MRI for early prediction of outcome in preterm infants: Which items?

Abstract

Objectives Early prediction of neurologic outcome of preterm infants is challenging. MRI provides interesting insights. Usual MRI interpretation looking for lesions (hemorrhage, cystic lesions, infarction, or “qualitative abnormalities”) has good predictive value for severe motor disabilities. Conversely those standard items are poor predictors of later, cognitive impairments. For this purpose, measuring volume of brain structures and cerebral growth is promising. In a prospective cohort study, we assessed global and regional cerebral growth, compared to outcome. Methods Infants born before 30 gestation weeks underwent serial MRI (between 25 and 28 weeks of gestation, then every three weeks until term). Cerebrum, cerebellum, brainstem, fluid spaces were estimated through twenty-five 2D measurements. Outcome was assessed with Bayley scale at two years of age. Results Hundred and eight preterm infants were included and 266 MRI performed. Main qualitative abnormalities were low-grade IVH (22%), severe IVH (6%), severe white matter injuries (21%), Cerebellar injuries (19%). Brain/Bone biparietal diameter, which has previously been strongly correlated with global cerebral volume, was significantly lower, as cerebellum and brainstem measurements. Impairment of regional brain growth is correlated with 2 years outcome. Conclusion We need to further search for correlation with later outcome at five and eight years. Brain MRI is a promising tool for early prognosis, but standard interpretation might include volume and cerebral growth assessments.