1. Duke University Medical Center, Department of Radiology, DUMC Box 3808, Durham, NC 27710, USA
2. Duke University Medical Center, Department of Surgery, Division of Urologic Surgery & Duke Prostate Center, DUMC Box 2804, Durham, NC 27710, USA
3. Duke Cancer Institute, DUMC Box 3494, 20 Duke Medicine Circle, Durham, NC 27710, USA