目的 探讨磁共振成像(MRI)对前 置胎盘的诊断价值，为评估预后而提供依 据。方法 回顾性分析58例前置胎盘患者 的临床资料，其中26例前置胎盘患者并发 胎盘植入；对所有患者进行MRI及超声检 查，并分析对比MRI及超声检查对前置胎 盘的诊断符合情况；将58例前置胎盘患者 是否并发胎盘植入进行分组，分为胎盘植 入组和对照组，对比两组患者的MRI影像 特征，分析前置胎盘并发胎盘植入的特异 性MRI影像特征。结果 MRI对前置胎盘的 诊断符合率为100%，未出现漏诊及误诊 的病例，超声对前置胎盘的诊断符合率 为79.31%，其中漏诊1例，误诊11例；MRI 与超声对前置胎盘的诊断符合率具有显著 性差异(P＜0.05)；胎盘植入组和对照组 的MRI影像特征对比，胎盘植入组和对照 组的子宫下段变形或局部隆起、T2WI像出 现低信号暗带、植入局部流空血管影增多 均具有统计学差异(P＜0.05)。结论 MRI 对前置胎盘的诊断价值显著大于超声，诊 断符合率高，且并发胎盘植入的患者具有 特征性MRI征象，有利于评估前置胎盘的 预后，为临床及时采取干预措施而提供依 据。

Objective To investigate the magnetic resonance imaging (MRI) of the diagnostic value of placenta previa, and provide the basis for assessing the prognosis. Methods Retrospective analysis of clinical data of 58 cases of patients with placenta previa, in which 26 cases of patients with placenta previa placenta accreta, all patients MRI and ultrasound, and the analysis and comparison of MRI and ultrasonography in the diagnosis of placenta previa compliance, the 58 cases of patients with placenta previa combined with placenta implantation whether grouped into placental implantation and control groups, comparing MRI imaging features two groups of patients, analytical specificity MRI imaging features of placenta previa placenta accreta. Results MRI in the diagnosis of placenta previa rate was 100.00%, of cases of misdiagnosis and missed diagnosis does not appear, ultrasound diagnosis of placenta previa rate was 79.31%, which missed 1 case misdiagnosed 11 cases. MRI and ultrasound of the former diagnosis of placenta previa compliance rate has significant difference (P<0.05). MRI imaging features of placenta accreta group and control group comparison, the lower uterine segment placenta implantation and control groups deformation or local doming, T2WI image appears low signal dark with implanted locally increased vascular flow void Movies were significant differences (P<0.05). Conclusion The diagnostic value of MRI for placenta previa was significantly greater than the ultrasound diagnosis rate, and patients with placenta accreta concurrent with characteristic MRI findings will help evaluate placenta previa prognosis for clinical interventions and provide timely basis.