I set up mri_gtmpvc to reduce the field of view to a bounding box around the head to reduce memory and computational loads. You can turn this off with --no-reduce-fovHi Dr Greve,
I followed the steps in WIKI to do SUV-surface based analyses + PVC. I have the following questions and I highly appreciate your input:
1. Why the dimension of the images (mgx.gm, mgx.ctx.gm and mgx.ctx.subgm) is not like the original SUV image that has been fed to the pipeline. i.e. I start with image-dimensions 128X128X128 : 2X2X2 and end up with 79X113X102 : 2X2X2
Also FOV is different as well between the original SUV image /256/ and the output mgx images /158/. How this happen? I am I doing something wrong?
Yes. MG works by estimating the contribution of non-GM to GM and subtracting it out. If the estimate is too high, then it can cause negative values.
2. Some voxels in the mgx images has negative signal intensity. is this normal?
Thank you for any clarification.
John
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