antsRegistration for enlarged ventricles

Hi everyone,

I have perinatal stroke data with very enlarged ventricles and am having trouble using antsRegistrationSynQuick to get them into MNI space. It looks like ants is not shrinking the ventricle down to MNI size.

Ultimately, I would like to use the warps from registration to apply the transforms to the lesion mask. The goal resulting mask would cover most of the right hemisphere of the example given below.

I have tried different variations. This is what seems to be the closest so far: \
		-d 3 \
		-m ${MNI_template} \
		-f ${lesion_masked_T1w_brain} \
		-t b \
		-o ${template_name}_${transform_type}_to_${T1w_image_name}_ \
		-x ${inverse_lesion_mask} \
		-j 1 

The resulting Inverse Warped (Subject → MNI Space) - I would expect the right ventricle to be reduced in size, with the lesion taking up more room. The right hemisphere has also not been increased to be equal to the left.

This is my first post, so please let me know if I’ve left out any important information.

Thank you!