[1] Natl Inst Med Res, London NW7, England
[2] Univ Aberdeen, Dept Biomed Phys & Bioengn, Aberdeen AB9 2ZD, Scotland
[3] NINCDS, Neuroradiol Sect, Bethesda, MD USA
[4] Aalto Univ, Low Temp Lab, FIN-02150 Espoo, Finland
[5] UCL, Dept Med Phys, London, England
[6] Max Planck Inst Biophys Chem, D-37077 Gottingen, Germany
[7] Eurat ITAL, Wageningen, Netherlands
[8] Univ Coll N Wales, Inst Mol & Biomol Elect, Bangor LL57 1UT, Gwynedd, Wales
[9] MRC Cyclotron Univ, Hammersmith Hosp, London, England
[10] Univ Texas, Syst Canc Ctr, Dept Phys, Houston, TX USA
[11] Juravinski Canc Ctr, Hamilton, ON L8V 5C2, Canada
[12] McMaster Univ, Hamilton, ON L8V 5C2, Canada