产前开放性神经管缺陷修补术后胎儿脑MRI的T2高信号与ADC值
本研究回顾性分析49例胎儿在宫内开放性神经管缺陷修补术后约6周的MRI，发现71.4%胎儿存在T2高信号，且这些胎儿多数脑区ADC值较低，完全性后脑疝逆转率也较低（65.7% vs 100%），提示T2高信号与脑微结构改变或髓鞘化延迟相关。
要点
- 术后胎儿脑T2高信号常见（71.4%），需注意评估ADC值。
- T2高信号胎儿顶叶、颞叶、枕叶ADC值较低，提示微结构改变。
- 无T2高信号者后脑疝完全逆转率更高（100% vs 65.7%）。
关键影像表现/征象
- T2高信号定义为信号强度主观高于周围脑实质的区域。
- 后脑疝逆转定义为小脑见于枕骨大孔以上。
- T2高信号见于35/49（71.4%）胎儿。
局限性
- 单中心回顾性研究。
- 样本量有限（49例）。
- T2高信号定义主观。
以上解读依据论文摘要（全文未开放获取或许可不允许翻译转载）。
英文原文（摘要）· 点击展开
BACKGROUND AND PURPOSE: T2 hyperintensity on fetal brain MRI is frequently observed in fetuses with an open neural tube defect (ONTD) and may reflect edema, impaired CSF circulation, or altered brain maturation. By characterizing the diffusion of water molecules within brain tissue, DWI may help differentiate among these etiologies by assessing water diffusion as a marker of brain microstructure. Our aim was to investigate the relationship between brain T2-hyperintensity and ADC values in fetuses following prenatal ONTD repair.
MATERIALS AND METHODS: We retrospectively analyzed fetal MRI scans performed 6 weeks after in utero ONTD repair at a single center. T2 hyperintensity was defined as a region with signal intensity subjectively higher than that of the surrounding brain parenchyma. ADC values were measured in the frontal, temporal, parietal, and occipital lobes on axial brain DWI sequences (b=700 s/mm2). Hindbrain herniation was evaluated, and reversal was defined when the cerebellum was seen above the foramen magnum. ADC values were compared between fetuses with and without T2 hyperintensity using the Mann-Whitney U test. A P value < .05 was considered significant.
RESULTS: Forty-nine fetuses underwent repair at 25.0 [23.3-26.4] weeks. During the postoperative MRI at 31.2 [29.9-33.3] weeks, T2 hyperintensity was seen in 35/49 (71.4%) fetuses. ADC values were lower in most studied brain regions in fetuses with T2 hyperintensity compared with their counterparts without T2 hyperintensity (right parietal lobe: 2.68 [1.38-7.82] ×10-6 mm2/s versus 3.36 [2.32-7.05] ×10-6 mm2/s, P = .02; left parietal lobe: 2.80 [1.40-7.38] versus 3.45 [1.81-7.58] ×10-6 mm2/s, P = .03; right temporal lobe: 2.75 [1.41-6.63] versus 3.53 [1.87-7.58] ×10-6 mm2/s, P <.01; right occipital lobe: 3.19 [1.20-7.86] versus 4.30 [2.18-7.18], P = .04). Complete hindbrain herniation reversal was more common in those without T2 hyperintensity (100% versus 65.7%, P < .01).
CONCLUSIONS: After prenatal ONTD repair, the presence of T2 hyperintensity was associated with lower ADC values in most examined brain regions, suggesting altered brain microstructure or delayed myelination.
引用
- Corroenne R, Sanz Cortes M, Whitehead WE, et al. T2 Hyperintensity and ADC Values in Fetal Brain MRI following Prenatal Open Neural Tube Defect Repair. AJNR Am J Neuroradiol. 2026. PMID: 42082315. doi:10.3174/ajnr.A9099
供执业医师工作参考，不替代临床判断；数值与分级以指南原文为准。