1. Division of Surgery & Interventional Science; University College London; Floor 9, Royal Free Hospital London NW3 2QG UK
2. UCL Centre for Advanced Biomedical Imaging, Paul O'Gorman Building; University College London; 72 Huntley Street London WC1E 6DD UK
3. Department of Tissue Engineering and Biophotonics, King's College London; Dental Institute-Central Office; Floor 18, Guy's Tower, Guy's Hospital London SE1 9RT UK
4. Department of Medical Physics and Biomedical Engineering; University College London; Malet Place Engineering Building, Gower Street London WC1E 6BT UK
5. Centre for Medical Image Computing; University College London; The Front Engineering Building, Floor 3, Malet Place London WC1E 7JE UK