You take all metal clothes off like bra etc, they usually make you wear a gown,
You lie down feet facing the machine or if a breast mri then face down with your breasts in a hole which feels weird!!
Then they might give you a set of headphones to 'listen to music' which is usually shit or radio 2, you'll also get an emergency stop buzzer to press if you can't keep going.
Take a set of foam ear plug and ask if you can use these in the mri if they don't have the headphones as these helped me to drown out the noise.
Then they'll say what they're doing and that they're just in another room and to press the buzzer if you need them.
Then it'll start and it is loud, lots of banging and lots of whirring. Some mris have something on the inside to look at but that is rare, usually it's just scuffs or the plastic of the tube you can see.
Focus on a single point of something you can see and do steady breathing techniques like in for 2 hold for 2 out for 2 and repeat. I've made myself fall asleep before by doing that.
You might hear a woman's voice say 'take a breath in... hold......... breathe away' or they might not.
You might have contrast which is an injection in a cannula and it's very odd it feels like you've wet yourself but you haven't.