Make sure you use ear plugs and the earmuffs provided for double protection as certain makes of MRI machines can get loud.
What @Strawberryblonde said, except: 1) Buy (and bring) your own "MRI safe ear defenders", as the ones the hospitals provide are the equivalent of wearing a pair of Mickey Mouse ears for the scan. 2) Make sure the earplugs you wear are foam and properly (deeply) inserted.
@Sydney13 I've had 3 MRIs, one leg and two head scans all post T and I've never had a spike when I've used protection.
Got an MRI when I was at my worst. I used deeply inserted foam earplugs plus sleeping ear plugs that lay over them. Plus the ear muffs they provided.
@Marshall thanks for your comment! What do you mean by sleeping ear plugs? How did you put those on top of the foam plugs already inserted?