How to perform a fetal neurosonography: Key points

Congenital anomalies of the Central Nervous System are one of the most important and numerous groups of congenital malformations. They constitute the second cause of disability in childhood and more than 95% occur in a population without known risk. The most effective strategy for its detection is to differentiate between 2 levels of care. The first level, the BASIC ULTRASONOGRAPHY, is performed on all pregnant women, while the second level, the DETAILED FETAL NEUROSONOGRAPHY, is performed in cases selected due to the risk of anomaly based on a list of indications or because an abnormality has been detected or suspected. CNS abnormality on basic ultrasound. Its purpose is to perform a complete morphological and biometric multiplanar analysis of all accessible and recognizable brain structures from the axial, coronal and sagittal planes, ideally through transabdominal and transvaginal access. In the 3 plans, an attempt should be made to evaluate the same structures, assuming the limitations posed by the different perspective provided by each of them. When performing it, it is essential to take into account the indication and gestational age, know the morphological patterns, have reference tables of the normality of the different intracranial structures for GD and follow the systematics proposed by scientific societies. The objective of this article is to describe the different planes and provide readers with the key points for the ultrasound detection of the most important and frequent malformations of the CNS.