Contrast enhanced ultrasound in diagnosis of hepatocellular carcinoma (HCC): role of wash-out in portal and late phases - Leoni, S; Piscaglia, F; Vidili, G; Gianstefani, A; Sagrini, E; Costantini, S; Golfieri, R; Bolondi, L (Ultraschall in der Medizin - European Journal of Ultrasound, 2008)