1 Centre for Medical Image Computing, Department of Medical Physics & Biomedical Engineering, University College London, UK. Electronic address: c.veiga@ucl.ac.uk.
2 Centre for Medical Image Computing, Department of Medical Physics & Biomedical Engineering, University College London, UK.
3 Oncology, Guy's & St. Thomas' NHS Trust, London, UK; Division of Imaging Sciences, King's College London, UK.