Department of Radiology, Medstar Georgetown University Hospital, Washington, DC, USA. Department of Diagnostic Radiology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA. University of California San Diego Health System, Department of Radiology, San Diego, California, USA. Department of Radiology, New York Presbyterian-Columbia University Medical Center, New York, New York. Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA. Liver Imaging Group, University of California San Diego, San Diego, California, USA.