探讨高危孕妇胎盘植入的临床危险因素及MRI价值征象

目的探讨高危孕妇胎盘植入的临床危险因素及MRI价值征象。方法91例高危孕妇,年龄23~44岁、平均年龄32岁;孕周27~38.5周、平均孕周36.2周;分别分析临床资料及MRI宫内征象1)胎盘异常增厚及胎盘内T2WI低信号带;2)胎盘与肌层分界线不连续或中断;3)子宫肌层变薄及局部膨隆。最终诊断结果均经手术及病理证实。采用卡方检验比较临床高危因素及MRI宫内征象在总体胎盘植入与对照组间以及MRI宫内征象在胎盘植入组内的统计学差异。结果41/91例为胎盘植入,其中26例浅植入(胎盘粘连)、13例胎盘深植入、2例胎盘穿透,余50例阴性。临床资料剖宫产和/或流产史次数大于等于2次、前置胎盘以及上述MRI宫内征象在总体胎盘植入组间均具有统计学差异(P<0.05)。其中胎盘T2WI低信号带(P=0.015)、胎盘与肌层分界线不连续或中断(P=0.007)、子宫肌层变薄(P=0.000)及局部膨隆(P=0.006)在胎盘植入组内具有统计学差异。结论剖宫产和/或流产史次数大于等于2次及前置胎盘是高危孕妇胎盘植入的临床危险因素。上述MRI宫内征象均为高危孕妇胎盘植入的价值征象。其中胎盘与肌层分界线不连续或中断,是胎盘浅植入的敏感征象。除胎盘异常增厚外,余下MRI宫内价值征象出现越多,提示胎盘植入越深,危险性越大。

Investigation of the clinical risk factors and MR imaging features of placenta implantation in the high-risk pregnant women

Objective To investigate the clinical risk factors and MR imaging(MRI)features of placenta implantation in high-risk pregnant women.Methods 91 cases of high risk pregnant women,aged from 23~44 years(average 32 years)and gestation from 27~38.5 weeks(average 36.2 weeks)were studied.All the clinical data and the MRI features such as 1)placenta abnormal thickness and dark intraplacental band on T2-weighted images(T2WI);2)uncontinuity or interruption of placenta-myometrial interface,and 3)myometrium thinness and uterine bulging,were analyzed respectively.All the final diagnoses were confirmed by surgery and pathology.We compared statistical differences of the clinical risk factors and MRI manifestations between placenta implantation and the control group,and of the MRI manifestations within the placenta implantation groups by Chi-square test.Results 41 cases were proven to placenta implantation,including 26 cases with slight placenta implantation(placenta adhesion),13 cases with deep placenta implantation(placenta increta),2 cases with placenta percreta,and that the other 50 cases were negative.The clinical data such as two or more times of previous cesarean deliveries and/or abortion and placenta previa and all the MRI features had statistically difference between placenta implantation group and the control group(P<0.05).Dark intraplacental bad on T2WI(P=0.015),uncontinuity or interruption of placenta-myometrial interface(P=0.007),myometrium thinness(P=0.000)and uterine bulging(P=0.006)had statistically difference within placental implantation groups.Conclusion Two or more times of previous cesarean deliveries and/or abortion and placenta previa are the clinical risk factors and the above MRI features are the valuable features of placental implantation in high-risk pregnant women.The uncontinuity or interruption of placenta-myometrial interface is the sensitive feature of slight placenta implantation.In addition to placenta abnormal thickness,the more value features appear,the more depth of placenta implantation will increase,with risk increasing.