US of the neonatal brain can be easily performed demonstrating normal structures of the brain and abnormalities including anatomic abnormalities such as hydrocephalus, structural anomalies, hemorrhage or parenchymal edema. Coronal and sagittal scan through the anterior fontanelle is the standard imaging technique and additional imaging through the posterior fontanelle or temporal window or mastoid fontanelle can be helpful in certain conditions. Doppler US also useful for demonstrating vascular structures and resistive index can be used for the detection of global ischemia or follow-up studies. Major clinical indications are detection of germinal matrix or intraventricular hemorrhages in the premature babies or primary hemorrhages in the term babies. Hypoxic ischemic encephalopathy including periventricular leukomalacia in the premature and global or parasagittal ischemia in the term babies can be detected. Primary or secondary ventricular dilatation can be easily detected and complications of the meningitis such as ventriculitis, infarction, cerebritis, abscess formation or venous sinus thrombosis can be diagnosed. Extra axial fluid collections such as subarachnoid fluid or subdural fluid can be differentiated with demonstration of the arachnoid membrane or using the color Doppler study of the surface of the brain.
The anatomy and the clinical usage of neonatal brain ultrasonography will be discussed.