[1] Ninewells Hosp, Dept Clin Radiol, Dundee DD1 9SY, Scotland
[2] Univ Dundee, Ninewells Hosp, Sch Med, Div Imaging Sci & Technol, Dundee DD1 9SY, Scotland
[3] Univ Dundee, Ninewells Hosp, Tayside Med Sci Ctr TASQ, TCTU, Dundee DD1 9SY, Scotland
[4] Ninewells Hosp, Dept Med Phys, Dundee DD1 9SY, Scotland
[5] Univ Dundee, Div Populat Hlth Genom, Dundee DD2 4BF, Scotland
[6] Aberdeen Royal Infirm, Dept Clin Radiol, Aberdeen AB25 2ZN, Scotland
[7] Royal Free London NHS Fdn Trust, Royal Free Hosp, London NW3 2QG, England
[8] Ninewells Hosp, Dept Clin Pathol, Dundee DD1 9SY, Scotland