emma,
Just to add to what Bandersnatch_F said. The MRI will detect many things including, brain tumor, inner ear issues, sinus problems, as well as MS lesions and pinched nerves.
I had a brain MRI with and without contrast. I pretty much demanded that my GP persrcibed me one. That is because I was convinced I had MS and wanted the MRI to rule it out. Your doctor is probably doing the MRI not because he/she thinks you have anything sinister, but just to rule it out. The reason he/she is not performing a EMG, is because he/she probably does not think there is even the slightest chance you have ALS.
Remember that BFS is a diagnosis by exclusion, and most doctors will perform many test to exclude any nasty diseases just to cover thir butts, although they may be very certain that the tests will all come out normal. Some doctors are more aggressive than others, and therefore that is probably why some of us had MRI's, and some didn't. Also, I think many people on this board had EMG's because they demanded them for their own peace of mind, not because their doctor thought they needed them. My doctor prescribed a EMG to look for a pinched nerve or carpal tunnel, not to look for ALS. Also, please be very aware of the fact that MANY people here have had MRI's and none of them had any nasty disease show up on them.
One last thing if your wondering, contrast on a MRI is when they inject a dye into you that gives them a better look at your brain. I'm not an MRI expert, but the way I understand it is that the dye will help show contrast from normal and abnormal areas such as lesions on the brain that would be a sign of MS. Therefore, if they stick a needle into your arm and inject a dye, that is a MRI with contrast. A MRI without contrast is when they do not inject the dye.
