Objective:To explore the feasibility and mechanism on changing acoustic environment in tissue (AET) of rabbit liver by HL-1 intravenous injection.Methods:10 New Zealand rabbits were randomly divided into two groups

treatment and control group with 5 rabbits respectively.Before rabbit livers were ablated in vitro by using focused ultrasound(FU)(3.04W

11MHz)

HL-1 was injected intravenously via rabbit ear marginal vine for 20 minutes.Rabbits were sacrificed by excessive anesthesia after 1 hour

and small pieces of liver tissue were cut for pathological exammation.Rabbits liver were ablated with FU in the manners of dot scan in different preplanned liver areas with various treatment time of 3s

6s

9s

12s and 15s

and its temperature in each dot was measured immediately after ablation.2 to 3 pieces of non-damaged tissues in each liver were chosen to measure its density after trial.All processes were the same as those of experiment group except replacing HL-1 with saline in control group.Results:Similar time-temperature curve showed in two groups except the temperature was higher in every dot in treatment group than that of control group( P <0.05).Pink

tumidity and lipid deposition were seen in the liver of treatment group.Pathological exammation showed augmentation

swelling and disorders of hepatocytes in treatment group;hepatic sinusoids and central vein of liver shrunk evidently.“Consolidation configuration” appearance was found in tissue section.Abundant liposome deposited in hepatocytes and sinusoids and accumulated in sinusoids in treatment group.The densities of liver tissues were 1.1217±0.0281 g.cm -3 and 1.0547±0.0388g.cm -3 ( P <0.01) in treatment and control group respectively.Conclusion:HL-1 can accumulate massively in rabbit liver and change its AET by intravenous injection

which can enhance the deposition of ultrasonic energy in target tissue and speed up temperature rising.