Soon after Marna Gold had a hysterectomy, she knew something was wrong, she was in pain and running a fever. That's when doctors discovered two surgical sponges - left inside her body after surgery. "It was a mistake, it was really a mistake."

Each year there are hundreds of cases where surgical items are mistakenly left inside patients. To prevent problems, hospitals do a manual count of sponges and other instruments at the end of each operation. Now, new technology is helping keep track.@

New York's Montefiore Medical Center is one of several hospitals using the RF Assure Detection System. Each sponge has a radio-frequency chip. Before the patient is stitched up, doctors wave a wand over the patient. The system alerts the staff if it picks up a signal. "Things can get hidden there and so this is a technology with the ability to add to our manual count," says Dr. Robert Michler.

Experts say while the new technology is useful, it's not a substitute for counting every sponge used during surgery. Diligence, they say, is essential in the operating room. "The surgeon has to do a wound examination before they begin to close and it's the surgeons job to get the sponges out or any other items," says Dr. Verna C. Gibbs of NoThing Left Behind Project.

Gold needed a second surgery to remove the sponges. "I was lucky because I did everything very promptly."

Doctors say waiting longer could have caused serious complications.