Body scanners at Blue Grass Airport will replace metal detectors as the primary passenger screening method.

The "advanced imaging technology" scanners are being installed and workers are being trained this week.

Some passengers might go through them later this week, but the new machines should be fully operational at the Lexington airport by early next week, said Jim Fotenos, Transportation Security Administration spokesman.

He said most travelers flying out of Blue Grass Airport will go through the scanners, although metal detectors still might be used in some circumstances, such as to balance passenger lines.

The scanners use "automated target recognition" software to detect items, including those not made of metal, that might be concealed in or beneath a passenger's clothing.

Fotenos said that when the machines do not detect any anomalies, TSA employees will see only "OK" on a computer screen before them.

If the machine detects an unusual item on a passenger, the screener will see a generic outline of a human form — not the actual outline of the passenger's body — with a box indicating the part of the body where the anomaly is, he said.

"It's a pretty significant privacy enhancement" over detectors that show an image of the specific passenger, Fotenos said.

He said it's also an improvement over metal detectors, which sound an alarm but don't allow security workers to pinpoint immediately where the unusual item is.

"They can target a search quicker," he said.

The scanners, already in use at 140 airports nationwide, were installed at Louisville International Airport last week.

Karla Ward: (859) 231-3314.Twitter: @HLpublicsafety