¥Note: A ROI
is defined by the values stored in voxels of the ÔmaskÕ dataset
HContiguity of voxels has no meaning to the ROI software
described below
HTwo voxels are in the same ROI if they have the same
value in the mask dataset (i.e., it doesnÕt
matter where they are located in the volume)
H
¥3dmaskave
HProgram to compute the average of voxels from a
functional dataset, with voxels
selected from a mask dataset (interactive version: ROI Average plugin)
HExample:
í 3dmaskave -mask ROI_fred+tlrc -mrange 1 3 \
í Ôfunc_fred+tlrc[2,4]Õ
H
H Will
print out (in the shell) one line of data for each of the 3 selected sub-bricks
from the input dataset func_fred+tlrc:
H
H 52.3674 [43450 voxels]
Âsub-brick #2 values averaged across all 3 ROIs 40.186 [43450 voxels] Âsub-brick #4 values averaged
across all 3 ROIs
å
åThe output above represents the average of all the voxels
collapsed across ROIÕs 1, 2, & 3, (specified by -mrange
1 3) in our mask dataset ROI_fred+tlrc
for sub-bricks #2 and #4 from dataset func_fred+tlrc