Practice parameter: neuroimaging of the neonate: report of the Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society

Abstract

Objective: The authors reviewed available evidence on neonatal neuroimaging strategies for evaluating both very low birth weight preterm infants and encephalopathic term neonates.

Imaging for the preterm neonate: Routine screening cranial ultrasonography (US) should be performed on all infants of <30 weeks' gestation once between 7 and 14 days of age and should be optimally repeated between 36 and 40 weeks' postmenstrual age. This strategy detects lesions such as intraventricular hemorrhage, which influences clinical care, and those such as periventricular leukomalacia and low-pressure ventriculomegaly, which provide information about long-term neurodevelopmental outcome. There is insufficient evidence for routine MRI of all very low birth weight preterm infants with abnormal results of cranial US.

Imaging for the term infant: Noncontrast CT should be performed to detect hemorrhagic lesions in the encephalopathic term infant with a history of birth trauma, low hematocrit, or coagulopathy. If CT findings are inconclusive, MRI should be performed between days 2 and 8 to assess the location and extent of injury. The pattern of injury identified with conventional MRI may provide diagnostic and prognostic information for term infants with evidence of encephalopathy. In particular, basal ganglia and thalamic lesions detected by conventional MRI are associated with poor neurodevelopmental outcome. Diffusion-weighted imaging may allow earlier detection of these cerebral injuries.

Recommendations: US plays an established role in the management of preterm neonates of <30 weeks' gestation. US also provides valuable prognostic information when the infant reaches 40 weeks' postmenstrual age. For encephalopathic term infants, early CT should be used to exclude hemorrhage; MRI should be performed later in the first postnatal week to establish the pattern of injury and predict neurologic outcome.