Warpcorrect problem

Hi experts,

I used ants to register subject DWI space to MNI space. And I composed all ants output warp and affine images by:

warpconvert dwit12mni.mif displacement2deformation t12mni_deform.mif
transformcompose dwi2t1_affine.mif t12mni_affine.mift12mni_deform.mif dwi2mni_warp.mif

This dwi2mni_warp.mif warps dwi space image to MNI space correctly except for edges, by

mrtransform dwibrain.mif -warp dwi2mni_warp.mif mnibrain.mif

I checked the warp mif: t12mni_deform.mif looks good but dwi2mni_warp.mif has wired edge:

It may comes from composing affine operatation to warp images. I want to use warpcorrect to fix it, but dont know how to set -marker parameter. Any ideas?