It is valid to compare just the absolute volumes, but it might improve the results to divide by the ETIV. I would compute the average ETIV and divide by that. Alternatively, you can compute a relative change (vol2-vol1)/((vol1+vol2)/2)

On 2/15/20 10:23 AM, Halil Aziz VELİOĞLU wrote:

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Hi Mr/Mrs

We treated a group of patients. We performed volumetric analysis in freesurfer before and after treatment. Is it correct to take volumetric values directly into a paired test?

Or should we perform statistical analysis after dividing all values before and after treatment by "Estimated Total Intra Cranial Vol"? Is normalization by doing this way?

Best regards Halil Aziz -- Öğr. Gör. Dr. Halil Aziz Velioğlu Kognitif Sinirbilim Anabilim Dalı

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