ABSTRACT
Sonographic assessment of the fetal brain in the sagittal and coronal sections requires an approach through anterior/posterior fontanelle and/or the sagittal suture. Transvaginal sonography of the fetal brain opened a new field in medicine, “neurosonography”. “Hydrocephalus” and “ventriculomegaly” are both the terms used to describe dilatation of the lateral ventricles. The term of “hydrocephalus” does not identify a specified disease, but is a generic term that means a group of pathologic conditions due to abnormal circulation of cerebrospinal fluid (CSF). The term of “hydrocephalus” does not identify a specified disease, but is a generic term that means a group of pathologic conditions due to abnormal circulation of CSF. Congenital hydrocephalus is classified into three categories by causes that disturb CSF circulation pathway: simple hydrocephalus, dysgenetic hydrocephalus, and secondary hydrocephalus. Encephalocele occurs in the occipital region in 70% to 80%.
