Lars J Grimm1, Terry S Desser2, Janet E Bailey3, Charles M Maxfield4. 1. Department of Radiology, Duke University Medical Center, Durham, North Carolina. Electronic address: lars.grimm@duke.edu. 2. Department of Radiology, Stanford University Medical Center, Stanford, California. 3. Department of Radiology, University of Michigan Health System, Ann Arbor, Michigan. 4. Department of Radiology, Duke University Medical Center, Durham, North Carolina.