Objective: To compare regional brain volumes measured in term and preterm infants, and to correlate regional volumes with measures of neurodevelopmental outcome.
Methods: High-contrast, high-resolution magnetic resonance imaging scans were acquired in 10 preterm and 14 term infants who were scanned near term. The cerebrum was segmented into cortical gray matter, white matter, cerebral ventricles, subcortical gray matter, cerebellum, and brainstem. The cortical gray matter, white matter, and ventricles were further divided into specific anatomic subregions, and the volumes were compared across groups. Measures of cognitive and motor development were acquired between 18 and 20 months of corrected age. Correlations of regional brain volumes with developmental outcome were assessed in the preterm group.
Results: Volumes in preterm infants were reduced in parieto-occipital gray matter and increased in the midbody, occipital horn, and temporal horns of the lateral ventricles. Gray matter volumes were also less prominently reduced in the sensorimotor and inferior occipital cortices. Normal lateralization of white matter volumes were altered in the parieto-occipital region in the preterm infants, who had significantly larger left-sided and smaller right-sided structures. White matter volumes in the sensorimotor and midtemporal regions correlated strongly with measures of neurodevelopmental outcome.
Conclusions: These findings of reduced volumes in sensorimotor and parieto-occipital regions in preterm infants, and the prospective correlations of regional volumes with cognitive outcome, confirm and extend findings previously reported in a cross-sectional study of 8-year-old prematurely born children. The data suggest that regional brain volumes near term are a promising marker for predicting disturbances of cognitive outcome in preterm infants. Further prospective, longitudinal studies of neonatal brain volumes and developmental indices into later childhood are required to confirm the utility of regional brain volumes as predictors of longer term outcome.