When someone I knew got some MRIs in 2015, I asked for the data to try to make a 3D visualization of it with a Vive:

Later, I also needed to get one because my family has a medical history of weird brain stuff. I got the data from that, too, and iterated on this prototype making the shader a little nicer. I made the quads fade in and out based on the direction you looked at them from:

I also added better opacity controls:

Then I put it inside my avatar, which means I can use VR to step outside my body and legitimately look inside my head at my own brain.

Using the Zed Mini on an Oculus Rift, I can do some creepy stuff with occlusion in XR