A method for determining a contour of an organ in an ultrasound image is performed by a processor in a base unit. The method includes detecting an organ within the ultrasound image; obtaining a centroid position for the organ; extending a set of radial lines from the centroid position beyond an expected organ boundary; determining cost values at candidate nodes on each radial line, of the set of radial lines, by applying costs along gradient vectors that are normal to a contour between adjacent nodes on different radial lines; and selecting a final organ boundary contour based on a cost function analysis of paths through the candidate nodes.