[1] Univ Bologna, Sez Radiol, Dipartimento Sci Radiol & Istocitopatol, Bologna, Italy
[2] Univ Florence, Sez Radiodiagnost, Dipartimento Fisiopatol Clin, Florence, Italy
[3] Univ Parma, Sez Radiodiagnost, Dipartimento Sci Clin, I-43100 Parma, Italy
[4] Ist Nazl Tumori, I-20133 Milan, Italy