1. From the Departments of Radiology (F. Song, N.S., F. Shan, Z.Z., J.S., Y.S.) and Infectious Disease (H.L., Y.L.), Shanghai Public Health Clinical Center, No. 2501 Caolang Road, Jinshan District, Shanghai 201508, China; Department of the Principal's Office, Fudan University, Shanghai, China (Z.Z.); Cancer Center, University of Michigan, Ann Arbor, Mich (Y.J.); and Shanghai Key Laboratory of Molecular Imaging, Shanghai, China (Y.S.).