目的 评价MRI对不同类型产前胎 盘植入的诊断价值以及MRI各征像的诊断 效能。方法 回顾99例疑胎盘植入患者的 影像、临床资料，病理结果以及术中诊断 为金标准，比较不同类型胎盘植入的产前 MRI表现差异，分析并总结MRI各征像的诊 断效能。结果 MRI诊断产前胎盘植入的 准确率为74.7%，诊断粘连型、植入性、 穿透型胎盘植入的准确率分别为73.6%、 90.9%、93.9%；胎盘植入的MRI各征象 中：子宫基质层低信号消失、胎盘内多发 迂曲流空信号影、子宫肌层局限性变薄、 中断、胎盘局限性膨隆、子宫下段肿胀， 植入组与非植入组差异具有统计学意义(P 值均小于0.05)。结论 MRI具有较高特异 性，胎盘内多发迂曲流空信号影、肌层局 限性变薄、中断、胎盘局限性膨隆、子宫 下段肿胀为具有诊断价值的征象，其中子 宫基质层低信号消失诊断价值较高。

Objective To evaluate the diagnostic value of MRI in different types of prenatal placenta and the diagnostic efficacy of MRI image. Methods The imaging and clinical data of 99 cases with suspected placenta implant were reviewed. The pathological results and the intra-operative diagnosis was used as gold standard. The prenatal MRI findings of different types of placenta were compared and the diagnostic efficiency of MRI signs was analyzed. Results The accuracy of MRI diagnosis of placenta implant was 74.7%, The accuracy of diagnosis of adhesion, implantation and penetration of placenta were 73.6%, 90.9% and 93.9%, respectively. Among the MRI signs of placenta implant, the low signal disappearance of uterine matrix layer, multi-circuity and flow void in placenta, thinning of the myometrium focally and interrupted, placental ectasia focally, the swelling of the lower uterine segment, the statistical differences was found between the implanted and non-implanted groups (all P<0.05). Conclusion MRI has high specificity, multi-circuity and flow void in placenta, thinning of the myometrium focally and interrupted, placental ectasia focally，swelling of the lower segment of the uterus are valuable diagnostic signs. Among those, the diagnosis value of the low signal disappearance of the uterine matrix is the most valuable.