If you're likely to benefit from one (e.g., you had cancer), your doctor should be able to make that happen. Otherwise, it's unlikely to do much for your health.

If you're just curious to see what your own brain (liver, etc) looks like, you might want to volunteer for a study at a local university and ask them if you can get a copy of your own scan. I know one lab that will even show you how to 3D print your brain, if you want.