Use SPM12 (no idea which version you used) and make sure the alignment is approximately correct before you begin (Check reg with the MNI images released with SPM12). Best regards, -John ________________________________ From: SPM (Statistical Parametric Mapping) <[log in to unmask]> on behalf of Abby tang <[log in to unmask]> Sent: 15 April 2019 08:41 To: [log in to unmask] Subject: [SPM] Skull removal error Hello. I have met something wrong when I use SPM> PET&VBM> segment. I attached the pictures blow. Can you help me and give me some advices in detail. Thank you!