不同分型穿透性胎盘植入的MRI特征

MRI Characteristics of Different Types of Penetrating Placenta Implantation

目的 分析不同分型穿透性胎盘植入的MRI特征。资料与方法 回顾性分析2017年5月—2020年5月于四川省人民医院就诊、经临床手术和(或)病理确诊的20例穿透性胎盘植入孕妇的产前MRI图像,分析不同分型的穿透性胎盘植入MRI特征:T2WI上胎盘内低信号带、胎盘内紊乱血管影、胎盘内信号不均匀、子宫下段增宽、胎盘-子宫交界面不清、胎盘凹陷征、胎盘局限性膨隆、胎盘向宫颈内口突出、膀胱血管征、子宫浆膜下血管征、膀胱帐篷征、膀胱壁中断、膀胱腔内肿块/结节,宫旁脂肪层内异常血管影。结果 20例穿透性胎盘植入中,3a级11例,3b级9例。胎盘内紊乱血管影和T2WI上胎盘内低信号带在穿透性胎盘植入3a级和3b级均较常见,胎盘-子宫交界面不清、胎盘内信号不均和子宫浆膜下血管征在3b级中较3a级常见,但两组患者MRI特征比较,差异均无统计学意义(P均>0.05),3a级患者胎盘厚度较3b级明显增厚[(5.18±1.22)cm比(4.53±1.93)cm;t=5.541,P=0.03]。结论 不同分级穿透性胎盘植入MRI表现有所不同,且穿透性胎盘植入尚未突破子宫浆膜面、侵犯膀胱时胎盘厚度明显增加。

Purpose To analyze the MRI characteristics of different types of penetrating placenta accreta. Material and Methods MR images of 20 pregnant women from May 2017 to May 2020 with penetrating placenta accreta confirmed by operation and/or pathology in Sichuan Provincial People’s Hospital were retrospectively reviewed, and the MRI manifestations of different types of penetrating placenta accreta were further analyzed. MRI features included intraplacental hypointensity zone on T2WI, intraplacental disorder vessel shadow,intraplacental signal unevenness, widening of lower uterine segment, unclear placenta-uterine interface, placental indentation sign, placental local swelling, placenta protruding into the internal mouth of cervix, bladder vessel sign, subserous uterine vessel sign, bladder tent sign,bladder wall interruption, intravesical mass/nodule, abnormal blood vessel shadow in the adipose layer beside uterus. Results Of 20 pregnant women with penetrating placenta accreta, there were 11 subjects with 3a grade and 9 subjects with 3b grade. The placental vascular shadow disorder and the placental hyposignal zone on T2WI were all commonly observed. The MRI features of loss of placenta-myometrium interface,the placental signal asymmetry, and subserous uterine vessel sign were more commonly identified in 3b grade than those in 3a grade, however,there were no significant differences in these MRI features between 3b grade and 3a grade. The placenta thickness of 3a pregnant women was significantly greater than those of 3b pregnant women [(5.18±1.22) cm vs.(4.53±1.93) cm;t=5.541, P=0.03]. Conclusion The different MRI features of penetrating placenta accreta were observed in pregnant women with 3a and 3b grade, and the placenta thickness was obviously increased without breakthrough uterus and bladder violation.