1. Tsinghua University, Department of Biomedical Engineering, Haidian District, Beijing 100084, China
2. National University of Singapore, Department of Biomedical Engineering, Singapore 117576, Singapore
3. Tsinghua University, Department of Biomedical Engineering, Haidian District, Beijing 100084, ChinacTsinghua University, Center for Biomedical Imaging Research, Haidian District, Beijing 100084, China