Sartor Agnès, Arthurs Owen, Alberti Corinne, Belarbi Nadia, Tilea Bogdana, Boizeau Priscilla, Oury Jean-Francois, Elmaleh-Berges Monique, Gressens Pierre, Sebag Guy, Alison Marianne
Service de Gynécologie-Obstétrique, Hôpital Robert Debré, AP-HP, Inserm UMR 676, Université Paris Diderot - Sorbonne Paris Cité, Paris, France.
Prenat Diagn. 2014 Apr;34(4):357-66. doi: 10.1002/pd.4309. Epub 2014 Feb 12.
The objective of this study was to determine the reproducibility, the inter-hemispheric difference and the reference apparent diffusion coefficient (ADC) values of the fetal brain according to gestational age.
One hundred and one normal fetal brain (29.4-38.4 weeks) were analysed with diffusion-weighted MR imaging. ADC was measured in frontal white matter (FWM), occipital white matter (OWM), centrum semi-ovale (CSO), basal ganglia (BG), cerebellar hemisphere (CBM) and pons. ADC ratios (fronto-occipital, fronto-cerebellar and occipito-cerebellar) were calculated. Inter-observer reproducibility was assessed on 27 studies, using intra-class correlation coefficient and Bland-Altman plot. Inter-hemispheric difference was evaluated with Bland-Altman plot. Gestation-specific reference intervals were estimated for each brain region.
Inter-observer bias was near zero. Limits of agreement (LOA) were clinically acceptable (-0.17; 0.20 to -0.38; 0.31 × 10(-3) mm(2) /s) for all brain regions except for CSO and pons. Inter-hemispheric bias was near zero. Smallest LOA were for FWM (±0.09 mm(2) /s) and BG (±0.019 mm(2) /s). ADC values decreased, whereas ADC ratio increased with gestational age, reflecting normal maturation. Fronto-occipital, fronto-cerebellar and occipito-cerebellar ratios were consistently above 0.8, 1 and 1, respectively.
The fetal brain regions with the highest reproducibility and smallest inter-hemispheric differences are the frontal, occipital, cerebellar white matter and BG. ADC ratio could be useful to assess differential temporo-spatial maturation.
本研究的目的是根据胎龄确定胎儿脑的可重复性、半球间差异以及参考表观扩散系数（ADC）值。
对101例正常胎儿脑（29.4 - 38.4周）进行扩散加权磁共振成像分析。在额叶白质（FWM）、枕叶白质（OWM）、半卵圆中心（CSO）、基底神经节（BG）、小脑半球（CBM）和脑桥测量ADC。计算ADC比率（额枕、额小脑和枕小脑）。使用组内相关系数和Bland - Altman图对27项研究评估观察者间的可重复性。用Bland - Altman图评估半球间差异。估计每个脑区的孕周特异性参考区间。
观察者间偏差接近零。除CSO和脑桥外，所有脑区的一致性界限（LOA）在临床上均可接受（-0.17；0.20至-0.38；0.31×10（-3）mm（2）/s）。半球间偏差接近零。最小的LOA见于FWM（±0.09 mm（2）/s）和BG（±0.019 mm（2）/s）。ADC值随胎龄降低，而ADC比率随胎龄增加，反映正常成熟过程。额枕、额小脑和枕小脑比率分别始终高于0.8、1和1。
可重复性最高且半球间差异最小的胎儿脑区是额叶、枕叶、小脑白质和BG。ADC比率可能有助于评估不同的时空成熟度。
