Hi Stam,

i executed bedpostx_datacheck on the bedpostx directory and the following is the log on the console

===================================
/Space/jay/DTI_PWD_baseline_JA_bedpostX/d103/data
data_type      FLOAT64
dim1           180
dim2           180
dim3           75
dim4           31
datatype       64
pixdim1        1.3329999447
pixdim2        1.3329999447
pixdim3        2.0000000000
pixdim4        1.0000000000
cal_max        0.0000
cal_min        0.0000
file_type      NIFTI-1+

/Space/jay/DTI_PWD_baseline_JA_bedpostX/d103/nodif_brain_mask
data_type      INT16
dim1           180
dim2           180
dim3           75
dim4           1
datatype       4
pixdim1        1.3329999447
pixdim2        1.3329999447
pixdim3        2.0000000000
pixdim4        1.0000000000
cal_max        0.0000
cal_min        0.0000
file_type      NIFTI-1+

num lines in /Space/jay/DTI_PWD_baseline_JA_bedpostX/d103/bvals
     31
num words in /Space/jay/DTI_PWD_baseline_JA_bedpostX/d103/bvals
     31
num lines in /Space/jay/DTI_PWD_baseline_JA_bedpostX/d103/bvecs
     31
num words in /Space/jay/DTI_PWD_baseline_JA_bedpostX/d103/bvecs
     93

===================================

when i created bedpostx directory, i used whole brain binary mask
bedpostx <indir> [-n 2] [-w 1] [-b 1000]

but later when i run qboot, i used probability mask(Right_Accumbens) extracted from the standard H-O atlas
qboot -k data.nii.gz -m Right_Accumbens.nii.gz   -r bvecs -b bvals

BW
Jay