A new computerized image processing system was developed and applied clinically for three-dimensional visualization and volume calculation of cardiac structures, which were recorded in more than seven original two-dimensional echocardiograms in parallel planes. Three-dimensional display of this series of original two-dimensional echocardiograms was performed automatically using an overlaid display with different gray levels designating depths. The limitation of the present study was in the recording of original two-dimensional echocardiograms in parallel planes.