1. Department of Radiology, University of California, Irvine Medical Center, Orange, CA 92868, USA
2. Department of Surgery, University of California, Irvine Medical Center, Orange, CA 92868, USA
3. University of California, Irvine School of Medicine, Irvine, CA 92697, USA
4. Department of Surgery, Long Beach Veterans Affairs Medical Center, Long Beach, CA 90822, USA