目的 对磁共振(MRI)检查胎盘 植入高危患者进行诊断结果及影像学表 现分析，为胎盘植入的MRI诊断提供理论 依据。方法 本组观察对象为2015年12 月-2016年12月于我院诊断的70例胎盘植 入高危患者，所有患者入组后均行常规 MRI检查，详细记录MRI图像分析结果，以 手术或病理诊断结果为金标准,分析MRI检 查胎盘植入以及粘连型胎盘、穿透型胎 盘、植入型胎盘三种分型的诊断敏感度与 特异性，分析部分患者MRI图像的影像学 表现。结果 胎盘植入MRI影像学表现主要 有子宫肌层与胎盘分界不清；局部子宫壁 变薄；T2WI图像显示胎盘内有黑条带信 号；子宫下部膨隆不齐；子宫与胎盘交界 面存在多发纡曲血管影；子宫壁与胎盘交 界处出血或血肿；膀胱壁中断；MRI诊断 无胎盘植入40例、粘连型胎盘植入6例、 植入型胎盘植入19例、穿透型胎盘植入5 例；手术或病理诊断无胎盘植入37例、粘 连型胎盘植入13例、植入型胎盘植入17 例、穿透型胎盘植入3例；总体胎盘植入 诊断敏感度为66.67%,特异度为83.78%， Youden指数为0.50，粘连型胎盘植入诊 断敏感度为46.15%,特异度为98.25%， Youden指数为0.44，植入型胎盘植入诊 断敏感度为82.35%,特异度为90.57%， Youden指数为0.73，穿透型胎盘植入诊 断敏感度为66.67%,特异度为95.52%， Youden指数为0.61。结论 MRI检查胎盘植 入高危患者具有多种特征性影像学表现， 对于植入型胎盘植入具有较高的诊断敏感 度，MRI可用于高危患者胎盘植入的初步 诊断。

Objective To analyze the diagnostic results and imaging findings of high risk patients with placenta accreta by magnetic resonance imaging (MRI), and to provide theoretical basis for MRI diagnosis of placenta accreta. Methods The objects of this study were 70 patients with high risk of placenta accreta diagnosed in our hospital from December 2015 to December 2016, all patients underwent routine MRI examination after selection, and the results of MRI image analysis were recorded in detail. The diagnostic sensitivity and specificity of three types of placenta accreta, namely adhesive placenta, penetrating placenta, and implanted placenta, were analyzed by using results of MRI or pathological diagnosis as the gold standard. The imaging findings of MRI in some patients were analyzed. Results The MRI imaging findings of placenta accreta mainly showed that the unclear demarcation between myometrium and placenta, and the thinning of local uterine wall. T2WI images showed there were black stripes in the placenta, the lower part of the uterus was bulging, the uterus and placenta interface had multiple tortuous vascular, and bleeding or hematoma happened at the junction of the uterine wall and placenta, and bladder wall were interrupted. There were 40 cases of placenta free accreta, 6 cases of adhesive placenta accreta, 19 cases of implanted placenta accreta and 5 cases of penetrating placenta accreta diagnosed by MRI. There were 37 cases of placenta free implantation, 13 cases of adhesive placenta accreta, 17 cases of implanted placenta accreta and 3 cases of penetrating placenta implantation diagnosed by pathological diagnosis. The overall diagnostic sensitivity of placenta accreta was 66.67%, with a specificity of 83.78%, the Youden index was 0.50. The sensitivity, specificity and Youden index of adhesive placenta accreta were 46.15%, 98.25%, 0.44, respectively. The diagnostic sensitivity of implanted placenta accreta was 82.35%, specificity was 90.57%, and Youden index was 0.73. The diagnostic sensitivity, specificity and Youden index of penetrating placenta accreta were 66.67%, 95.52%, 0.61, respectively. Conclusion High risk patients with placenta accreta by MRI has a variety of characteristics of imaging findings, MRI has higher diagnostic sensitivity for implanted placenta, and can be used for the preliminary diagnosis of placenta accreta in high-risk patients.