目的 探讨磁共振成像(MRI)与 经腹彩超在产前诊断胎盘植入(PIA)中的 应用价值。方法 回顾性分析2015年5月 至2017年5月我院行MRI及超声产前检查 的孕妇70例，对比两种检查影像特点， 分析MRI及经腹彩超对其诊断效能，并对 比MRI及经腹彩超诊断子宫前后壁胎盘植 入的灵敏度、特异度及准确度，分析PIA 与非PIA患者MRI典型影像特征。结果 经 腹彩超显示胎盘处肌层侧血流丰富，层 次欠连续性，胎盘周围间隙消失，胎盘 下血管增多，MRI检查可见胎盘不均匀性 增厚，形态不规则，信号不均匀，局部 血管增多，与子宫壁分界不清，T2WI呈 低信号；MRI诊断PIA的灵敏度86.84%、 特异度90.63%、准确度88.57%明显高于 经腹彩超(P＜0.05)；MRI诊断子宫后壁 胎盘植入的灵敏度、特异度明显高于经 腹彩超(P＜0.05)；PIA患者胎盘下血管 增多、胎盘T2低信号、子宫局限性膨 隆等影像征象发生率高于非PIA患者(P ＜0.05)。结论 MRI与经腹彩超相比，对 PIA有较高诊断价值，尤其在后壁胎盘植 入诊断中有明显优势。

Objective To explore the application value of magnetic resonance imaging (MRI) and transabdominal color Doppler ultrasound in prenatal diagnosis of placental implantation abnormality (PIA). Methods 70 cases of pregnant women treated with MRI and ultrasound prenatal examination in our hospital from May 2015 to May 2017 were retrospectively analyzed. The imaging features of the two examinations were compared, and the diagnostic efficacy of MRI and transabdominal color Doppler ultrasound were analyzed, and the diagnosis sensitivity, specificity and accuracy of anterior and posterior uterine wall placental implantation were compared, and the typical imaging features of MRI in PIA and non PIA patients were analyzed. Results There was the abundant blood flow in the placenta muscle side, not enough layer continuity, the disappeared placenta peripheral space and the increasing placental vessels shown in the transabdominal color Doppler ultrasound. There were the uneven thickening placenta with irregular shape, uneven signal, increasing local blood vessels, unclear boundary with the uterus wall and low signal in T2WI shown in the MRI examination. The sensitivity, specificity, accuracy of MRI for PIA with 86.84%, 90.63% and 88.57% respectively were higher than those by transabdominal color Doppler ultrasound (P<0.05). The sensitivity and specificity of MRI in the diagnosis of posterior wall placental implantation were significantly higher than those of transabdominal color Doppler ultrasound (P<0.05). The incidence rates of placental vascularity, low placental T2 signal, and local expansion of uterus and other imaging signs in the PIA patients were significantly higher than those in the non PIA patients (P<0.05). Conclusion Compared with abdominal color Doppler ultrasound, MRI has a higher diagnostic value in PIA, and especially has obvious advantages in the posterior wall placental implantation diagnosis.