Comparison of cranial ultrasound and MRI for detecting BRAIN injury in extremely preterm infants and correlation with neurological outcomes at 1 and 3 years

This study aimed to investigate the accuracy of different grades of brain injuries on serial and term equivalent age (TEA)-cranial ultrasound imaging (cUS) as compared to TEA magnetic resonance imaging (MRI) in extremely preterm infants <28weeks, and determine the predictive value of imaging abnormalities on neurodevelopmental outcome at 1 and 3years. Seventy-five infants were included in the study. Severe TEA-cUS injury had high positive predictive value-PPV (100%) for predicting severe MRI injury compared to mild to moderate TEA-cUS injury or severe injury on worst cranial ultrasound scan. Absence of moderate to severe injury on TEA cUS or worst serial cUS was a good predictor of a normal MRI (negative predictive values >93%). Severe grade 3 injuries on TEA-US had high predictive values in predicting abnormal neurodevelopment at both 1 and 3years of age (PPV 100%). All grades of MRI and worst serial cUS injuries poorly predicted abnormal neurodevelopment at 1 and 3years. Absence of an injury either on a cranial ultrasound or an MRI did not predict a normal outcome. Multiple logistic regression did not show a significant correlation between imaging injury and neurodevelopmental outcomes.Conclusion: This study demonstrates that TEA cUS can reliably identify severe brain abnormalities that would be seen on MRI imaging and positively predict abnormal neurodevelopment at both 1 and 3years. Although MRI can pick up more subtle abnormalities that may be missed on cUS, their predictive value on neurodevelopmental impairment is poor. Normal cUS and MRI scan may not exclude abnormal neurodevelopment. Routine TEA-MRI scan provides limited benefit in predicting abnormal neurodevelopment in extremely preterm infants.