Additional Value of 3-Month Cranial Magnetic Resonance Imaging in Infants with Neonatal Encephalopathy following Perinatal Asphyxia

Abstract

To assess the evolution of neonatal brain injury noted on magnetic resonance imaging (MRI), develop a score to assess brain injury on 3-month MRI, and determine the association of 3-month MRI with neurodevelopmental outcome in neonatal encephalopathy (NE) following perinatal asphyxia. Retrospective single-center study including 63 infants with perinatal asphyxia and NE (n=28 cooled) with cranial MRI <2 weeks and 2-4 months after birth. Both scans were assessed using biometrics, a validated injury score for neonatal MRI, and a new score for 3-month MRI, with a white matter (WM), deep gray matter (DGM), and cerebellum sub-score. The evolution of brain lesions was assessed, and both scans were related to 18-24 month composite outcome. Adverse outcomes included cerebral palsy, neurodevelopmental delay, hearing/visual impairment, and epilepsy. Neonatal DGM injury generally evolved into DGM atrophy and focal signal abnormalities, and WM/watershed injury evolved into WM and/or cortical atrophy. While the neonatal total and DGM scores were associated with composite adverse outcomes, the 3-month DGM score (OR 1.5, 95% CI 1.2 - 2.0) and WM score (OR 1.1, 95% CI 1.0 - 1.3) were also associated with composite adverse outcomes (occurring in n=23). The 3-month multivariable model (including the DGM and WM sub-scores) had higher positive (0.88 versus 0.83) but lower negative predictive value (0.83 versus 0.84) than neonatal MRI. Inter-rater agreement for the total, WM, and DGM 3-month score was 0.93, 0.86, and 0.59. Especially DGM abnormalities on 3-month MRI, preceded by DGM abnormalities on the neonatal MRI, were associated with 18-24 month outcome, indicating utility of 3-month MRI for treatment evaluation in neuroprotective trials. However, the clinical usefulness of 3-month MRI seems limited compared with neonatal MRI.