Abstract: A three-dimensional imaging system for obtaining a three-dimensional image of an object being scanned ultrasonically comprises a source arrangement for sequentially transmitting ultrasonic energy toward the object in successive directions in a first scanning plane, followed by sequential transmission of ultrasonic energy toward the object in successive directions in successive scanning planes parallel to the first scanning plane, a detector arrangement for receiving reflected energy and converting the reflected energy to electrical signals, and a processor for processing the electrical signals to develop reconstructed image data of the object, the reconstructed image data comprising forward projections of the object into a left image plane and a right image plane to form left and right images, respectively, the left and right images forming a stereo pair for composite display by a display unit.