1. Department of Urology and University of Washington School of Medicine, Seattle, Washington, USA.
2. Department of Emergency Medicine, University of Washington School of Medicine, Seattle, Washington, USA.
3. Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
4. Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, Indiana, USA.
5. Division of Urology, VA Puget Sound Health Care System, Seattle, Washington, USA.