MR体素内不相干运动成像对中晚孕期正常胎盘血流灌注的定量评价（英文）  

Quantitative Assessment of Normal Placental Perfusion on Second and Third Trimester Using IVIM Echo-planar MRI

作　　者：石慧[1,2] 孙庚喜[2] 李胜华[2] 艾斌 刘鸿圣 曾斯慧 刘金武[4] 全显跃[1] 

机构地区：[1]南方医科大学珠江医院放射科,广东广州510282 [2]南方医科大学附属何贤纪念医院放射科,广东广州511400 [3]广州市妇女儿童医疗中心影像科,广东广州510623 [4]广东省第二人民医院影像科,广东广州510317

出　　处：《中山大学学报（医学科学版）》2016年第3期462-468,共7页Journal of Sun Yat-Sen University:Medical Sciences

基　　金：广州市番禺区科技计划项目(2015-Z03-12);广州市医药卫生科技项目(20161A011113)

摘　　要：【目的】评价磁共振体素不相干运动(IVIM)成像定量测量正常妊娠胎盘血流灌注的价值。探讨正常中晚孕期胎盘血液灌注的变化规律。【方法】搜集54例因胎儿轻微先天性发育异常来进行磁共振检查的妊娠中晚期单胎孕妇,所有孕妇在1.5 T磁共振仪进行胎盘的IVIM-DWI成像来计算灌注分数,并通过彩色多普勒超声测量子宫动脉的搏动指数(PI)。54例孕妇依照不同的孕龄(GA)分为Ⅰ组(GA 24-26周)(n=14)、Ⅱ组(GA 27-33周)(n=25)、Ⅲ组(GA 34-40周)(n=15)。IVIM-DWI采用呼吸触发序列,b值设定为:0,10,30,50,70,100,150,200,500,800,1000 s/mm2。IVIM成像参数图,包括标准扩散系数(D)、灌注分数(f)和灌注扩散系数(D*)图通过PRIDE DWI tool软件选择双指数模式自动生成,2名医师分别使用Image J图像处理软件对IVIM的3个参数进行测量。利用组间相关系数(ICC)对观察者间一致性进行判断。3组间D、D*、f的比较采用单因素方差分析,采用线性回归分析灌注分数f与孕龄及子宫动脉搏动指数(PI)的相关性,计算Pearson相关系数。【结果】f(ICC=0.808,P<0.001)与D(ICC=0.881,P<0.001)都有良好的可重复性;D*(ICC=0.754,P<0.001)可重复性一般。单因素ANOVA方差分析结果显示不同孕龄组间f值(33.81±2.94),(29.41±2.70),(27.71±1.53)%的差异有统计学意义(P=0.000),D、D*值在3组间差异无统计学意义,三组孕周的D值分别为:(1.28±0.12)×10^(-3),(1.32±0.14)×10^(-3),(1.27±0.15)×10^(-3)mm2/s(P=0.591);D*值分别为:(80.82±9.86)×10^(-3),(81.33±12.55)×10^(-3),(81.28±10.30)×10^(-3)mm2/s(P=0.982)。f值与孕周呈显著负相关(r=-0.534,P<0.01)。妊娠中晚孕期子宫动脉PI的中位值为0.74,f值与子宫动脉PI值显著相关(r=0.833,P<0.05)。【结论】基于IVIM的灌注分数f值可以作为稳定可信的客观指标量化评价胎盘血流灌注,为不能使用磁共振造影剂的妊娠期妇女评价胎盘血液灌注提供了新的选择。f值与彩色多普勒子[Objective] To investigate the value of intravoxel incoherent motion （IVIM） diffusion weighted imaging （DWI） on quantitative assessment of normal placental perfusion. The secondary aim was to investigate whether placental perfusion changes with increasing gestational age in normal pregnancy during the second and third trimester. [Methods] The study population included 54 singleton pregnancies who underwent MR examination for some suspected minor congenital abnormality, uterine artery pulsatility index （PI） was measured by Doppler ultrasound and placental perfusion was measured by IVIM Echo-planar imaging at 1. 5T in whole placental regions for each woman. Fifty-four pregnancies were divided into three groups according to gestational age （GA） ： group Ⅰ： 22-26 weeks （n = 14）, Ⅱ ： 27-33 weeks （n = 25）, Ⅲ： 34-40 weeks （n = 15）. IVIM-DWI protocol： respiratory- triggered DWI with one set of 11 b-values： 0, 10, 30, 50, 70, 100, 150, 200, 500, 800, 1000 s/mm2. Maps of perfusion fraction （f）, pseudodiffusion coefficient （D＊） and standard diffusion coefficient （D） were generated automatically by using PRIDE DWI tool with bi-exponential fit, and then measured by two practitioners using image-post-processing software Image J. Reproducibility of parameters measurement were determined by interclass correlation coefficient （ICC）. Difference of Parameters （D, D＊, f） between three GA groups were compared by one-way ANOVA analysis. Regression analysis was used to examine the significance of the association between placental perfusionfraction（f） and GA and uterine artery PI values. [Results] f （ICC = 0.808 ,P 〈 0.001 ） and D （ICC = 0. 881 ,P 〈 0. 001） measurements demonstrated good reproducibility, while D ＊ （ICC = 0.754,P 〈 0. 001） measurement showed poorer reproducibility. One way ANOVA analysis showed that there wassignificant difference in famong three GA groups （33.81± 2.94）, （29.41± 2.70）, （27.71 ± 1.53）%, respectively

关 键 词：妊娠 胎盘 磁共振扩散加权成像 体素内不相干运动 灌注 子宫动脉多普勒 

分 类 号：R714.2[医药卫生—妇产科学] R445.2[医药卫生—临床医学]