A brain MRI can be incredibly helpful. You should likely premedicate (I usually take Zantac/Zyrtec/a bit of hydrocortisone and have the doctor put some Benadryl in the IV sometimes). We are all different, of course, but without a history of anaphylaxis, and with your doctors reassurance that they are prepared to deal with that should it occur, it may be worth it to get those images.