Hi FSL Gurus, BETpremask give much better output than BET in our 3T t1 datasets. BET leaves on some images large amounts of non-brain tissue. question 1: Is brain volume on the BETpremask output changed? question 2: Can I change BET input parameters (ie -f and -g and -c) in the BETpremask script? Newbie that I am to FSL scripts, I don't see the BET command line in the BetPremask script, compared say to the BETALL script. question 3: One of our ultimate goals is to use SIENA. If BETpremask is the beest option for our data, is there a way to pass BETpremask output to SIENA? Substitute BETpremask for BET in script? TIA, Rob