DWI评价正常中晚孕期胎盘成熟度的初步研究  

Primary study of DWI in evaluation of placental maturity in the second and third trimesters of pregnancy

作　　者：石慧 冯咏辉 姚青 李裕 曾斯慧 刘鸿圣 

机构地区：[1]广州市番禺区何贤纪念医院放射科,广东广州511400 [2]广州市妇女儿童医疗中心影像科,广东广州510623

出　　处：《实用放射学杂志》2017年第12期1883-1886,共4页Journal of Practical Radiology

基　　金：广州市医药卫生科技项目（20161A011113）.

摘　　要：目的 探讨MRI常规序列在中晚孕期胎盘成熟度分级的运用及胎盘表观扩散系数（ADC）与孕周的关系。方法 收集因B超疑诊母体其他疾病或胎儿畸形而进一步行MRI检查的单胎妊娠孕妇52例，依不同孕龄（GA）分为3组：Ⅰ组 GA 18～26周（n=29）；Ⅱ组 GA 27～33周（n=14）；Ⅲ组GA 34～40周（n=9）。在1.5T MRI仪行胎盘常规序列及扩散加权成像（DWI）扫描，包括2组不同扩散因子b值组合：0 s/mm2、200 s/mm2、800 /mm2及50 s/mm2、200 s/mm2、800 s/mm2，计算2组ADC值，用一元线性相关分析胎盘ADC值与孕周的关系。结果 半傅里叶采集单次激发快速自旋回波序列（HASTE）能清晰显示胎盘的3层结构并对成熟度进行分级判定。b值组合为0 s/mm2、200 s/mm2、800 s/mm2对应的ADC值与孕龄显著负相关r=-0.900，P＜0.001）；b值组合为50 s/mm2、200 s/mm2、800 s/mm2对应的ADC值与孕周并不相关（r=-0.037，P=0.795）。结论 MRI能够显示正常胎盘成熟进程的形态学变化。b值设为0 s/mm2、200 s/mm2、800 s/mm2时，胎盘ADC值随胎盘成熟呈下降的趋势。Objective To investigate the value of routine MRI in determining placental grading and the relationship between placental apparent diffusion coefficient （ADC） value and the gestational age （GA） in the second and third trimesters of pregnancy. Methods 52 women with singleton pregnancies were referred for MRI examination for underlying maternal or fetal lesions or malformations identified by ultrasound （US）. Subjects were divided into three groups according to the GA： group I at 18-26 weeks （n=29）; group Ⅱ at 27-33 weeks （n=14） ;group Ⅲ at 34-40 weeks （n=9）.DWI protocol included 2 sets of b-values：0 s/mm2 ,200 s/mm2 ,800 s/mm2 and 50 s/mm2 ,200 s/mm2 ,800 s/mm2 , and ADC values of the two groups were calculated and correlated with GA by simple linear regression.Results Half-fourier acquisition single-shot turbo spin-echo （HASTE） sequence could clearly define the 3 layers of placenta and determine the grading of placental aging. ADC values with b values of 0 s/mm2 , 200 s/mm2 and 800 s/mm2 were correlated negatively with GA （r=-0.900,P〈0.001）. However, ADC values with b values of 50 s/mm2 , 200 s/mm2 and 800 s/mm2 did not show any statistical correlation with GA （r=-0.037, P=0. 795）.Conclusion MRI can visualize the morphological changes of the placenta during the pregnancy. With a set of b-values at 0 s/mm2 , 200 s/mm2 and 800 s/mm2 , placental AIX3 values are found to have decreasing tendency as the pregnancies progress in the second and third trimesters.

关 键 词：胎盘 扩散加权成像 表观扩散系数 成熟度 

分 类 号：R714.1[医药卫生—妇产科学] R445.2[医药卫生—临床医学]