Apple's iPhone 7 Plus decided to add another lense to be able to make better pictures. Meanwhile Walabot who started with wanting to build a breast cancer detection technology released a 600$ device that can look 10cm into walls. Thermal imaging also got cheaper.
I think it would be possible to build a 1500$ device that could combine those technologies and also add a laser that can shift color. A device like this could bring medicine forward a lot.
A lot of area's besides medicine could likely also profit from a relatively cheap 3D scanner that can look inside objects.
Developing it would require Musk-level capital investments but I think it would advance medicine a lot if a company would both provide the hardware and develop software to make the best job possible at body scanning.
Unfortunately, I don't think we have the regulatory regime to sell them to consumers. At least, not in the US and Europe, and not while making available any information on how the scanner might produce medically relevant data.
Another Musk-level capital investment might be needed to solve this hurdle.
Legally I think the scanner might not be allowed to tell you whether you have breast cancer but I think it might be allowed to show you a pretty 3D picture.