Sonography of the brain in infants: role in evaluating neurologic abnormalities

Three primary imaging techniques are currently available for evaluating CNS disease in the infant: sonography, CT, and MR imaging. No one technique is optimal in all situations. An integrated approach may be the most appropriate and cost-effective. Sonography plays a role in screening for and following up intracranial hemorrhage in premature infants, in diagnosing congenital malformations of the brain, and in the initial diagnosis and follow-up of infants with hydrocephalus. Sonography can be used to diagnose periventricular leukomalacia and hypoxic/ischemic injury, but it is relatively insensitive in the acute phase. Doppler sonography plays a role in determining if a structure is vascular, such as vein of Galen aneurysm, and in assessing embolization of a vascular malformation. Doppler sonography also can be used at the bedside to diagnose suspected thrombosis of intracranial vessels. The purpose of this essay is to review the role of sonography in the diagnosis, treatment, and follow-up of these conditions.