The Gadolinium in the MRI contrast dye is removed almost entirely by the kidneys within 24 hrs. It should be safe if your kidney function is good. It’s recommended that you drink at least 8 glasses of water during the 24 hrs following the MRI. An IV of normal saline could be given but would require you to be retained in the hospital or imaging center during the infusion and it would probably be deemed not medically necessary. Your insurance company would likely deny coverage for the IV and time of administration. The goal is adequate hydration afterward which can be accomplished by drinking fluids. You might discuss your concerns with your physician, and I would bet he/she will allay your fears about the contrast.