Relationship of different acoustic pressures and enhancement effects of contrast agent in ultrasonography on normal rabbit liver

Objective To assess the relationship of different acoustic pressures and enhancement effects using self-made lipid ultrasound contrast agents on normal rabbit liver parenchyma. Methods Self-made lipid ultrasound contrast agents were administered to 5 normal rabbits through ear veins at dose of 0.1 ml/kg. The acoustic pressures were divided into 9 different levels raging from 1 to 609 kPa.Each level was injected 10 times (every rabbit was injected 2 times ). We observed the enhancement of liver parenchyma and quantified the peak video intensity and enhanced time. Results The peak video intensity of liver parenchyma has no difference at acoustic pressures less than 56 Kpa. However, peak video intensity decreased gradually when acoustic pressures keep on increasing. There was no enhancement of liver parenchyma at acoustic pressure 609 kPa. Conclusion The changes of acoustic pressures at range of 1-56 kPa don't affect the contrast enhancement using self-made lipid ultrasound contrast agents. When acoustic pressures greater than 76 kPa the contrast enhancement will decrease obviously.