Figure 9d.

Infiltrative HCC as a differential diagnosis for confluent fibrosis in a man with HCV-related cirrhosis. Axial 3D T1-weighted gradient-echo images (~4/1.5, flip angle = 15°) (a–c) and 2D T1- and T2*-weighted gradient-echo image (180/6, flip angle = 70°) (d), obtained at 3 T after intravenous infusion of SPIO and before (a) and 20 seconds (b), 80 seconds (c), and 4 minutes (d) after intravenous injection of a gadolinium-based contrast agent, show a wedge-shaped conglomerate mass in the liver. The mass involves the entire right lobe, bulges the capsule, and expands the liver volume; it enhances heterogeneously on the arterial phase image (arrowheads in b). The dissipation of the contrast agent is nonuniform, causing the mass to have heterogeneous signal intensity in the late venous phase. The mass invades the right hepatic vein (white arrow in c) and a portal vein branch (black arrow in c). Although the wedge shape of the mass suggests a benign process, the volume expansion, nonuniform dissipation of contrast material, and delayed phase heterogeneity favor the diagnosis of carcinoma. Vascular invasion by the tumor, which was an HCC, clinches the diagnosis of malignancy.