【摘要】 目的探讨MRI对凶险性前置胎盘(PPP)与非凶险性前置胎盘(n PPP)及并发胎盘植入的诊断价值。方法搜集75例行MRI检查并经手术病理诊断为前置胎盘患者,绘制MRI诊断PPP及n PPP(1组)、PPP并胎盘植入(2组)以及n PPP并胎盘植入(3组)的ROC曲线,获得2、3组检查方法的敏感度、特异度及Youden指数。应用确切概率法分析比较PPP与n PPP发生胎盘植入的差异。结果 MRI诊断1组、2组、3组的ROC曲线下面积分别为0.859、0.817、0.509;MRI诊断PPP和n PPP发生胎盘植入的灵敏度、特异度、Youden指数、阳性及阴性预测值分别为77.8%、20.0%,85.7%、81.8%,0.635、0.018,96.6%、50.0%,42.9%、52.9%;比较PPP与n PPP发生胎盘植入差异具有统计学意义P(i)=17.237,P=0.000,<0.05。结论 MRI在诊断PPP与n PPP、PPP并胎盘植入方面具有较好的诊断效能。PPP合并胎盘植入的发生率高于n PPP。更多还原

【Abstract】 Objective To evaluate the value of magnetic resonance imaging( MRI) in the diagnosis of pernicious placenta previa( PPP),non-pernicious placenta previa( n PPP),and when they combine with placenta accreta. Methods we collected 75 women of late pregnancy diagnosed of placenta previa. All underwent MRI to monitor placental growth and were confirmed by clinical and pathology after delivery. We drew the ROC curve of MRI in diagnosing PPP and n PPP( group 1),PPP combined with placenta accreta( group 2) and n PPP combined with placenta accreta( group 3). We obtained the sensitivity,accuracy and Youden index ect. of the group 2 and 3 to evaluate the diagnostic value. We used the exact probabilities to compare the difference between PPP and n PPP when they combined with placenta accreta. Results The area under the ROC curve of group 1,2,3 diagnosed by MRI were 0. 859,0. 817,0. 509. The sensitivity,accuracy,Youden index,positive predictive value and negative predictive value of group 2( group 3) were as following: 77. 8%( 20. 0%) 、85. 7%( 81. 8%) 、0. 635( 0. 018) 、96. 6%( 50. 0%) 、42. 9%( 52. 9%). we compared the difference between PPP and n PPP when they combined with placenta accreta,the difference was statistically significant P( i) = 17. 237,P =0. 000 < 0. 05. Conclusion MRI has a good diagnostic efficacy in PPP and n PPP,PPP combine with placenta accreta.When combined with placenta accreta,the incidence of PPP is higher than n PPP type.更多还原