A while back I was talking about having an MRI after bi-lateral hip replacements. What I wrote at first was correct as it is apparently about which part of the body is being viewed on the MRI that is important. If it was my head then I would apparently be OK as the lower part of me would not go into the machine. I could not have the lower part of my body go through the machine because of the metal implants. Just wanted to clear that up and say that what my physiotherapist told me was absolutely correct. She just didn't specify why, where etc.