How to prepare a kid of 2.5 year old for MRI with sedation? Only fasting for 3hours is enough?

A. I think Dr is going to tell you how do you need to proceed with fasting and all because the doctors can tell you the exact time for how much fasting you would require and you just have to prepare your child by telling that it is just a small test that they are going to do so they are just going to give you a medicine so that you sleep for a while and comfortably so that they can do the test so you just have to prepare your mind by saying these little little things and probably the child would be ready because once they get the child is unconscious for a while and it’s easier for them to conduct an MRI