When I had my MRI, it was when I was having an ongoing headache that felt at times like there was an axe=head imbedded in my brain, and at other times, like there was a big knife stuck in my head. The x-rays, Catscan and MRI I had showed nothing (well, nothing to cause the pain!). I finally went to my chiropractor (I'd tried him first, but it didn't seem to help and I was impatient), and he cleared things up in just two adjustments.