1. Department of Medical Physics and Biomedical Engineering, UCL Centre for Medical Image Computing, and the Wellcome/ EPSRC Centre for Interventional and Surgical Sciences, University College London, London, U.K
2. Centre for Medical Imaging, University College London, London, U.K
3. Division of Medicine, Centre for Medical Imaging, University College London, London, U.K
4. Department of Electrical Engineering, City University of Hong Kong, Hong Kong, China
5. School of Biomedical Engineering and Imaging Sciences, King’s College London, London, U.K