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