[1] Humboldt Univ, Fac Med, Dept Radiol, D-13353 Berlin, Germany
[2] Humboldt Univ, Fac Med, Dept Gen & Transplantat Surg, D-13353 Berlin, Germany
[3] Humboldt Univ, Fac Med, Dept Gastroenterol & Hepatol, D-13353 Berlin, Germany
[4] Univ Frankfurt, Dept Intervent Radiol, D-6000 Frankfurt, Germany