Limitations of routine neuroimaging in predicting outcomes of preterm infants.

INTRODUCTION

Preterm births are increasing in number and while the rates of cerebral palsy have declined, there are increasing numbers of infants who survive with handicaps. In some studies, up to 50 % of children will have morbidity when followed up to school age.

METHODS

A review of current literature was conducted to determine the validity of routine cranial ultrasound scans (CUS) to predict neurodevelopmental outcomes, including motor and cognitive deficits. We also reviewed the additional benefit offered by including MRI scans in scanning protocols to enhance the reliability in predicting the neurodevelopmental sequelae of prematurity.

RESULTS

CUS is valuable as a screening tool to determine significant brain injury when conducted regularly over the first weeks of life in preterm infants. Subtle changes on CUS are difficult to interpret and more precise information is offered by performing MRI scans. These are most often carried out at term equivalent age but earlier scans may be just as useful in predicting neurocognitive outcomes. When MRI scans are either normal or seriously abnormal, there is a very clear correlation with outcome to 2 years of age. Mild and moderate degrees of injury defined on MRI need more sophisticated scanning sequences to determine the likelihood of associated sequelae. Follow-up to school age is essential to diagnose more subtle cognitive delays.

CONCLUSION

CUS provides a good screening tool to detect serious brain injury resulting in motor handicaps but MRI scans are complementary and necessary to accurately predict the outcomes of preterm infants, especially cognitive delays.