Hy everyone,
I am trying to use slice timing correction in FEAT (FSL 5.0.1), using specific timing of slices. But I did not understand the reference I should use to create the slice timing file. The FSL wiki affirms that: "The units are in TRs, with 0 corresponding to no shift. Therefore a sensible range of values will be between -0.5 and 0.5." Does that mean that the slice that was acquired first at the beginning of my volume should be set to -0.5, and the last one be 0.5? Or should it be 0, and the last one should be 1. In other words, 0 refers to the start of the volume, or to the middle of the volume?
Actually, to be more specific, I have 40 slices acquired over a 4s TR, but all the slices are acquired in the first 2 (to generate a sound effect). In this way, if "0" means in the middle of the TR, my last slice (started at 1950ms and ended at 2000s), should be 0? Or should it be -0.00625 (in case we consider the middle time o that slice - 1975ms); or -0.0125 (in case we consider the beginning of the slice. In other word, should I consider the beginning of slice acquisition, or the middle time (between slice start and slice end) of the slice.
Thank you for your help
Best Regards
Paulo
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