I have had trouble getting close registration of images from child subjects to the MNI152 standard brain. Particularly, I am having issues with the caudate and lateral ventricles. It seems the ventricle in the standard brain is significantly larger than those in our child subjects leading to significant misregistration and poor segmentation during FIRST. I have tried to use -inweight with FLIRT to increase the weighting of this region and FNIRT without success. Any suggestions or advice would be greatly appreciated. Also, I am curious if there is capability to generate my own standard brain and associated FIRST models?