Some 2 million women in the U. S. have breast implants, most of them silicone. One of the problems, however, is that the implants can tear. Ordinary mammography often fails to detect even large leaks because they may be obscured by the opaque implant. Now, radiologists at the University of Pittsburgh's school of medicine have found that ultrasound can be more effective than X-rays in finding such leaks.
On a sonogram, the silicone inside the implant appears black because sound waves are bouncing off a homogeneous material. But silicone that has leaked reacts with neighboring tissue to form tiny bubbles, which show up as a characteristic pattern of white spots. "It looks like snow," says Dr. Kathleen Harris, who discovered the process and is director of breast imaging at University of Pittsburgh's Magee-Womens Hospital. Leaky implants are usually surgically replaced, at which time surgeons remove errant bits of silicone.