Lead lined bags to protect from X-Ray

My understanding is that the scanner operator can turn up the gain on the sensor but cannot turn up the X-ray dose.

Here's Kodak's current (2003) bulletin (which doesn't address that particular issue, but covers lead bags, what X-ray fog looks like, and other topics) on X-ray scanners and film--

http://www.kodak.com/global/en/service/tib/tib5201.shtml

One advantage of the lead bags is that at least some people actually associate them with photographic film, so the labelling on the bag may help you make your case for careful handling.

Matt