Volumetric Magnetic Resonance Imaging (MRI) at Term Predicts Motor Development at 2 years in Preterm Infants with Post-Hemorrhagic Ventricular Dilatation

Abstract

Background: Premature infants with Post-Hemorrhagic Ventricular Dilatation (PHVD) have a high risk of disabilities but prediction of grade of motor and mental outcome is difficult using ultrasound.Aims: To investigate the correlation of both qualitative and volumetric MRI at term with neurodevelopmental outcome at 2 years.Methods: 36 premature infants with PHVD, had cerebral MRI at term. MR images were assessedt by two observers unaware of treatment or outcome. Brain regions were assessed and abnormalities scored. In a subgroup of 25 infants, total and regional cerebral volumes were calculated using a manual segmentation technique. Bayley Scales of Infant Development were examined at 2 years past term. As many infants scored below 50 on the Bayley scales, Developmental Quotients (DQ) were calculated from Developmental Age Equivalent scores to provide continuous variables for all.Results: Qualitative analysis correlated weakly with motor and mental DQ. Total brain volume, excluding ventricles, showed strong positive linear correlation with motor, but not mental DQ (p 0.001). Figure [MR vol v DQ] Brain volume < 296 ml had 100% positive predictive value for DQ < 55. Thalamic volume and cerebellar volume correlated strongly with motor but not mental DQ. 29.5% of infants showed normal posterior limb of internal capsule (PLIC) but had mean motor DQ 67.Discussion: Volumetric brain measurements provided a better prediction of motor development than did qualitative assessment.