use only side slices instead of relying on the brain mask to define the air mask
use only side slices instead of relying on the brain mask to define the air mask

oesteban/mriqc,poldracklab/mriqc,oesteban/mriqc,poldracklab/mriqc,oesteban/mriqc,oesteban/mriqc,poldracklab/mriqc,poldracklab/mriqc