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fScan Reference Manual, Chapter 2 (CmdLineOptions): timebase

Timebase -- Uneven TR; TR align/create T1 map/use T1 map to adjust

usage: -timebase trs t1map wrtflg t0 u0

With no argument this will cause timepoints for each voxel to be shifted in time as though the data had been recorded at the same time as the first slice. This is done for each voxel (in each slice except the first) by interpolating NZ-1 additional data points (where NZ is the number of slices) between each pair of sampled time points using a quadratic spline function. All time points except the first are then simply replaced by the splined value corresponding to the acquisition time of the first slice.

When specified with arguments, this option allows you to specify uneven TR intervals to set the acquisition times, create a T1 map, and/or use a T1 map to adjust for variable T1 effects. Its args are:

  • trs - file name, or pdigm rec type or rec num for acquisition times. Times in secs (or 20 us ticks converted and offset automatically). If number of values < NT*NZ, times are beginning of each volume. Note: If TRS is a number with a decimal point (e.g. '1000.') it will be taken as the time (in secs) between slice 0 in successive volumes. In that case the TRs are constant, but the slices are unevenly spaced.
  • t1map - file name (or pdigm rec) of t1map(s) images (1/slice).
  • wrtflg - create new t1map based on trs and exp curves fit for each voxel
  • t0 - time zero offset (secs) for the first acquired image (default=0)
  • u0 - number of entries in TRS to ignore before first acquired image

See Also:
fScan Home,
fScan Manual,
Manual Help

jvs/fscan/manual/chapter2/timebase.txt · Last modified: 2014/08/04 16:03 (external edit)