The US did have full body x-ray machines post-911. The name for them was backscatter. They did cause increased cancer rates, because they were ionizing radiation.

The priority back then was on airplane safety. 911 did some really weird shit to American society, including authorizing a mass indefinite detention and torture system. Back then waterboarding was being debated in civil society as a humane way of extracting information.

Famous intellectual Christopher Hitchens infamously aligned himself with the rightwing neocons and thought that waterboarding wasn't torture and that it wasn't a big deal. He agreed to have himself waterboarded to put his beliefs to the test, and immediately after 1 waterboarding session lasting just seconds he flipped his mind and started calling it torture. He was one of the only people ever to to try it, and it must have changed at least some minds in broader society.

If you weren't around back then you wouldn't really understand. The country lost its marbles entirely. You'd think America was normal prior to Trump, but no it wasn't.

I don't know if they're still in service today, but it's always worth asking.

https://en.wikipedia.org/wiki/Backscatter_X-ray

Here's the video of Hitchens agreeing to being waterboarded.

https://www.youtube.com/watch?v=4LPubUCJv58