Figure 5.

A lesion diagnosed as well-differentiated hepatocellular carcinoma (HCC) (maximum diameter, 20 mm) in segment III was found in an 82-year-old male patient with chronic hepatitis C. (A) Axial T1WI image on a plain scan shows homogeneous hypointensity in the tumor. The pre-contrast ratio was 0.724. (B) On the arterial phase of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid magnetic resonance imaging (EOB-MRI) (25 seconds), the lesion is shown as an isointensity, with significant branched peripheral blood vessels. (C) On the portal phase of EOB-MRI (70 seconds), the lesion is shown as a hyperintensity compared with the surrounding background liver parenchyma. (D) The lesion shows as a homogeneous hypointensity (arrow) on the hepatobiliary phase. The boundary is not very clear. The post-contrast ratio was 0.468 and the EOB enhancement ratio was 0.646. (E) The targeted lesion appears as a well-defined, homogeneous, non-hyperechoic lesion on grayscale ultrasound (US), without a surrounding halo. (F) Using low mechanical index contrast imaging, the arterial phase and the portal phase of Sonazoid contrast-enhanced ultrasound (SCEUS) show hypervascular and isovascular areas, respectively, with a homogeneous pattern. (G) During the post-vascular phase, the lesion appears as slightly hypoechoic. (H) After switching to high mechanical index contrast imaging, the lesion is shown more clearly as a defective area during the post-vascular phase. The arrows seen in (A,B,C,D) and the arrowheads seen in (E,F,G,H) indicate the margin of the lesion.