Possibilities of magnetic resonance imaging for studying asymmetry of the lateral ventricles of the brain in the fetus
The article presents a retrospective analysis of the results of MRI of the brain in 292 fetuses of both sexes, the gestational age – 19–38 wks. The width of the septum pellucidum, retrocerebellar and convexital parieto-occipital subarachnoid areas, and the lateral ventricles have been measured. It has been shown that asymmetry of non-enlarged lateral ventricles is more commonly associated with the presence of a CNS pathology, most often, with hemorrhagic changes. If the cause of asymmetry can not been found, the latter might be considered a variant of normal anatomic development. Asymmetry of enlarged lateral ventricles is almost equally characteristic for isolated and associated ventriculomegaly, if the severity of the latter increases, asymmetry is observed in more than half of the cases (54%). In asymmetric ventriculomegaly, the most often associated anomalies of the CNS were combined pathology (30%), hemorrhages, severe malformations, and Chiari malformation (22% each). In a considerably lesser degree asymmetry of the lateral ventricles is characteristic for pathologies of the posterior cranial fossa and the midline structures. A considerable prevalence of asymmetric ventricles over symmetric ones (4:1) occurs only in combined pathologies, in severe malformations this prevalence is less marked (2:1), and isolated hemorrhagic changes are characterized by an inverse ratio with the prevalence of symmetric ventricles (1:2).