Cerebral cortex three-dimensional profiling in human fetuses by magnetic resonance imaging

Area of Science:

• Neuroscience
• Developmental Biology
• Medical Imaging

Background:

• Fetal brain development involves complex morphogenesis between the 12th and 16th weeks of gestation.
• Understanding in situ brain morphology during this period is crucial for tracking developmental dynamics.
• Previous methods lacked the resolution to detail internal structures and quantitative parameters.

Purpose of the Study:

• To evaluate in situ human fetal brain morphology using 3D MRI.
• To describe the developmental dynamics of the fetal brain during a key period of morphogenesis.
• To demonstrate the utility of high-resolution MRI for quantitative analysis of early brain development.

Main Methods:

• Three-dimensional reconstruction of seven human fetal brains (12-16 weeks gestation) via magnetic resonance imaging (MRI).
• Acquisition using a 4.7-T magnet with high spatial resolution (20 G cm(-1) gradient power).
• Optimization of contrast using T1 and T2 weighted sequences for visualization of layers, subplate, and marginal zones.

Main Results:

• 3D MRI demonstrated increasing brain maturation, with quantifiable changes in fronto-occipital distance, bitemporal distance, and occipital angle.
• High-spatial-resolution MRI allowed detailed detection of five cortical layers and visualization of the subplate and marginal zones.
• Cortical thickness mapping revealed a gradient from the insular cortex to the hemispheric periphery.

Conclusions:

• MRI is a valuable tool for studying human fetal brain development in situ.
• The methodology provides quantitative morphological parameters and insights into transient developmental features.
• This approach enables detailed profiling of brain maturation during early gestation.