The new scanner shows a passenger's physical contours but does not show details of a person's body. The scanner is still able to detect any hidden weapons or explosives.
The new scanners are being tested in Las Vegas, Atlanta and Washington, D.C.
If all goes well for two months, the TSA can install the software to 250 of the scanners nationwide at a cost of $2.7 million. The expansion will be limited to that because the software only works on machines produced by one of the two companies that make them.
The Associated Press contributed to this report.