Normal sulcation and gyration in neonatal cranial sonography from 24 weeks gestational age until term: a pictorial essay.

Cranial ultrasound remains the most practical and available imaging modality for evaluating the brain of neonates. This is a pictorial essay on preterm (≥24 weeks) and term neonates who had an unremarkable cranial ultrasound in the first week of life at St. Luke's Medical Center Quezon City and St. Luke's Medical Center Global City from January 2017 to December 2021. We present two images for each landmark week of gestation in this retrospective multicentric review. The first image is in the coronal plane depicting the foramen of Monro and the third ventricle and the second image is in the sagittal plane at the level of the caudothalamic groove. The goal is to create an easy-to-use reference for the typical appearance and progression of the normal sulcation and gyration of the neonatal brain on ultrasound, depending on the weekly gestational age. Having a reference atlas matched for gestational age is a helpful tool for screening a myriad of pathologies and is expected to help clinicians and radiologists involved in the care of neonates monitor the development of the brain.