1. Department of Radiology, First Affiliated Hospital, Army Medical University, Chongqing 400038, P.R. China
2. Institute of Hepatopancreatobiliary Surgery, First Affiliated Hospital, Army Medical University, Chongqing 400038, P.R. China
3. Northwestern Quantitative Imaging Core Lab, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA