I agree with Mark in that it doesn't sound like an MRI or CT scan would help (show anything) but for your peace of mind maybe have an MRI? I would.

I'd stay away from the CT scan though.

MRI's don't show everything either so as Sarah says it doesn't mean nothing is going on.

Don't know how long you've been suffering with this but I had the same problems for months and still do 17 months later, it sucks, I know. I used to hold my head when walking, now I'm so darned used to it!

Feel better...