Researchers are working on improving the images produced by ultrasound in order to facilitate more accurate diagnoses. New advancements in ultrasonography include three- and four-dimensional ultrasound, which provide images that are almost as detailed as a photograph. They can facilitate detection of birth defects during pregnancy, breast abnormalities in younger women, whose breast tissue tends to be denser, and various other health conditions. In addition, advances in Doppler ultrasound techniques can help reveal increased blood vessels that may be associated with a mass or tumor. Power Doppler is a newer technique that is able to obtain images that are difficult or impossible to obtain using standard Doppler techniques. Power Doppler can provide greater detail of blood flow, especially in vessels that are located inside organs. These technologies are now available in some medical facilities and physicians’ offices.