Fair points, but my thinking was more for cases here in the US where insurance may or may not cover an MRI of your choice for something like torn rotator cuff,

Fair points, but my thinking was more for cases here in the US where insurance may or may not cover an MRI of your choice for something like torn rotator cuff, or where you'll end up paying your full out of pocket maximum for it. Cheaper options in such cases would be welcome.