That part is harder than it seems, good quality imaging of many of those locations is hard with a body coil. So the fact you can physically fit a leg in, say,

That part is harder than it seems, good quality imaging of many of those locations is hard with a body coil. So the fact you can physically fit a leg in, say, doesn’t give you usable knee imaging. There also may be issues with the shape of the field if it is too tuned to cranial imaging, but the center should be pretty flat. I’m not saying it couldn’t work with a bunch of extra RF engineering, but it’s not a given. For that matter some locations mist don’t have very good mr imaging regardless of setup.