1. From the Center for Biomedical Imaging Research, Department of Biomedical Engineering, Room 109, School of Medicine, Tsinghua University, Haidian District, Beijing 100084, China (H. Qi, H. Qiao, S.C., X.P., Y.W., X.Z., R.L., C.Y., H.C.); Philips Research China, Shanghai, China (Z.Z.); and Department of Radiology, University of Washington, Seattle, Wash (J.S., C.Y.).