X-Ray power - medical vs airport

Whenever I look to see what is on the screen on the airport security x-rays it seems instant, very clear and bright, and reasonably easy to distinguish between everything, even if the objects aren’t obviously recognisable to my untrained eye.

But medical x-rays seem to always be dark, blurry, take ages to be ready, and often the doctors have trouble distinguishing things from each other.

Why the discrepancy? Why can’t medical x-rays be as useful as airport ones? Maybe it’s something to do with radiation or something…

I THINK (and this is only a wag) that airport scanners use higher-frequency radiation, which produces much sharper images but is also a lot more destructive to human tissue.