[1] Kings Coll London, Div Imaging Sci & Biomed Engn, Rayne Inst, St Thomas Hosp, London SE1 7EH, England
[2] Pontificia Univ Catolica Chile, Sch Med, Dept Radiol, Santiago, Chile
[3] Kings Coll London, Wellcome Trust, London SE1 7EH, England
[4] Kings Coll London, BHF Ctr Excellence, London SE1 7EH, England
[5] Kings Coll London, NIHR Biomed Res Ctr, London SE1 7EH, England
[6] Kings Coll London, EPSRC Med Engn Ctr, London SE1 7EH, England