An Association Between Fetal Subarachnoid Space and Various Pathologies Using MR Imaging

Area of Science:

• Neuroimaging
• Fetal Medicine
• Radiology

Background:

• Fetal brain development is complex and susceptible to various pathologies.
• Accurate assessment of fetal brain structures is crucial for early diagnosis and management.
• The fetal subarachnoid space (SAS) is a key anatomical feature whose width may correlate with brain development and pathology.

Purpose of the Study:

• To investigate the relationship between fetal subarachnoid space (SAS) width and specific fetal pathologies.
• To determine if SAS measurements can serve as a biomarker for conditions such as microcephaly, macrocephaly, and fetal growth restriction (FGR).

Main Methods:

• Retrospective analysis of fetal brain MRI scans from 78 fetuses with indications of microcephaly, macrocephaly, or FGR.
• Manual measurement of SAS width (SAS index) in ten anatomical locations (axial and coronal planes).
• Comparison of SAS index centiles against data from apparently healthy fetuses, with statistical analysis using Kruskal-Wallis and Mann-Whitney U tests.

Main Results:

• Median SAS centiles were significantly higher in the macrocephaly group compared to the microcephaly group.
• Median SAS centiles were higher in the microcephaly group compared to the FGR group across most locations.
• Statistically significant differences in SAS width were observed between the studied groups, particularly in the insula and frontal gyri.

Conclusions:

• A significant association exists between fetal subarachnoid space width and fetal pathologies including macrocephaly, microcephaly, and FGR.
• SAS measurements derived from fetal MRI show potential as a diagnostic indicator for these conditions.
• Further research can explore the clinical utility of SAS index in prenatal diagnosis and management.