MRI量化指标对产前胎盘植入选择治疗方案的预测价值

The Predictive Value of Quantification Parameters on MRI for Optional Treatment of the Prenatal Placenta Increta

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D_1、D_1与胎盘最大径线D_2比值D_(1/2)、胎盘植入部位T2WI低信号影距离子宫肌层的长度L_1、L_1与胎盘厚度L_2比值L_(1/2)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;D_1(t=4.44,P=0.001)、D_(1/2)(t=6.04,P=0.000)、L_1(t=5.05,P=0.000)、L_(1/2)(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（D_1）, the ratio of D_1 and the maximum length of placenta（D_2）, the distance of T2-hypointense to the surface of myometrium（L_1）, the ratio of L_1 and placenta thickness（L_2）, 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 D_1（t=4.44, P=0.001）, D_（1/2）（t=6.04, P=0.000）, L_1（t=5.05, P=0.000） and L_（1/2）（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 D_1, D_（1/2）, L_1 and L_（1/2） values were 72.75 mm, 0.205, 17.50 mm 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.