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Dear Freesurfer experts, I got the area of a cluster by two methods, and found the results were inconstant.
Method 1: During group level analysis, the individual surface was normalized to fsaverage. I exported the cluster area and label file by command mri_surfcluster. The command ws as followed:
mri_surfcluster --in ./sig.nii.gz --subject fsaverage --hemi lh --centroid --annot aparc --thmin ${thp} --sign ${sigsignTemp} --no-adjust --minarea ${tharea} --sum area${tharea}.${sigsignTemp}${thp_infilename}.cluster.summary --o area${tharea}.${sigsignTemp}${thp_infilename}.cluster.nii.gz --ocn area${tharea}.${sigsignTemp}${thp_infilename}.ocn.nii.gz --olab $Dir_Subj_fMRI/$out_dir_group/$analysis/$contrast/label_area${tharea}.${sigsignTemp}${thp_infilename}/label
Method 2: I calculated the cluster area using the label file outputed by mri_surfcluster via the matlab funciton read_curv. I did this to test the method for calculating the area of a label manually drawn by me. 1, I first got the area of each vertex by the command area = read_curv('../fsaverage/surf/lh.area'); 2, I red the IDs of vertices in the label file and added 1 3, I got area values of vertices in the label file and summed them.
I found the areas calculated by the Method2 were much smaller(except one ROI) than the ones exported by mri_surfcluster as shown below.
Area from Method 1： # ClusterNo Size(mm^2) NVtxs Annot 1 833.94 1999 postcentral 2 578.52 1300 precuneus 3 243.78 463 middletemporal 4 184.72 344 inferiorparietal 5 111.76 292 insula
Area from Method 2： ClusterNumber Area(mm^2) NVtxs AnotomicalRegion 1637.39 1999 postcentral 2 480.44 1300 precuneus 3 140.37463 middletemporal 4 166.33344 inferiorparietal 5112.76292 insula
What's the reason? Where did I do wrong in the method 2?
Thanks.
Best,
zhiwei
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Zhiwei Wang（王志伟), Associate Investigator
International Center for Primate Brain Research
Center for Excellence in Brain and Intelligence Technology
Institute of Neuroscience,Chinese Academy of Sciences
Room 215, Building #5, 500 Qiangye Road, Shanghai, 201602,China