How to get the coordinates of centre of mass for each ROI

Dear all,

I downloaded the Harvard-Oxford atlas (ho_labels.csv and ho_roi_atlas.nii). These two files can be downloaded from http://preprocessed-connectomes-project.org/abide/Pipelines.html, where youu can find "The subcortical and cortical ROIs were combined and then fractionated into functional resolution using nearest-neighbor interpolation. [Atlas][Labels]". Through load_nii('ho_mask_pad.nii'), I can get the index of voxel in each ROI. Fox example, I use the following code to get the index of the ROI labeled 10

load_nii('ho_mask_pad.nii');

tmpt=ans.img;

idx = find(tmpt ==10);

[x,y,z] = ind2sub([65,77,63],idx);

X=mean(x)

Y=mean(y)

Z=mean(z)

The result is (X,Y,Z)=(29.7, 38.5, 27.6). But in the ho_labels.csv, ROI 10 is “Left Thalamus”. The position of (29.7, 38.5, 27.6) does not correspond to “Left Thalamus”.

Would you please give me some suggestions? Thank you.

Best

Erick