Why are mri scans so expensive?

Equipment&training: Mri scanners require liquid helium to keep them cool. They have to be cool in order to "super conduct" and generate the very strong magnetic field needed for the scan. So there is a lot of overhead to keep an MRI running - both in materials and labor. The interpretation of the studies is also quite complex and require years of training to become qualified to interpret.

Technology costs: In addition to the costs of helium, etc. To maintain a magnet, the upfront cost is massive. On average, over a million dollars, and many close to 2 mill.