FSL flirt manual code example

Example 1: fsl flirt

#!/bin/sh

# Use FSL flirt to register label masks 
# with nearest neighbor interpolation. 
# because the label values should never be interpolated.
# This example assumes: 
# an existing 0.5mm standard brain (MNI152_T1_0.5mm_brain)
# an existing flirt matrix from 1 mm to 0.5 mm (stand1stand0.5.mat)

 flirt -in atlas -datatype int -ref MNI152_T1_0.5mm_brain \
 -interp nearestneighbour \
 -init stand1stand0.5.mat -applyxfm -out atlas_0.5mm

Example 2: fsl flirt

#!/bin/sh

# Some viewers (like MRIcron) do not handle anisotropic voxels well. 
# FSL can easily convert an image with anisotropic voxels into one 
# with isotropic voxels in the same space using -applyisoxfm

# reslice current image into 1mm isotropic
flirt -in anat_CT_axial -ref anat_CT_axial -applyisoxfm 1 -out anat_CT_axial_1mm

# reslice current image into 0.5 mm isotropic voxels.
flirt -in anat_CT_axial -ref anat_CT_axial -applyisoxfm 0.5 -out anat_CT_axial_0.5mm