[1] Univ Hosp South Manchester NHS Trust, Nightingale Ctr, Manchester, Lancs, England
[2] Univ Hosp South Manchester NHS Trust, Genesis Prevent Ctr, Manchester, Lancs, England
[3] Univ Manchester, Inst Populat Hlth, Ctr Imaging Sci, Manchester, Lancs, England
[4] Univ Cambridge, Dept Radiol, Sch Clin Med, Cambridge, England