Abstract:

Objective    To study the dynamic enhancement changes of necrosis of VX2 tumors with gray-scale contrast enhancement. Methods    16 VX2-bearing rabbits were randomly classified into group A and group B. SonoVueTM (0.1mL/kg) was applied by intravenous bolus injection 10 to 12 days after implantation in group A and 18 to 20 days in group B. The contrast enhancement of liver tumors between the two groups was analyzed using low mechanical index contrast gray-scale imaging. Results    Contrast-enhanced ultrasonography with low mechanical index (MI) gray-scale imaging clearly delineated dynamic enhancement of liver parenchyma and tumors. Compared with liver parenchyma, all tumors in group A showed hyperechoic enhancement in arterial phase and hypoechoic enhancement in portal and delayed phases. The enhancement of the tumors in group B was similar to that in group A. The necrotic area in the center of the tumors in group B showed hypoechoic enhancement in all phases, while the peripheral area without necrosis showed dynamic enhancement. Conclusions    Contrast-enhanced ultrasonography with low MI level can accurately show the scope of tumor necrosis, which may be useful in evaluating curative effect on liver tumor.

Key words:  Ultrasonography; Contrast agent; Liver; VX2 tumor; Rabbits