The Transportation Security Administration announced nine more U.S. airports that will receive body-scanning.
TSA security director Lee Kair said units will be fielded in the coming months at Fort Lauderdale, Florida; San Jose, California; Columbus, Ohio; San Diego; Charlotte, North Carolina; Cincinnati; Los Angeles; Oakland, California; and Kansas City.
They will join three machines going online Monday at Boston's Logan International Airport, and one being deployed next week at O'Hare International Airport in Chicago.
All are among 150 machines bought with money from the federal stimulus package signed by President Barack Obama last year. They join 40 machines already in use at 19 airports nationwide.
Both the new and existing machines will also now be in a primary position, meaning they will be the default screening equipment passengers face at a checkpoint.
The existing machines have been in a secondary position, being used only when a passenger failed a metal screening or posed some other risk factor.