目的 探讨MRI鉴别前置胎盘不 同分型及胎盘植入的敏感性。方法 回顾 性分析2012年8月-2014年8月经临床手术 和术后病理确诊为前置胎盘患者24例临 床资料，均行MRI常规，总结诊断结果及 MRI影像学表现。结果 以临床手术和术 后病理为准，MRI诊断完全性前置胎盘、 部分性前置胎盘、边缘性前置胎盘的符 合率分别为93.33%、75.0%、100.0%；影 像学表现为胎盘组织覆盖完全或部分子 宫颈内口，或位于宫颈内口边缘。MRI诊 断粘连型、植入型、穿透型胎盘植入的 符合率分别为100%、75.0%、66.67%。诊 断敏感性78.57%，特异性为80.0%，影像 表现为胎盘-子宫分界中断或连续，胎盘 增厚，形态异常，内部信号异常；胎盘子宫分界中断或模糊。结论 MRI能够明确 前置胎盘和胎盘植入的类型，具有较高 的应用价值。

Objective To investigate MRI in identifying different types of placenta previa and the sensitivity of placenta implantation. Methods The clinical data of 24 patients with placenta previa confirmed by clinical operation and postoperative pathology from August 2012 to August 2014 were retrospectively analyzed. All of the patients underwent MRI routine. The diagnostic results and MRI imaging findings were summarized. Results Subject to clinical operation and postoperative pathology, The coincidence rates of MRI in the diagnosis complete placenta previa, part placenta previa and marginal placenta previa were 93.33%, 75.0% and 100.0%, respectively. The imaging findings showed that the placenta tissues covered the entire or part internal opening of the cervix, or at the edge of the internal opening of the cervix. The coincidence rates of MRI in the diagnosis of adhesive type, implantable type and penetrating placenta implantation were 100%, 75.0% and 66.67%, respectively. The diagnostic sensitivity was 78.57% and the specificity was 80.0%. The imaging findings showed that the placenta-uterine boundaries were interrupted or continuous, the placenta was thickened, the morphology was abnormal and the internal signal was also abnormal. The placenta-uterine boundaries were interrupted or obscure. Conclusion MRI can define the type of placenta previa and placenta implantation and has high application value.