No, I am not trolling. Please try to read comments more charitably instead of assuming malice. Yes, I was comparing skin dose to the annual limit for the whole body. Depending on what you count as skin, skin is 2-5% of an adult's mass. So it would take thousands of scans per year to exceed the dose limit. In other words, safe.

I know what a sievert is (your definition is incorrect) and I know different types of ionizing radiation affect different tissues differently. But the safety margin is so great (89,000!) that it would take a new mechanism of action for such a tiny dose of X-rays to cause disease.

Edit: Because you deleted your comment, other readers now have no clue what I responded to. :/