自制高分子微泡超声造影机械指数与频率和峰值强度的相关性

Correlation between mechanical index and frequency with peak intensity in contrast-enhanced ultrasound with self-made polymer acoustic contrast agents

目的探讨兔体内自制高分子微泡CEUS机械指数和频率与峰值强度的相关性。方法采用单乳化法制备包裹全氟戊烷的嵌段共聚物微泡造影剂,固定其他超声扫描条件,对6只新西兰大白兔于机械指数0.04、0.09、0.17、0.34和超声频率3.5、5.0、6.5、8.0MHz下进行肾脏CEUS,分析机械指数和频率与峰值强度的相关性;静脉注射10倍造影剂量微泡,观察毒性反应。结果自制微泡平均粒径为(3.92±1.43)μm。兔体内峰值强度与机械指数呈正相关(r=0.99,P<0.05),与超声频率呈负相关(r=-0.93,P<0.05);静脉注射大剂量微泡后,未见明显毒性反应。结论采用自制高分子微泡作为造影剂对兔进行CEUS时,峰值强度与机械指数呈正相关,与超声频率呈负相关;微泡安全性良好。

Objective To explore correlation between mechanical index and frequency with peak intensity in CEUS of rabbit kidney with self-made polymer microbubbles as contrast agents. Methods The diblock copolymer microbubbles encapsulating perfluoropentane were prepared with single emulsification method. CEUS was performed with mechanical index of 0.04, 0.09, 0. 17, 0.34 and frequency of 3.5, 5.0, 6.5, 8.0 MHz, respectively, with the other condition being unchanged. The correlation between mechanical index and frequency with peak intensity were analyzed. The toxicity reactions of the animals were observed after intravenous injection of microbubbles of ten-fold dose for CEUS. Results The mean diameter of the sell-made microbubbles was （3.92± 1.43）μm. The peak intensity was positively correlated with peak intensity （r=0.99, P〈0.05） and negatively correlated with ultrasonic frequency （r=-0.93, P〈0.05）. After intravenous injection of large dose microbubbles, no obvious toxicity reaction was found in all the animals. Conclusion The peak intensity has positive correlation with mechanical index and negative correlation with frequency in CEUS of rabbit kidney using self-made polymer acoustic contrast agents that have great safety.