I am using SPM12 (toolbox- CAT12) on MATLAB2017a 

1. CAT12 segmentation results are not same as gave before with same file xyz.nii
CSF GM WM
  Absolut volume 351 580 396
       Relative volume 26.4 43.7 29.9%  
                  TIV 1327
Second time
      CSF   GM WM
       Absolut volume 307 574 399
       Relative volume 24.0 44.8 31.2
TIV 1280


2. How could adjust grey matter, white matter threshold either on SPM12 or using CAT12