超声造影对大鼠胎盘组织结构的影响

Effects of contrast-enhanced ultrasonography on placental hemodynamics and structures

目的观察超声造影对大鼠胎盘血流循环动力学及组织结构的影响。方法随机选择妊娠晚期(孕期18～21天)的Wistar大鼠30只,分为3组(每组10只),A组:对照组,注射生理盐水2.0ml/kg;B组:高剂量造影剂组,注射剂量为23.6mg/kg(2.0ml/kg,11.8mg/ml);C组:低剂量组,注射剂量为0.236mg/kg(2.0ml/kg,0.118mg/ml)。采用AcusonSequoia512超声诊断仪,其具有对比脉冲系列(CPS)超声造影技术,机械指数(MI)设为0.23。从孕鼠尾静脉注射造影剂或盐水,后在造影模式下辐照10min,造影完毕后立即取胎盘组织行显微及超微结构检查。结果A、C组中的10只胎盘均未见明显显微和超微结构变化,B组10只胎盘未见明显显微结构变化,但滋养细胞胞浆可见溶酶体数目增多,内质网扩张,糖原沉积和空泡。结论在低机械指数条件下行大鼠胎盘超声造影对胎盘绒毛组织不会产生明显的显微结构损伤,但对胎盘绒毛滋养细胞亚细胞器会产生超微结构损伤。

Objective To observe the change of placental ultrastructure following contrasvenhaneed ultrasonography in the late trimester of pregnant rat. Methods Thirty pregnant rats in late trimester of pregnancy were divided into three groups randomly： group A as control group with injection of normal saline solution （2. 0 ml/kg）, group B as high dose with injection 23.6 mg/kg body weight （2.0 ml/kg, 11.8 mg/ml and group C as low dose with injection 0. 236 mg/kg body weight （2.0 ml/kg, 0, 118 mg/ml）. The placenta of every maternal rat was examined by ACUSON Sequoia 512 with con trast pulse sequencing （CPS） technology. The machine index was set to 0.23. Contrast agent SonoVue or normal saline so lution was injected from the tail vein. Tissue slices of the placenta of pregnant rats in each group were collected for micro- structure and ultramicrostructure investigation after operation. Results Pathologic change was not found in placenta of three groups with microscope. There was no significant ultramicro-changes of the placenta in group A and group C with e- lectron scope. Cytolysosome increase, glycogen deposition, enlargement of rough endoplasmic reticulum, and vacuolization in the cytoplasm of glycogen deposition were found in group B. Conclusion Under low mechanical index, microstructure of syncytiotrophoblasts will not be damaged, but change of subcellular organelle in the syncytiotrophoblasts occurs.