[1] Univ Roma La Sapienza, Policlin Umberto 1, Dept Radiol Oncol & Anatomopathol Sci, I-00161 Rome, Italy
[2] Univ Munich, Hosp Grosshadern, Interdisciplinary Ultrasound Ctr, Munich, Germany
[3] Catholic Univ, Policlin A Gemelli, Rome, Italy
[4] Osped Valduce, Como, Italy