43 Total Cerebral Volume Measurements Following Preterm Birth

Abstract

Background. Preterm infants have reduced cerebral tissue volumes in adolescence, and relative loss of some brain regions in early childhood, but it is unclear if this is due to perinatal or more prolonged growth failure. We therefore compared total cerebral tissue volume in preterm infants at term equivalent age and term born controls. Methods. Subjects: We studied 89 preterm infants born at median 29.7 weeks GA without parenchymal lesions at median 40.57 weeks, and 20 term born controls (median 40.43 weeks GA). Image acquisition: A 1.5 Tesla MR system was used to acquire T1-weighted volume datasets with a voxel size 1x1x1.6mm, in addition to conventional and diffusion weighted imaging. Image processing: A non-rigid image registration algorithm transformed all images to a reference subject, and transformations were used to propagate region of interest (ROI) labels segmented in the reference anatomy to the corresponding structure in all subjects. The volume change for each ROI relative to the reference was computed, enabling cerebral tissue volume measurements (excluding CSF) to be calculated for each subject. Results. Mean cerebral tissue volume in preterm infants at term was 404.9cm3; and in term controls, 401.1cm3 (p=0.765). Diffuse white matter injury, oxygen requirement at 28 days, and intrauterine growth restriction were not associated with significant reductions in cerebral tissue volume. Conclusions. Despite evidence of regional and later growth failure, total brain tissue volume in preterm infants at term is similar to term born controls.