Got a bunch of MRIs from 1999 in the mail today. I was going to scan a bunch of them in, but after my first attempt I decided that I'll stop with this one as the scanner has a lot of trouble with the film.

MRIs work by knocking around hydrogen and measuring their spin. In effect, then, what you see with an MRI is water content, which is good for imaging the body, as we're so full of water. The whiter something is, the more water imbued it is.

This image shows my lumbar spine. The spinal column is the long white thing on the right and the horizontal pancakes are the discs. There's two things you can kinda notice in this. First, right before the spinal column hooks off to the right, there's three bumps in it where the discs are intruding. You'll also notice that those three discs are darker that the ones above them; hence, they have less water. The three discs were "fixed" in 1999, but the bottom of the three is the one that's been giving me trouble again.