Ultrasound is the only cardiac imaging modality that is non-invasive, portable, economical, and has good spatial and temporal resolution. 3-D ultrasound allows physicians to view the heart's complex structure in its entirety, and most importantly, it provides the most accurate measurements of the heart's size and function. We have developed hardware and software for quantitative 3D echocardiography. Our technology produces a model of the left ventricle from ordinary 2D echo images acquired with position information. This advance will increase clinical information while reducing the time and the sonographer skill level required to obtain necessary views of the heart