Abstract: An ultrasonic diagnostic imaging system is provided for measuring the volume of a chamber of the heart or other organ or vessel. An ultrasonic transducer probe is used to scan the chamber with a plurality of spatially distinct scan planes. The pixels of the chamber volume of each scan plane are aggregated to provide a measure of the volume. In a preferred embodiment the chamber volume pixels are developed from Doppler signals from the fluid within the chamber, and are related to voxels within the chamber by weighting pixels in the scan planes in accordance with the voxel sampling afforded by the inter-plane separation.