[1] Univ Med Ctr, Dept Radiol, D-93053 Regensburg, Germany
[2] Univ Med Ctr, Dept Internal Med 2, D-93053 Regensburg, Germany
[3] Univ Med Ctr, Dept Epidemiol & Prevent Med, D-93053 Regensburg, Germany
[4] Donaustauf Hosp, Ctr Pneumol, Donaustauf, Germany
[5] Dalhousie Univ, Dept Radiol, Halifax, NS, Canada
[6] Addenbrookes Hosp, Dept Radiol, Cambridge CB2 2QQ, England