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