Biometric magnetic resonance imaging analysis of fetal brain development in down syndrome

ObjectivesTo assess brain development in living fetuses with Down syndrome (DS) by biometric measurements on fetal brain magnetic resonance images (MRI).MethodsWe scanned 10 MRIs of fetuses with confirmed trisomy 21 at birth and 12 control fetal MRIs without any detected anomalies. Fetal brain MRIs were analyzed using 14 fetal brain and skull biometric parameters. We compared measures between DS and controls in both raw MRIs and motion-corrected and anterior-posterior commissure-aligned images.ResultsIn the reconstructed images, the measured values of the height of the cerebellar vermis (HV) and anteroposterior diameter of the cerebellar vermis (APDV) were significantly smaller, and the anteroposterior diameter of the fourth ventricle (APDF) was significantly larger in fetuses with DS than controls. In the raw MRIs, the measured values of the right lateral ventricle were significantly larger in fetuses with DS than in controls. Logistic regression analyses revealed that a new parameter, the cerebellar-to-fourth-ventricle ratio (i.e., (APDV * Height of the vermis)/APDF), was significantly smaller in fetuses with DS than controls and was the most predictive to distinguish between fetuses with DS and controls.ConclusionsThe study revealed that fetuses with DS have smaller cerebellums and larger fourth ventricles compared to the controls. What is already known about this topic?The understanding of the anatomical brain abnormalities in Down syndrome (DS) has come mostly from fetal autopsies, demonstrated by a grossly reduced brain weight.Knowledge from living fetuses with DS is scarce and comes mainly from sonographic analyses.Biometric MRI measurement is gaining widespread acceptance to evaluate fetal brain development.What does this study add?Our biometric measures revealed that fetuses with DS have smaller cerebellums and larger fourth ventricles compared with controls.Smaller cerebellar-to-fourth-ventricle ratios may be a novel fetal brain feature that is characteristic of DS.

Automated summary

This study aims to evaluate brain development in living fetuses with Down syndrome (DS) by analyzing biometric measurements on fetal brain magnetic resonance images (MRI). The results show that fetuses with DS have smaller cerebellums and larger fourth ventricles compared to controls, and the cerebellar-to-fourth-ventricle ratio may be a novel fetal brain feature characteristic of DS.