Objective Magnetic Resonance Imaging (MRI) has defined neurologic abnormalities in infants with congenital heart disease (CHD) including pre-operative injury and delayed brain maturation. This study utilized qualitative scoring, cerebral biometry, and diffusion imaging to characterize pre-operative brain abnormalities in infants with CHD, including the identification of regions of greater vulnerability. Methods Sixty-seven infants with CHD had pre-operative MRI with analysis for brain injury by qualitative scoring and brain development by qualitative scoring, metrics and diffusion imaging. Results Qualitative abnormalities were common, with 42% of infants having pre-operative focal white matter lesions. Infants with CHD had smaller brain measures in the frontal lobe, parietal lobe, cerebellum and brainstem (p<.001); with the frontal lobe and brainstem displaying the greatest alterations (p<.001). Smaller brain size in the frontal and parietal lobes correlated with delayed white matter microstructure reflected by diffusion imaging. Conclusion Infants with CHD commonly display brain injury and delayed brain development. Regional alterations in brain size are present, with the frontal lobe and brainstem demonstrating the greatest alterations, which may reflect a combination of developmental vulnerability and regional differences in cerebral circulation.

Background Infants with CHD have delayed brain maturation and alterations in brain volume. Brain metrics is a simple measurement technique that can be used to evaluate brain growth. This study used brain metrics to test the hypothesis that alterations in brain size persist at three months of age and that infants with CHD have slower rates of brain growth than control infants. Methods Fifty-seven infants with CHD underwent serial brain magnetic resonance imaging (MRI). To evaluate brain growth across the first three months of life, brain metrics were undertaken on 19 tissue and fluid spaces on MRIs performed pre-operatively and at three months of age. Results Pre-operatively, infants with CHD have smaller frontal, parietal, cerebellar and brainstem measures (p<0.001). At three months of age, alterations persisted in all measures except the cerebellum. There was no difference between control and CHD infants in brain growth. However, the cerebellum trended towards greater growth in infants with CHD. Somatic growth was the primary factor that related to brain growth. Presence of focal white matter lesions pre- and post-operatively did not relate to alterations in brain size or growth. Conclusion Although infants with CHD have persistent alterations in brain size at three months of age, rates of brain growth are similar to that of healthy term infants. Somatic growth was the primary predictor of brain growth, emphasizing the importance of optimal weight gain in this population.

No abstract