1. Departments of Radiology (V.D.S., V.L., P.F., R.L., L.M.P., M.Z.), S. Orsola-Malpighi Hospital, University of Bologna, 40138 Bologna, Italy
2. Departments of Pathology (T.B.), S. Orsola-Malpighi Hospital, University of Bologna, 40138 Bologna, Italy