目的探讨胎盘异常在MRI检查中 的不同表现及测量子宫下段肌层厚度， 为临床选择不同的分娩方式提供可靠依 据。方法 回顾性分析2016年1月-2017年 8月经临床手术和术后病理确诊胎盘植入 及先兆性子宫破裂的患者183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 1.MRI诊断粘连型、植 入型、穿透型胎盘符合率分别为76％， 94％，100％，诊断敏感性82.4％，特异 性81.0％。2.判断子宫前壁下段厚度的 MRI诊断正确 83.6％，误诊16.4％，对 于先兆子宫破裂敏感度89.2％，特异性 100％。3.副胎盘2例、巨胎盘1例、葡萄 胎盘1例。结论 MRI检查对孕妇产前评估 胎盘植入类型及子宫下段肌层的厚度，可 准确识别胎盘植入深度、部位、范围并有 利于指导及发现先兆子宫破裂，为临床 提供有效的手术方式，具有较高的推广价 值。

Objecitve To explore the different manifestations of placental abnormality in MRI examination and to measure the thickness of the lower segment of the uterus, it provides a reliable basis for clinical selection of different delivery methods. Methods The clinical data of 183 patients with clinical and postoperative pathologic confirmed placental implantation and threatened uterine rupture between January 2016 and August 2017 were retrospectively analyzed.MRI routine was performed to summarize the diagnostic results and MRI imaging findings. Results 1.MRI diagnosis of adhesion type, implantable type and penetration type placenta is 76%, 94%, 100%, diagnostic sensitivity 82.4% and specificity 81.0%. 2. It was found that the MRI diagnosis of the thickness of the anterior wall of the uterus was 83.6%, misdiagnosis 16.4%, and the sensitivity of the precursors was 89.2% and the specificity was 100%. 3. Two cases of placenta, one in the giant placenta and one case of grape placenta. Conclusion MRI examination was used to assess the type of placenta implantation and the thickness of the lower segment of the uterus, accurate identification of placenta implantation depth, location, scope and beneficial guidance and discovery of aura rupture, It provides effective operation method for clinical practice and has high promotion value.