Just in case there is someone on this site who isn’t a Trekkie somehow: In Star Trek the all purpose device they use for scanning and other similar things is a Tricorder. One of the applications is medical. You scan someone with this and can get most of the info you might need to diagnose and treat conditions.

I recently had to get some rather invasive tests and it just got me wondering if such a thing is hypothetically possible in the future. What are the barriers that stop us from doing something like that for now/ever? We already have some tests that use waves to image parts of the body like X-rays or MRIs. Is it just complete fantasy to imagine such tests for other parts or functions of the body?

Edited to fix a typo and to clarify that I’m mostly talking about the part where they can remotely scan someone instead of having to stick something in or take something out. The miniaturization is cool, but kind of secondary. I’d take having to go to a doctor and sitting in the equivalent of an MRI machine if it meant not having to get poked and prodded.