A system for presenting multiple parallel slices comprises a display for displaying ultrasound data comprising 3D Doppler data over time. A user interface defines a proximal plane and a distal plane within the ultrasound data that are parallel to one another. The proximal and distal planes define a region of interest (ROI). A signal processor automatically extracts at least two slices based on the ultrasound data within the ROI. The at least two slices are parallel with respect to each other and are displayed on the display.