I performed following steps
- register T1 image to MNI space and compute the transformation matrix
- then take the inverse of that matrix
- apply registration using inverse matrix to AAL atlas and tranform it into my subject space (T1 space)
- now i am overlapping mask (tumor mask) with this atlas based image
tumor mask has three different labels. but in AAL atlas space intensity values has been changed so how i can get three different ROI based on tumor mask?