RESUMEN
The relationship between structural changes of the cerebral cortex revealed by Magnetic Resonance Imaging (MRI) and gene expression in the human fetal brain has not been explored. In this study, we aimed to test the hypothesis that relative regional thickness (a measure of cortical evolving organization) of fetal cortical compartments (cortical plate [CP] and subplate [SP]) is associated with expression levels of genes with known cortical phenotype. Mean regional SP/CP thickness ratios across age measured on in utero MRI of 25 healthy fetuses (20-33 gestational weeks [GWs]) were correlated with publicly available regional gene expression levels (23-24 GW fetuses). Larger SP/CP thickness ratios (more pronounced cortical evolving organization) was found in perisylvian regions. Furthermore, we found a significant association between SP/CP thickness ratio and expression levels of the FLNA gene (mutated in periventricular heterotopia, congenital heart disease, and vascular malformations). Further work is needed to identify early MRI biomarkers of gene expression that lead to abnormal cortical development.
Asunto(s)
Encéfalo/crecimiento & desarrollo , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/embriología , Malformaciones del Desarrollo Cortical/diagnóstico por imagen , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/embriología , Adulto , Encéfalo/diagnóstico por imagen , Corteza Cerebral/anomalías , Femenino , Feto/diagnóstico por imagen , Feto/metabolismo , Filaminas/genética , Expresión Génica/genética , Expresión Génica/fisiología , Edad Gestacional , Cabeza , Humanos , Imagen por Resonancia Magnética , Red Nerviosa/metabolismo , Embarazo , ARN Mensajero/biosíntesis , ARN Mensajero/genética , TranscriptomaRESUMEN
OBJECTIVE: The objective of the study was to characterize total and regional volumetric brain growth in healthy fetuses during the second and third trimesters of pregnancy, using an automated method. STUDY DESIGN: We developed and validated an automated method to quantify global and regional in vivo brain volumes using fetal magnetic resonance imaging. We then computed the percentage of growth for each brain structure in a cohort of 64 healthy fetuses (25.4-36.6 weeks' gestational age). RESULTS: The cerebellum demonstrated the greatest maturation rate, with a 4-fold increase (384%) in volume between 25.4 and 36.6 weeks, and a relative growth rate of 12.87% per week. Both total brain and cerebral volumes increased by 230% and brain stem volume by 134% over the same gestational age period. Conversely, lateral ventricular volume decreased by 4.18% per week. CONCLUSION: The availability and ongoing validation of normative fetal brain growth trajectories will provide important tools for early detection of impaired fetal brain growth upon which to manage high-risk pregnancies.