I pay an extra $60 a year to have my ophthalmologist take a digital image of my retina. It comes back as normal every year, but if something does change we can diff the image against the baseline.

Maybe I don't want to look for cancer right now but if I spend $1,000 every 5 years to take an image for later use... isn't that useful?

Might be, but in the context it's also worth asking what better options you have for your health with that $1000.

(for some people that question may not apply, of course, but at a population level it does, and we have population-level questions about effective use of MRI time.). And if there's something better, you should spend it on that and then ask the question _again_. So it could be that getting a whole-body MRI is something like $30k down the list of best ways to spend money for improved health.

I'm not sure what the best use of $1k is from a health standpoint is, just noting that it's good to have a comparator.

Yes, and it seems like its purposefully ignored in the "body scan" debate. full CT scans would be more problematic, and MRI's (especially no contrast ones) don't pick up a lot of things... but having annual comparisons over a few years would likely fill in some of those gaps. literally and figuratively.

Er wait is retinal cancer a thing?