[1] Kings Coll London, St Thomas Hosp, Div Imaging Sci & Biomed Engn, London SE1 7EH, England
[2] Kings Coll London, Dept Phys, London WC2R 2LS, England
[3] Univ Loughborough, Dept Math Sci, Loughborough LE11 3TU, Leics, England
[4] Univ Nottingham, Sch Chem, Nottingham NG7 2RD, England
[5] Delft Univ Technol, Dept Biotechnol, NL-2628 BL Delft, Netherlands
[6] CROmed Ltd, H-1047 Budapest, Hungary
[7] Semmelweis Univ, Dept Biophys & Radiat Biol, H-1094 Budapest, Hungary