Question: Why are MRI scans so loud and big?

Gill Harrison answered on 27 Jan 2019:

MRI is basically big magnets inside a large metal coil. When the current is switched on the very strong magnetic field causes the coil to expand and contract creating a sort of vibration, this is why you hear loud clunks and other noises. It’s a good idea to ask if they will play some music then you’re having an MRI scan (some units will let you take your own music)