1School of Biomedical Engineering and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China, People's Republic of, 2Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, China, People's Republic of, 3Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 4Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 5Philips Healthcare, Guangzhou, China, People's Republic of