A metal attache case containing a portable X-ray machine capable of causing radiation sickness and third-degree burns was taken from a physician's car parked at the Woodmont Country Club Tuesday night, Montgomery County police said.

The X-ray gun, or lixiscope containing a radioactive isotope, poses a health hazard to anyone who handles it and is exposed to the radiation for an extended period of time, said Ray Feldman of the Maryland Department of the Environment. In addition to radiation sickness and third-degree burns, exposure to the machine may lead to genetic mutations or cancer in the long run, he said.

Police said they have no suspects and that the thief or thieves probably did not know they had taken the cylindrical, steel-encased device resembling a science fiction space gun because it was enclosed in a case.

The gun is 18 to 24 inches long and about six inches in diameter. At the end of the cylinder is a handle shaped like the butt of a pistol and a trigger, police said.

The device is used to X-ray feet and hands and exposes the patient to one-quarter of the radiation of a standard X-ray machine, Feldman said. When the trigger is pulled an image of the bones shows up on a small screen in the cylinder, and if done repeatedly over several hours the recipient of the radiation could become sick and suffer burns, Feldman said.

"You don't want to expose yourself to any unnecessary radiation," Feldman said. Even those getting X-rays for medical reasons should decide if it is worth the risks of radiation exposure, he said.

Ken Wieselman, president of Healthmate Inc., which sells lixiscopes and a newer version called a fluoroscope, said, for example, if the gun were directed at a person's hand long enough it could cause redness and sores and could lead to amputation.

"Our concern is that in the wrong hands it could be dangerous," Feldman said. He added that children might see it as a Star Wars-type toy.

If a person ate the isotope inside the gun's chamber "it could really hurt them," Wieselman said. "I don't think they'd be around long."

The doctor who owned the lixiscope used it in minimal-incision foot surgery. It was in his car while he was playing golf and dining at the country club off Rockville Pike, just south of Rockville, he said. He asked that his name not be used.

The physician said he had the instrument in his 1982 Porsche 911 because he needed it for four operations the next day in one of his other offices. Usually it is kept in a locked closet, he said.

The device is often used in sports medicine to make an immediate, sideline diagnosis of athletes' injuries, Feldman said.

Six months ago the fluoroscope was developed, in which the isotope is replaced with a miniature X-ray tube, making it safer and more powerful so it can X-ray thighs and shoulders instead of just hands and feet, Wieselman said.