Computes an average DWI image from input data. The average may be computed over all the data or over particular shells defined by a range of b-values.
For example, the average b=0 image can serve as a reference for motion correction. Alternatively, the mean or median DWI at some b-value can be useful for normalization to a structural image.
The user may select the b-values over which to average. This allows the selection of subsets of multi-shell data, or to select a single shell where the actual b-values vary from their nominal value.
A voxelwise average (mean or median) of the selected DWI data.
Get the average of all the measurements
averagedwi -inputfile dwi.nii.gz -schemefile A.scheme > mean_all.Bfloat
Get only DWI measurements on a shell at b=1000, given variation in diffusion weighting actually achieved by the scanner varies by +/- 20 s / mm^2:
averagedwi -inputfile dwi.nii.gz -schemefile A.scheme -minbval 990 -maxbval 1010 -outputfile mean_b1000.nii.gz