Neurosonographic features of central nervous system infections in infancy and childhood.

Infections of the central nervous system (CNS) are a serious threat to the developing brain and are a major cause of neurologic handicap in the young. Of the neuroimaging modalities available, cranial ultrasonography has become an important technique in providing information about intracranial infection because of its portability, low cost, minimal morbidity, and diagnostic image quality. Authors of recent reports described ultrasonographic changes in brain parenchyma, extracerebral fluid, and ventricles. Parenchymal changes have been observed with cerebritis, edema, hemorrhage, infarction, and abscess formation; changes in extracerebral fluid include effusion and empyema; and ventricular changes associated with ventriculitis and hydrocephalus have been reliably described. By identifying changes associated with intracranial infections, ultrasonography has emerged as a technique that provides valuable information in making the diagnosis, identifying complications, and directing decisions in management of CNS infection.