Hi Cate,

That binarized map is essentially the thresholded, clustered map one might get from 3dClusterize, just without the clusters ordered by size. If you want to get the cluster table and volume, go ahead and run 3dClusterize. For example, assuming that dataset is called ETAC.global.2sid.5perc.nii.gz, consider:

3dClusterize -ithr 0 -idat 0 -inset ETAC.global.2sid.5perc.nii.gz \
                     -NN 2 -1sided RIGHT_TAIL 0.5 -clust_nvox 2 \
                     -pref_map ETAC.clust.order.nii.gz

That will threshold that binary dataset at 0.5, use NN2 neighbors, and require at least 2 voxels for a cluster (since they are already clustered, 1 voxel is probably enough, though some programs might whine about that).

Does that seem reasonable?

To verify cluster counts, compare the output table against:

3dhistog ETAC.global.2sid.5perc.nii.gz
3dhistog ETAC.clust.order.nii.gz

- rick