open-discussion > Voxel dimension mismatch between FSL&MRICRON
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Oct 16, 2017  09:10 PM | Joselisa Paiva - Hospital Israelita Albert Einstein
Voxel dimension mismatch between FSL&MRICRON
Dear users,
We've drawn some lesion masks using both FSLVIEW and MRICRON. However, ww have noticed a strange mismatch in their output volume for the same masks and subjects. We have noticed that MRICRON changes the voxel dimension as if to make it isotropic. Is there a way that we can prevent it/turn it off? The strange thing is that the multiplication of the "new voxel dimension X number of voxels" is different, please see the "fslstats -V" output below.   
We really like MRICRON drawing feature and we would like to continue using it!
Any help is really appreciated! 
Thank you,

FSLINFO OUTPUT from mask drawn on MRICRON:
data_type FLOAT32
dim1 190
dim2 263
dim3 269
dim4 1
datatype 16
pixdim1 0.999940
pixdim2 0.999940
pixdim3 0.999940

fslstats test_MRICRON -V
19416 19412.478516

FSLINFO OUTPUT from mask drawn on FSLVIEW:
data_type UINT8
dim1 512
dim2 512
dim3 160
dim4 1
datatype 2
pixdim1 0.500000
pixdim2 0.500000
pixdim3 0.999940

fslstats test_FSLVIEW.nii.gz -V
76594 19147.341797 
Oct 17, 2017  12:10 PM | Chris Rorden
RE: Voxel dimension mismatch between FSL&MRICRON
Choose Help/Preferences and change your maximum dimensions from the default of 384 to a value larger than 512 (the maximum dimension in your image). At the moment, the software is downsampling your data. I would also uncheck the "Reorient images when loading" and "Rotate to nearest orthogonal" as FSL tends to assume your data is oriented precisely the same.
Attachment: warning.png