目的 探讨MR对胎盘植入产前治 疗方案选择的应用价值。方法 回顾性分 析29例确诊为胎盘植入的产前MRI图像， 观察指标包括胎盘植入部位、胎盘植入 附着面的最大径线D1、D1与胎盘最大径 线D2比值D1/2、胎盘植入部位T2WI低信号 影距离子宫肌层的长度L1、L1与胎盘厚度 L2比值L1/2及胎盘植入部位T2WI低信号基 底宽R。针对子宫切除与否，采用Fisher 精确概率检验、独立样本t检验和ROC曲 线对各参数进行统计学分析。结果 胎盘 植入部位(P=1.000)、基底宽R(t=1.08， P=0.299)对子宫切除与否的均数比较 差异不具有统计学意义；D1(t=4.44， P=0.001)、D1/2(t=6.04，P=0.000)、 L1(t=5.05，P=0.000)、L1/2(t=4.77， P=0.000)两者之间均数差别具有统计学意 义，子宫切除的临界值分别为72.75mm、 0.205、17.50mm、0.409，其相应ROC曲 线下面积(AUC)分别为0.922、0.956、 0.944、0.917。结论 MR对胎盘植入产前 治疗方案的选择具有一定参考价值。

Objective To explore that the predictive value of quantification parameters on MRI for optional treatment of the prenatal placenta increta. Methods The prenatal MRI findings of 29 patients were retrospectively evaluated, which were surgically diagnosed as placenta increta. The Quantification Parameters included the placental implantation site, the largest length of the placenta implantation area (D1), the ratio of D1 and the maximum length of placenta (D2), the distance of T2-hypointense to the surface of myometrium (L1), the ratio of L1 and placenta thickness (L2), and the basic width of T2-hypointense, Which were analyzed by Fisher exact test, Independent T-test and receiver operating characteristics (ROC) curves to aim at whether to resect uterus. Results The placental implantation site (P=1.000) and the basic width of T2-hypointense (t=1.08, p=0.299) were statistically insignificant between hysterectomy or not, respectively. While D1 (t=4.44, P=0.001), D1/2 (t=6.04, P=0.000), L1 (t=5.05, P=0.000) and L1/2 (t=4.77, P=0.000) were statistically different between hysterectomy or not, respectively. When the Youden index reached the highest point, the optimal threshold of D1, D1/2, L1 and L1/2 values were 72.75mm, 0.205, 17.50mm and 0.409, the corresponding area under the ROC curve (AUC) were 0.922, 0.956, 0.944 and 0.917 respectively. Conclusion The results provided evidence that MRI may have certain value for optional treatment of the prenatal placenta increta