Division of Neuroradiology and Musculoskeletal Radiology, Department of Biomedical Imaging and Image-guided Therapy, Allgemeines Krankenhaus, Medical University of Vienna, Vienna, Austria.
Department of Biology, School of Medicine, University of Zagreb, Zagreb, Croatia.
Acta Obstet Gynecol Scand. 2024 May;103(5):897-906. doi: 10.1111/aogs.14781. Epub 2024 Feb 9.
This study aimed to assess the visibility of the indusium griseum (IG) in magnetic resonance (MR) scans of the human fetal brain and to evaluate its reliability as an imaging biomarker of the normality of brain midline development.
The retrospective observational study encompassed T2-w 3T MR images from 90 post-mortem fetal brains and immunohistochemical sections from 41 fetal brains (16-40 gestational weeks) without cerebral pathology. Three raters independently inspected and evaluated the visibility of IG in post-mortem and in vivo MR scans. Weighted kappa statistics and regression analysis were used to determine inter- and intra-rater agreement and the type and strength of the association of IG visibility with gestational age.
The visibility of the IG was the highest between the 25 and 30 gestational week period, with a very good inter-rater variability (kappa 0.623-0.709) and excellent intra-rater variability (kappa 0.81-0.93). The immunochemical analysis of the histoarchitecture of IG discloses the expression of highly hydrated extracellular molecules in IG as the substrate of higher signal intensity and best visibility of IG during the mid-fetal period.
The knowledge of developmental brain histology and fetal age allows us to predict the IG-visibility in magnetic resonance imaging (MRI) and use it as a biomarker to evaluate the morphogenesis of the brain midline. As a biomarker, IG is significant for post-mortem pathological examination by MRI. Therefore, in the clinical in vivo imaging examination, IG should be anticipated when an assessment of the brain midline structures is needed in mid-gestation, including corpus callosum thickness measurements.
本研究旨在评估人脑胎儿磁共振（MR）扫描中灰结节（IG）的可见性，并评估其作为脑中线发育正常的影像学生物标志物的可靠性。
这项回顾性观察性研究纳入了 90 例尸检胎儿脑 T2-w 3T MR 图像和 41 例无脑部病变的胎儿脑（16-40 孕周）免疫组化切片。三位评估者分别独立检查和评估尸检和活体 MR 扫描中 IG 的可见性。使用加权 Kappa 统计和回归分析来确定 IG 可见性的组内和组间一致性以及与胎龄的关联类型和强度。
IG 的可见性在 25 至 30 孕周之间最高，具有非常好的组间可变性（kappa 0.623-0.709）和极好的组内可变性（kappa 0.81-0.93）。IG 组织学结构的免疫化学分析揭示了 IG 中高度水合的细胞外分子的表达，作为中胎儿期 IG 信号强度更高和可见性最佳的底物。
对发育中脑组织学和胎儿年龄的了解使我们能够预测磁共振成像（MRI）中 IG 的可见性，并将其用作评估脑中线形态发生的生物标志物。作为一种生物标志物，IG 对于 MRI 后进行尸检病理学检查具有重要意义。因此，在临床活体成像检查中，当需要评估中孕期脑中线结构时，包括胼胝体厚度测量，应预期到 IG 的存在。
