(FORTUNE Magazine) – The video camera long ago invaded the delivery room. Soon doctors using a novel ultrasound technology will invade the real inner sanctum to create three-dimensional images of the developing fetus quickly and easily. Besides improving today's grainy two-dimensional prenatal sonograms, doctors will use the new technology to examine the uterus, ovaries, and cervix. They'll even be able to see 3-D images of egg cells to be harvested for in vitro fertilization. The new technique is the brainchild of a team of scientists and physicians led by Kenneth Watkin, a biomedical engineer, at Montreal's McGill University. Vital Images of Fairfield, Iowa, is commercializing the technology using its own volumetric imaging software. The Montreal team has designed the system to be an add-on to conventional ultrasound gear, which typically costs about $130,000 and consists of a screen, a console, and sound-producing wands of various shapes. The new system's centerpiece is a powerful Silicon Graphics workstation with special imaging software; a motion-detecting sensor will clip onto the wand. Probable price: about $50,000. The technique will mimic the 3-D pictures of CAT scans and magnetic resonance imaging. CAT scanners work by taking hundreds of evenly spaced X- rays, each like a slice of cheese, as the X-ray source moves along an arc; a computer then assembles the slices into a solid block. The exam entails several minutes of X-ray exposure. The ultrasound procedure requires much less scanning time -- only a single 30- to 60-second pass of the wand across the mother's abdomen. And like conventional ultrasound, it won't expose the fetus to harmful radiation. As the technician slowly moves the wand, more than 100 crystals emit ultrasonic bleeps -- just like sonar pulses. Thirty times a second, the console combines the echoes to produce a two-dimensional image of what lies immediately below the wand, similar to a CAT-scan slice but with somewhat less resolution. (With conventional ultrasound, this is what you see on the screen.) At the moment they are taken, the slices are arrayed every which way, and the distance between them varies. But the clip-on sensor registers the wand's position at the instant of each sounding, letting the computer locate the images in space. When the exam ends, the computer shuffles all the data to create a solid model of the fetus. Doctors can then examine cross-sections from any angle or flip through the slices like a deck of cards. Processing time is about a minute. Caveat: The fetus must keep still. Testing of the system will begin at several hospitals later this year; it may be ready for market some time in 1994. And yes, parents will be able to take home a videotape showing a series of cross-sections that give solid form to the child, and get a head start on bonding with their baby.