肋骨和肺组织遮挡对高强度聚集超声生物学焦域的影响

Effect of ribs and lung blocking on biological focal region of HIFU

目的 探讨高强度聚焦超声 (HIFU)在犬肝组织中生物学焦域 (BFR)与肋骨和肺组织遮挡的关系。方法 将实验犬随机分为对照组和手术组 (n =10 ) ,手术组模拟行肋骨部分切除、肋膈角闭合术 (PCCAC) ;以 0 .8MHz、焦距 12 0mm、定点点打、声功率 2 2 0W连续照射两组实验犬肝右叶 90s ,对肝生物学焦域进行面积和体积测定及病理学检查。结果 超声显示手术组犬肝形成 (1.0 4± 0 .2 3 )cm2 回声增强区 ,对照组没有观察到回声增强区 ;肉眼下实验犬肝生物学焦域体积(3 .2 4± 0 .47)cm3 ,与对照组比较差异有显著性 (P <0 .0 5 ) ;对生物学焦域的嗜伊红染色证实其手术组犬肝生物学焦域的坏死程度明显增强 ,范围增大。结论 肋骨和含气肺组织的遮挡对HIFU破坏犬肝组织具有明显的负影响 ,行PCCAC后可以有效提高HIFU在肝脏治疗靶区内的有效能量 。

Objective To study the relation of biological focal region (BFR) of high-intensity focused ultrasound (HIFU) in dog livers and ribs and lung blocking.Methods The experimental dogs were randomly divided to control group and experimental group (n= 10 in each).The dogs in experimental group simulatedly underwent partial costectomy and costophrenic angle closure (PCCAC),continuously exposed for 90 s by HIFU with 0.8 MHz waves,120 mm focal distance,fixed-point exposure,and 220 W sound power.The BFRs were estimated and pathological examination was done.Results The enhanced areas at (1.04± 0.23) cm 2 were noted in dog livers of experimental group by ultrasound,but not found in dog livers of control group.The BFR at (3.24± 0.47) cm 3 were noted in dog livers of experimental group by naked eye with the difference being significant between experimental group and control group (P< 0.05).The HE stain conformed that necrosis extent and scope of the BFR were obviously increased.Conclusion The block of ribs and lung containing air had negative effect on the destruction of dog liver by HIFU.The efficient energy of HIFU in liver target areas could be increased after PCCAC,and attenuation of energy could be decreased.