1. From the Department of Radiology and Biomedical Imaging, University of California, San Francisco, 513 Parnassus Ave, San Francisco, CA 94117 (M.M.O., C.A., A.S., Y.S., Z.J.W., B.M.Y.); and Department of Radiology, Albert Einstein College of Medicine, Montefiore Medical Center, New York, NY (J.Y.).