Questions about the Talairach to MNI function in the Rest Slice Viewer

Submitted by yaosir on

Dear experts,

When I used the Talairach to MNI function in the Rest, I found something strange. The original Talairach coordinates were (-34,12,-2.5) and (34,12,-2.5). When I used the the Talairach to MNI function in the Rest Slice Viewer, the corresponding MNI coordinates were   (-38,14,-9) and (36,14,-8). However, when I directly translated the Talairach coordinates to MNI coordinates in the ROI defination list, the corresponding MNI coordinates were   (-36,14,-8) and (38,14,-9). I suppose there may be something wrong.

In addition, I found that the original Talairach coordinates were symmetrical, but were asymmetrical after translation. Is that reasonable? I have also used another translation function (http://imaging.mrc-cbu.cam.ac.uk/imaging/MniTalairach), the results in this case were symmetrical as (34.3434,12.4845,-2.2585) and (-34.3434,12.4845,-2.2585).

Finally, I found that the only  integer coordinates could be used in the  the Rest Slice Viewer. I strongly suggest you to update it to support coordinates with decimal type.

Best,

Vincent

YAN Chao-Gan

Wed, 08/20/2014 - 17:08

Hi,

This is because RPI and LPI are complicated issues, especially in tal 2 mni or vice versa. The one in ROI-definition is more accurate.

Just round the coordinates in such a case. Decimal type doesn't add more information, especially if your voxel size is 3*3*3.

Best,

Chao-Gan