Correlation between blood circulation grading and angiogenesis using ultrasonic contrast of rabbit VX2 hepatic carcinoma

Objective: To build the rabbit model of VX2 hepatic carcinoma, examine the tumor body using the ultrasonic contrast and study the correlation between the blood circulation grading and angiogenesis. Methods: The VX2 tumor strain was prepared in the lateral muscle of the hind legs of 40 male New Zealand rabbits (which were purchased from Nanjing Senbao Biotech Co., Ltd.). The tumor block was embedded in the center of left liver lobe directly to build the rabbit model of VX2 hepatic carcinoma. The ultrasonic contrast was performed 14 d after implanting the tumor body. The semi-quantitative classification (0-IV level) was taken according to the blood flow of tumor vessel. Animals were executed using the air embolism method. The liver was separated to extract RNA and total protein respectively. The real-time PCR and western blotting method were employed to detect the expression of angiogenesis-related factors of VEGF, bFGF and TNP-alpha, while the ultrasonic contrast to detect the correlation with blood circulation grading. The Pearson product moment correlation coefficient was used to measure the linear relationship between these two variables and analyze the correlation between the blood circulation grading and angiogenesis using the ultrasonic contrast. Results: Thirty-three rabbits had the successful model of VX2 hepatic carcinoma. The blood circulation grading by ultrasonic contrast was: 2 cases at level 0 (6.60%), 5 cases at level I (16.7%), 12 cases at level 11 (40.0%), 6 cases at level III (20.0%) (local dense or clustered blood flow) and 5 cases at level IV (16.7%). The results showed that there was positive correlation between three angiogenesis-related factors and the blood circulation grading. The correlation coefficient between three angiogenesis-related factors and the blood circulation grading was over 0.9, which indicated the relatively high correlation. Conclusions: The ultrasound blood circulation grading for the hepatic carcinoma can clearly reflect the changes of blood vessel, which will be of critical significance for the early diagnosis of hepatic carcinoma and clinical evaluation of angiogenesis indicators.

Dynamic Assessment of the Focal Hepatic Lesion in Rats Using Ultrasonic Contrast Agent

The focal hepatic lesion caused by local injection of absolute alcohol in rats was evaluated with ultrasonic contrast agent and pathologic examination. Twenty adult Wistar rats weighing about 200 g were injected with absolute alcohol （0. 05-0. 1 mL each one） on the exterior left lobe of the liver under the monitoring of ultrasound. Pulse inversion harmonic imaging was used to evaluate the focal lesion after bolus injection of ultrasonic contrast agent （0. 05 mL/200 g） through caudal vein. Seven days later, the focal lesion was studied again as before. The exterior left lobe of liver with focal lesion was incised and underwent pathologic examination. The results showed that all of the focal lesions could be defined clearly after bolus injection of the ultrasonic contrast agent under the mode of pulse inversion harmonic imaging. There was good correlation between the size of the focal lesion measured by ultrasound on the 7th day after the ＂ablation＂ under the mode of pulse inversion harmonic imaging and that gotten by pathologic examination （P=0.39）. The focus size measured by ultrasound right after the ablation was larger than that gotten by pathologic examination （P=0. 002）. It was concluded that ultrasonic contrast agent plus pulse inversion harmonic imaging could be used to assess the size of the focal hepatic lesion caused by local injection of absolute alcohol in rats.