I have asked the ANTs team regarding this matter but they suggested I ask the SCT team instead. I previously registered a 14 slice mFFE scan to the template using SCT and am currently calculating the determinant of the outputted deformation field from sct_register_to_template. I calculated the Jacobian by only considering the coordinates reflective of the templated image as the remaining values in the deformation field are very large and negatively impacted determinant calculation. Nevertheless, the calculated Jacobian files still have several planar, light striations. The respective deformation field does not possess such characteristics. I have attached a sample of the Jacobian determination, deformation field, and target file here. Any help for why this is happening is appreciated.