Supratentorial parenchyma in the developing fetal brain: in vitro MR study with histologic comparison

Area of Science:

• Neuroimaging
• Developmental Neuroscience
• Histology

Background:

• Understanding fetal brain development is crucial for diagnosing congenital abnormalities.
• Magnetic resonance (MR) imaging offers non-invasive insights into brain structure.
• Histologic correlation is essential for validating MR findings.

Purpose of the Study:

• To evaluate the in vitro MR signal characteristics of the developing human fetal brain.
• To correlate MR imaging findings with detailed histologic examination.
• To establish cellular correspondence for observed MR signal patterns.

Main Methods:

• In vitro MR imaging (T1- and T2-weighted sequences) was performed on five healthy fetal specimens (16-34 weeks' gestation).
• Histopathologic analysis of brain sections was conducted in the same planes as MR imaging.
• Signal intensity layers on MR images were compared with histologic layers to determine cellular origins.

Main Results:

• A distinct layered pattern was observed in the cerebral mantle on both T1- and T2-weighted MR images.
• Signal characteristics in the basal ganglia (pallidum, thalamus, neostriatum) changed with gestational age.
• Specific signal alterations in the pallidum, thalamus, and neostriatum at later gestational ages (27-34 weeks) were identified.

Conclusions:

• In vitro MR imaging effectively visualizes specific developmental patterns in the fetal brain.
• The study provides a foundation for interpreting in vivo fetal brain MR imaging.
• MR signal changes reflect underlying cellular development and maturation in the fetal brain.