Pediatric neurosonography.

Neurosonography is an excellent modality for imaging a wide array of intracranial pathology in the infant and newborn. Neurosonography is also finding increasing use in other accessible regions of the central nervous system, including the adult brain during craniotomy and the spine during laminectomy. Sonography represents the primary modality for the evaluation of the preterm brain. Because of the high incidence of pathology in gestationally immature neonates, screening sonography is required in every infant. The sonographic features of intracranial hemorrhage include areas of increased echogenicity in the region of the germinal matrix, within the ventricles, or in the surrounding cerebral parenchyma. Careful follow-up of these children for sometimes severe posthemorrhagic hydrocephalus is essential. Premature neonates are also at risk for ischemic disease, particularly periventricular leukomalacia, which is accurately diagnosed sonographically and implies a poor prognosis in almost every infant so affected. Cranial sonography is also an excellent method to evaluate abnormalities that are not associated with gestational immaturity. Cranial sonography offers excellent anatomic imaging of the brain when evaluating for congenital anomalies; because sections may be obtained in a multitude of orientations, sonography is actually more versatile than computed tomographic (CT) scans. Cranial sonography is also of use when evaluating children with inflammatory processes such as ventriculitis; sonography is superior to CT scans in identifying intraventricular septae typical of the process. Intrauterine inflammatory processes, however, are frequently associated with intracranial calcifications, CT scans may be more accurate in these cases. CT scans may also be more efficacious in the diagnosis of subdural, epidural, and subarachnoid hemorrhage. Intracranial neoplasms are rare in the younger population and although they are visible with ultrasound, CT scans with contrast are essential in an effort to obtain added information and because of a greater experience using CT scans. Sonography represents an excellent modality with which to evaluate the infant and neonatal brain. In a number of diseases it may be diagnostic alone. The informed clinician, however, should keep in mind those instances where a complimentary modality such as CT scanning can add additional or even essential information.