Unable to create a B-Spline Registration

Greetings, I am having some trouble creating a B-spline registration for 2 lung CTs, one with inhalation (0%) and one with exhalation (50%). The 50% image should be the fixed image. When doing a B-spline registration the following output image (I also put the 0%, 50% and settings):

Output Image:

0%:

50%:

Settings:

The output image looks basically the same as the 0% and I don’t believe anything is registered. Is there anything I am doing incorrectly?