Neuroimaging in the evaluation of neonatal encephalopathy

Computed tomography (CT) is still used for neuroimaging of infants with known or suspected neurologic disorders. Alternative neuroimaging options that do not expose the immature brain to radiation include MRI and cranial ultrasound. We aim to characterize and compare the use and findings of neuroimaging modalities, especially CT, in infants with neonatal encephalopathy.

The Vermont Oxford Network Neonatal Encephalopathy Registry enrolled 4171 infants (≥36 weeks' gestation or treated with therapeutic hypothermia) between 2006 and 2010 who were diagnosed with encephalopathy in the first 3 days of life. Demographic, perinatal, and medical conditions were recorded, along with treatments, comorbidities, and outcomes. The modality, timing, and results of neuroimaging were also collected.

CT scans were performed on 933 of 4107 (22.7%) infants, and 100 of 921 (10.9%) of those received multiple CT scans. Compared with MRI, CT provided less detailed evaluation of cerebral injury in areas of prognostic significance, but was more sensitive than cranial ultrasound for hemorrhage and deep brain structural abnormalities.

CT is commonly used for neuroimaging in newborn infants with neonatal encephalopathy despite concerns over potential harm from radiation exposure. The diagnostic performance of CT is inferior to MRI in identifying neonatal brain injury. Our data suggest that using cranial ultrasound for screening, followed by MRI would be more appropriate than CT at any stage to evaluate infants with neonatal encephalopathy.