta and SPGR T! images

I have converted Fiesta and SPGR images using DWIconvert into .nrrd files and it is stored as DWI file. I applied Transforms and it has stored as new transform and new displacement file. Once I open to do metric test in General registration I could see only displacement file which is stored in convert section of Transform module. I cannot see any of nrrd original file in the list of moving and fixed image. How to do metric test for these images.

A post was merged into an existing topic: To do metric test for imported .nrrd images