The scan uses a low dosage of reflected x-ray radiation and penetrates only a few inches beneath the skin. Displayed images show objects near the body surface. A feature on the device allows inspectors to zoom in on a hidden object to determine if it is contraband. Not all passengers are scanned. Those singled out for search are offered the choice of a pat down or body scan.
Customs inspectors conduct a scan after receiving written permission from the passenger.
The scan is conducted in a private area. Pregnant women, or women who suspect they're pregnant, are not scanned. Same sex officers trained in radiation safety and the proper use of body imaging perform the scans. If you plan to ride the rails, you will find differing sleeping arrangements on Amtrak depending on the side of the Mississippi River. On routes west of the Mississippi you'll find larger accommodations including family bedrooms.