Like you already know, the MRI will probably not show anything because our injuries normally are too microscopic to see on an MRI....however, its a good tool to rule out any further serious damage. Its more about eliminating the possibility of your injury being more severe. Dont be discouraged if its negative....like you said...you already know you are brain injured and your symptoms tell your doctors that as opposed to an MRI. The MRI will have earplugs available for you (but bring your own if you feel more comfortable with that). THey also provide you with earphones with music of your choice in a lot of them. The noise is definetly loud, but try and stay calm and still. I had mine 2 days after my accident and i already had sirens going off in my ears and 10/10 headache....it was awful and very painful...but the peace of mind knowing i didnt have a bleed was definetly worth the stress of the test. Good luck!