1. Departments of Medical Physics and Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA.
2. Department of Radiology, Maastricht University Hospital, Post Office Box 5800, 6202 AZ Maastricht, Netherlands.
3. Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Broadway Research Building, Room 779, 733 North Broadway, Baltimore, MD 21205, USA.
4. Departments of Radiology and Chemical and Biomolecular Engineering, Johns Hopkins University School of Medicine, 217 Traylor Building, 720 Rutland Avenue, Baltimore, MD 21205, USA.
5. Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Broadway Research Building, Suite 643, 733 North Broadway, Baltimore, MD 21205, USA.