4.To view and begin drawing an ROI mask (or several ROIs)
on this blank anatomical overlay
dataset, go to the main AFNI interface and [Switch Overlay] to be the empty anatomical dataset you will be
editing. Also turn the overlay ON with [See OverLay]
5.Start drawing the ROI mask into this blank anatomical
overlay dataset. Voxels inside the ROI mask will receive a non-zero value
(you decide what value to give them). Values outside the ROI mask will remain
zero
åBe sure to save the results by pressing [Save], [SaveAs] or [DONE] in the ROI
plugin GUI ([Quit] will exit the ROI plugin without saving your work)
6.Convert the anatomical-resolution ROI dataset into a
dataset at the resolution of the
functional (statistical) datasets you want to analyze with the ROI
åNote: The ROI and
functional datasets may already be at the same resolution, if you are operating in +tlrc coordinates
åResolution
conversion of masks is done with program 3dfractionize
7.Use programs 3dmaskave, 3dmaskdump, and 3dROIstats to
extract ROI-based information about
functional datasets
åAlso can use the ROI Average plugin to extract interactively the average of a dataset over a ROI