产前MRI特征性征象诊断胎盘植入

目的 探讨产前MRI特征性征象诊断胎盘植入的价值。方法 回顾性分析163例拟诊胎盘植入孕妇的MRI资料，根据剖宫产手术结果，将其分为胎盘植入组（n=136）或无胎盘植入组（n=27）。比较两组间MRI征象的差异；以手术结果为金标准，计算其诊断胎盘植入的敏感度、特异度、阳性预测值及阴性预测值。结果 两组间子宫局部膨隆、胎盘内异常血管影、胎盘-子宫肌层结合面T2WI低信号带、胎盘局部凹陷征差异均有统计学意义（P均< 0.05）；胎盘内信号不均匀、子宫肌层不连续、子宫穿透及宫旁植入、胎盘组织突入子宫颈管差异均无统计学意义（P均> 0.05）。子宫穿透及宫旁植入、胎盘局部凹陷征、胎盘组织突入子宫颈管诊断胎盘植入的特异度、阳性预测值均为100%。结论 产前MRI诊断胎盘植入的效能较高，当出现子宫穿透及宫旁植入、胎盘局部凹陷征、胎盘组织突入子宫颈管时，应高度怀疑胎盘植入。

Characteristic prenatal MRI signs in diagnosis of placenta accreta

Objective To explore the value of prenatal MRI signs in diagnosis of placenta accreta. Methods MRI data of 163 pregnant women with suspected placenta accreta were retrospectively reviewed. According to the results of cesarean section, they were divided into placenta accreta group (n=136) or without placenta accreta group (n=27). The differences of MRI signs between the two groups were compared. Taking cesarean section results as the gold standard, the sensitivity, specificity, positive and negative predictive value of MRI signs were calculated, respectively. Results Uterine bulging, abnormal vessels and hypointense T2WI bands at junction of placental and myometrium, as well as uterine recess had statistical differences between the two groups (all P < 0.05). No statistical difference of placental heterogeneity, focal interruptions in myometrial wall, uterine penetration and parametrium implantation nor protrusion of placenta into cervix was found between the two groups (all P > 0.05). The MRI signs of uterine penetration and parametrium implantation, uterine recess, protrusion of placenta into cervix yielded a specificity and positive predictive value of 100%, respectively. Conclusion Prenatal MRI has high efficacy in the diagnosis of placenta accrete. Placenta accrete should be highly suspected especially in the presence of uterine penetration and parametrium implantation, uterine recess and protrusion of placenta into the cervix.