摘要目的:通过超声微血管成像技术(microvascular flow imaging，MVFI)评估胎盘微循环情况，并探究胎盘微血管指数(microvascular index，MVI)与胎儿生长发育的关系。方法:连续入组2019年10-11月在北京协和医院常规就诊或自外院转诊的孕24～34周生长受限(fetal growth restriction，FGR)胎儿7例，按照1∶2孕周配比相同时期内正常胎儿14例作为对照组，共计21例纳入研究。应用二维超声测量胎儿生长参数及预估胎儿体重，观察胎盘回声并测量厚度；应用彩色多普勒血流显像评估子宫动脉搏动指数(uterine artery pulse index，UtA-PI)、大脑中动脉搏动指数(middle cerebral artery pulse index，MCA-PI)和脐动脉S/D。采用MVFI显示胎盘血流，并测量微血管指数。结果:采用MVFI观察对照组(14例)和FGR组(7例)胎盘，与对照组相比，FGR组胎盘常表现为增厚、回声不均，MVI下降，UtA-PI可出现增高。两组胎儿胎盘平均MVI差异有统计学意义( P＝0.044)。此外，随着胎盘厚度的增加，该处MVI数值整体呈下降趋势，但相关性差异无统计学意义( rs＝-0.35， P＝0.065)。MVI对于FGR的诊断具有更高的特异性(100%)。 结论:MVFI可以敏感地显示胎盘微循环情况，为胎盘灌注的定量评估提供了一种直接、简便的检查手段。

abstractsObjective:To evaluate the placental micro-vascular circulation by microvascular flowing imaging (MVFI) method, and to explore the clinical value of microvascular index (MVI) for the diagnosis of fetal growth restriction (FGR).Methods:A total of 21 fetuses at 24-34 weeks of gestation at the Peking Union Medical College Hospital from October to November 2019 were enrolled in this study, including 7 fetal growth restriction (FGR) fetuses, and 14 normal fetuses as control group. The fetuses of the two groups were matched according to the gestational weeks at the ratio of 1∶2. Fetal biometry parameters were measured and the placenta was observed by two-dimensional ultrasound.Uterine artery pulse index (UtA-PI), middle cerebral artery pulse index (MCA-PI), and umbilical artery S/D ratio were evaluated by color and pulse-wave Doppler. The placenta mico-circulation was displayed by the MVFI method and MVI was measured.Results:The study included 14 normal fetuses and 7 FGR fetuses. Compared with the control group, more placenta in the FGR group manifested as thickened and heterogeneous with decreased MVI and increased UtA-PI. There was statistically significant difference in placental mean MVI between two groups ( P=0.044). Besides, a trend towards significant negative correlation was observed between MVI and placenta thickness, although this was not statistically significant ( rs=-0.35, P=0.065). MVI had a higher specificity (100%) in the prediction of FGR. Conclusions:MVFI can display the micro-circulation of the placenta, and provide a direct and quantitative assessment method for placental perfusion.