"X-ray vision" aids medical diagnoses.

In 1988, with both interest and concern, Henry Fuchs watched his pregnant wife undergo her first amniocentesis, a medical test for possible abnormalities in their developing baby. He was struck by the apparent awkwardness of the procedure. A University of North Carolina at Chapel Hill computer expert specializing in what the public calls "virtual reality," Fuchs thought it could be done better by positioning the images inside the patient, showing the fetus in its proper location within the mother's body -- sort of like Superman's X-ray vision. Since then, he and colleagues have been developing systems that may revolutionize certain key medical diagnosis and treatment methods within 20 years. They believe their efforts, which are medical firsts, also could save money and shorten recovery time.

The scientists are marrying ultrasound and virtual reality technologies to create three-dimensional images. When physicians wear computer-linked. headmounted displays that resemble overgrown goggles, the effect is almost like having X-ray vision to look into the patient's body.

In their first application, those images will help physicians more accurately take needle biopsies of women's breasts that contain suspicious, possibly cancerous, lumps. The researchers have used them successfully with scores of artificial breasts and in experimental tests with several women previously diagnosed with benign breast cysts.

"Although we still have much work to do, I think this approach is promising because it is a more direct, natural, and intuitive way to view tumors, for example, or babies in three dimensions within the mother than having to interpret flat pictures on a two-dimensional video screen," Fuchs indicates. "We were inspired by amniocentesis as an application, but we switched to breasts for our first needle biopsy experiments because breasts are relatively simple and accessible structures that don't contain major blood vessels and are thus easier and safer."

Future systems may be applied to infants developing in the womb as well as internal organs like livers and gall bladders. The toughest task so far has been to create the proper views within the headmounted display images. They must combine the real world around the physician -- such as his or her hands and the patient -- with the computer-generated 3-D scenery like ultrasound images of the inside of the breast. Getting the technology to work with intestines and lungs will be a future challenge since sound waves pass far less readily through air and other gases than through semi-solid or liquid-filled organs such as the breast or womb.

Etta Pisano, a member of the Lineberger Comprehensive Cancer Center and chief of breast imaging at the university, points out that, while conventional ultrasound alone works well for breast biopsies, the task requires an enormous amount of training and skill. "It's a bit like standing behind a curtain and trying to move a BB around with a needle with only a video camera to guide you. Radiologists learn this complex motor task, but it will be so much easier when they can see what they are doing more directly This work, which is in its infancy, is requiring a lot of hardware, brain power, and years of effort. Still, it is exciting because, potentially, it will be incredibly useful in medicine."