[1] Univ Erlangen Nurnberg, Dept Cardiol, D-91054 Erlangen, Germany
[2] Montreal Heart Inst, Montreal, PQ H1T 1C8, Canada
[3] Kings Coll London, Div Imaging Sci & Biomed Engn, London WC2R 2LS, England
[4] Univ Virginia Hlth Syst, Dept Med, Charlottesville, VA USA
[5] Univ Virginia Hlth Syst, Dept Radiol, Charlottesville, VA USA
[6] Univ Zurich Hosp, Dept Radiol, CH-8091 Zurich, Switzerland
[7] Uppsala Univ, Akad Sjukhuset, Uppsala, Sweden
[8] Univ Maryland, Sch Med, Dept Diagnost Radiol & Nucl Med, Baltimore, MD 21201 USA