3-D Ultrasound

These three-dimensional images show five different embryos seven to ten weeks after conception. The images were created by obstetrician Harm-Gerd Blaas of Trondheim University Hospital in Norway and combine traditional ultrasound imaging with computerized calculations of the volume of an embryo. Blaas used ultrasound, which harmlessly penetrates the mother and the fetus, to produce cross-sectional views of the developing embryo. A computer then constructs three-dimensional images from the cross sections that can be viewed from any angle. The technique allows Blaas to observe both an entire fetus and its internal organs, including such structures as the brain's cerebral cortex, which at seven weeks is only about the size of a grain of rice. This technology may one day enable doctors at remote locations to detect problems early in a pregnancy and send the images via the Internet to a specialist for consultation. "With ultrasound," says Blaas, "we can follow the embryo as it grows, and record all the changes in size and shape."