the scanners are usually not technically x-ray, some are mm wave, some are xray backscatter.
the technology can see through clothes and produce a grainy bw image of a naked person
the tech is very closed, and the customers are NDA'd into not letting the public know anything
the enhanced privacy changes don't change the device - its still taking naked pictures of people, its just doesn't show them to the operator.
before you look, as of a couple years ago there are just about 6 images from these devices out there on the internet.
(iirc, there is a researcher who bought one off of ebay to study, but lost track of their work. )
its in use in border patrol type operations to see into the trailers, trucks and cars.
no one can prove they aren't keeping a database of naked people. ;-)