Signal intensity of the liver parenchyma in microbubble contrast agent in the late liver phase reflects advanced fibrosis of the liver.

BACKGROUND: Microbubble of Levovist accumulates in liver parenchyma, and the phenomenon has been reported as late liver-specific parenchymal. The aim of the present study was to compare the parenchymal enhancement effect of Levovist with the degree of liver dysfunction. PATIENTS AND METHODS: Sixty consecutive patients who consented to be treated were enrolled in this study. Pulse-inversion ultrasonography (US) in the liver parenchymal phase of enhancement with Levovist was performed in a preoperative examination. The mechanical index of pulse-inversion US was set at 1.3. The gray-scale intensity of the non-tumor area of the liver parenchyma at the level of the focal zone was measured. The hepatic fibrosis index was measured in each liver by morphometric analysis. The correlation between the gray-scale intensity of the non-tumor area of the liver parenchyma and the hepatic fibrosis index was assessed. RESULTS: There was a significant inverse correlation between the gray scale of the liver parenchyma and the hepatic fibrosis index (r = -0.809, P < 0.01). The average signal intensity of the liver parenchyma was 144.5 in a normal liver, 133.6 in chronic hepatitis, and 102.6 in liver cirrhosis, demonstrating a significant difference between a normal and cirrhotic liver (P < 0.01). CONCLUSIONS: The signal intensity of a microbubble disruption of the liver parenchyma in the late phase of enhancement with Levovist was considered to reflect the degree of hepatic fibrosis.