目的:利用弥散-弛豫MRI联合技术,在PPROM和胎膜完整的妇女中,在极端早产前询问胎盘的产前变化,并将其与随后在足月分娩的对照组进行比较。
方法:观察性研究。
方法:第三级产科单元,伦敦,英国。
方法:病例:妊娠32周前自发分娩单胎妊娠的孕妇,没有任何其他产科并发症。
方法:足月分娩无并发症妊娠的孕妇。
方法:所有女性都同意进行MRI检查。使用分数各向异性对胎盘的扩散-弛豫MRI进行组合分析,组合的T2*-表观扩散系数模型和组合的T2*-体素不相干运动模型,为了提供与早产相关的详细胎盘表型。根据病例组中的女性在扫描时是否有PPROM或完整的膜进行亚组分析,并在交付延迟时进行。
方法:分数各向异性,表观扩散系数和T2*胎盘值,来自两个模型,包括分离快速流动和缓慢流动(灌注和扩散)隔室的组合T2*-IVIM模型。
结果:本研究包括23名早产妇女和52名足月分娩妇女。胎盘T2*在T2*-表观扩散系数模型中(p<0.001)和在T2*-IVIM模型的快速和慢速流动区室中(p=0.001和p<0.001)较低。这在胎膜组的早产前破裂中达到了比在胎膜完整组中更高的显著性水平。在即将分娩的病例中,灌注分数降低。
结论:胎盘扩散-松弛揭示了早产前胎盘的显著变化,在早产胎膜破裂的情况下效果更大。该技术的应用可以在早产前对组织病理学变化进行临床上有价值的询问。反过来,这有助于更准确的产前预测早产绒毛膜羊膜炎,从而有助于在最安全的分娩时间做出决定.此外,这项技术提供了一种研究工具,可以提高对体内早产相关病理机制的认识.
OBJECTIVE: To utilise combined diffusion-relaxation MRI techniques to interrogate antenatal changes in the placenta prior to extreme preterm birth among both women with
PPROM and membranes intact, and compare this to a control group who subsequently delivered at term.
METHODS: Observational study.
METHODS: Tertiary Obstetric Unit, London, UK.
METHODS: Cases: pregnant women who subsequently spontaneously delivered a singleton pregnancy prior to 32 weeks\' gestation without any other obstetric complications.
METHODS: pregnant women who delivered an uncomplicated pregnancy at term.
METHODS: All women consented to an MRI examination. A combined diffusion-relaxation MRI of the placenta was undertaken and analysed using fractional anisotropy, a combined T2*-apparent diffusion coefficient model and a combined T2*-intravoxel incoherent motion model, in order to provide a detailed placental phenotype associated with preterm birth. Subgroup analyses based on whether women in the case group had
PPROM or intact membranes at time of scan, and on latency to delivery were performed.
METHODS: Fractional anisotropy, apparent diffusion coefficients and T2* placental values, from two models including a combined T2*-IVIM model separating fast- and slow-flowing (perfusing and diffusing) compartments.
RESULTS: This study included 23 women who delivered preterm and 52 women who delivered at term. Placental T2* was lower in the T2*-apparent diffusion coefficient model (p < 0.001) and in the fast- and slow-flowing compartments (p = 0.001 and p < 0.001) of the T2*-IVIM model. This reached a higher level of significance in the preterm prelabour rupture of the membranes group than in the membranes intact group. There was a reduced perfusion fraction among the cases with impending delivery.
CONCLUSIONS: Placental diffusion-relaxation reveals significant changes in the placenta prior to preterm birth with greater effect noted in cases of preterm prelabour rupture of the membranes. Application of this technique may allow clinically valuable interrogation of histopathological changes before preterm birth. In turn, this could facilitate more accurate antenatal prediction of preterm chorioamnionitis and so aid decisions around the safest time of delivery. Furthermore, this technique provides a research tool to improve understanding of the pathological mechanisms associated with preterm birth in vivo.