Figure 1

CT of a large hepatic alveolar echinococcosis located in the right liver lobe, caudate lobe and left medial lobe in case 21. Axial CT of the arterial phase (a) demonstrates that the right hepatic artery is of mild invasion by the lesion. Axial CT of the portal venous phase (b) displays the invasion of right portal vein with severe involvement (hollow arrow). Axial CT of the delayed phase (c) reveals obliteration of the right hepatic veins (arrow), and invasion of the second porta hepatis (arrowhead). Sagittal reconstruction of the portal venous phase data (d) displays severe invasion of retrohepatic vena cava (hollow arrow). Coronal reconstruction of the portal venous phase data (e) indicates the invasion of the first porta hepatis (arrowhead). Three-dimensional reconstruction image derived from the portal venous phase data (f) shows the location of the lesion and the relationship between the lesion and hepatic artery, portal vein, hepatic vein and inferior vena cava. The three-dimensional reconstruction images from arterial phase (g) and from the portal venous phase (h and i) data reflect the relationship between the lesion and hepatic artery, portal vein, hepatic vein and inferior vena cava in multiple-angle views, respectively. Notes 1, lesion; 2, hepatic artery; 3, inferior vena cava; 4, abdominal aorta; 5, portal vein; and 6, hepatic vein.