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Dear Bruce Fischl,

Hi, I'm Yoonho.
In the previous post, "Re:[Freesurfer] Inquiry about process time by use "recon-all" (Fri, 12 Jan 2018 12:29:19-0800)", I found that the process time for recon-all depend on both how abnormal the anatomy is and how high the CNR of your scan is.
  1. Does "how abnormal the anatomy" mean that there is an anatomical abnormality due to a disease based on MR image and "how high the CNR of your scan is" mean that there is a CNR, [x_mean (gray matter) - y_mean (white matter)] / standard deviation_air (background)?
  2. Related to process time for recon-all based on the FS ver.7.2.0, is open-mp effect stronger than acquisition parameter optimization effect? Which one is more helpful in reducing the process time?

In the longitudinal analysis for freesurfer, 
  1. Is it possible to use longitudinal analysis of MR images obtained from equipment with different magnetic field strengths (1.5T vs 3T) in time series for the same subjects?
Looking forward to your feedback.
Thank you very much.    

Sincerely,
Yoonho