目的 探讨低机械指数诊断超声及低声压治疗超声对造影剂微泡的作用效果。方法 低机械指数的诊断超声及不同声压下低能量治疗超声体外辐照造影剂微泡,通过获得的超声造影图像间接分析微泡总浓度的变化,探讨不同机械指数诊断超声及不同声压治疗超声下微泡发生稳定空化及惯性空化情况。结果 低机械指数(<0.2)诊断超声及低声压(<0.15 MPa)治疗超声下微泡以稳定空化为主,随着机械指数增高或声压增高,微泡以稳定空化和惯性空化两种方式并存,当机械指数>0.3或声压>0.2 Mpa时,微泡以惯性空化为主。结论 微泡在低机械指数及低声压作用下发生不同空化效应,随着机械指数或声压增加,微泡破坏增加,以惯性空化效应为主。

Objective To investigate the effect of low mechanical index diagnostic ultrasound and low acoustic pressure therapy on contrast agent microbubbles. Methods Microbubbles were irradiated by diagnostic ultrasound with low mechanical index(MI) and low energy therapy under different acoustic pressure. To obtain the images, and analyze the change of microbubble concentration,the movement trend of microbubbles under different MI and different acoustic pressure were analyzed, to estimated stable cavitation or inertial cavitation of microbubbles. Results Stable cavitation was the main form of microbubbles under low mechanical index (< 0.2) diagnostic ultrasound and low acoustic pressure (< 0.15Mpa). With the increase of mechanical index or acoustic pressure, stable cavitation and inertial cavitation coexisted. When mechanical index > 0.3 or sound pressure > 0.2MPa, microbubbles were mainly inertial cavitation. Conclusion The cavitation effects of microbubbles under low mechanical index and low acoustic pressure are different. With the increase of mechanical index or acoustic pressure, the damage of microbubbles increases, and main effect is the inertial cavitation.