产前MRI在胎盘植入中的诊断价值

The diagnostic value of prenatal MRI in placenta invasion

目的:探讨MRI在产前胎盘植入(PI)中的诊断价值。方法:回顾性分析、总结52例经手术病理证实的PI患者的MRI资料,并分析比较抑脂-快速自旋回波序列(FS-TSE)T2WI与平衡式快速场回波序列(B-FFE)在显示PI征象中的差异。结果:52例PI中,胎盘粘连17例,胎盘肌层植入27例,胎盘穿透8例。直接征象:子宫蜕膜层低信号带模糊不清或连续性中断52例;子宫肌层局部变薄或连续性中断19例;膀胱壁见胎盘组织侵入4例;宫旁受侵1例。间接征象:胎盘内见不规则低信号条带影24例;子宫下段局部膨隆21例;子宫膀胱交界面模糊、消失或呈锯齿样改变11例;胎盘内出血3例;胎盘内血管影增粗增多12例。FS-TSE T_2WI与B-FFE在显示PI征象上差异无统计学意义(P>0.05)。结论:PI的产前MRI表现具有一定特征性;PI的MRI检查需综合采用不同扫描序列,FS-TSE T_2WI及B-FFE为最佳观察序列。

Objective：To explore the value of MRI in the prepartal diagnosis of placenta invasion（PI）.Methods：The MRI imaging data of 52 cases with placenta invasion proved surgically and pathologically were analyzed and summarized retrospectively and the difference between the TSE-T2 WI fat suppression and B-FFE sequences on the signs of placenta invasion was explored.Results：Placenta accreta was found in 17 cases,placenta increta in 27 cases,and placenta percreta in 8cases.The direct signs of PI were as follows：the bottom of decidual low signal being blurred or interrupted in 52 cases,myometrium becoming thinner or interrupted in 19 cases,bladder wall being invaded in 4cases,and parametrium being invaded in one case.The indirect signs of PI were as follows：dark intraplacental bands being observed on T2-weighted imaging in 24 cases,lower uterine segment bulging in 22 cases,the interface between uterus and bladder disappearing in 11 cases,the intraplacenta hemorrhage being found in 3cases,the intraplacenta vascularity becoming thickening and increasing in 12 cases.There was no statistical significant difference between T2 WI fat suppression and B-FFE sequence in the direct and indirect signs of placenta invasion（P〉0.05）.Conclusion：MRI has certain characteristics in the prepartal diagnosis of PI.It is necessary to combine the characteristics of different MRI sequences for the diagnosis of PI,with the FS-TSE T2 WI and B-FFE sagittal positions as the best sequences for observation.