The feasibility of a common stereotactic space for children and adults in fMRI studies of development

The question of whether pediatric and adult neuroimaging data can be analyzed in a common stereotactic space is a critical issue for developmental neuroscience. Two studies were performed to address this question. In Study 1, high-resolution structural MR brain images of 20 children (7-8 years of age) and 20 young adults (18-30 years of age) were transformed to a common space. Overall brain shape was assessed by tracing the outer boundaries of the brains in three orientations, and more local anatomy was assessed by analysis of portions of 10 selected sulci. Small, but consistent, differences in location and variability were observed in specific locations of the sulcal tracings and outer-boundary sections. In Study 2, a computer simulation was used to assess the extent to which the small anatomical differences observed in Study 1 would produce spurious effects in functional imaging data. Results indicate that, assuming a functional resolution of 5 mm in images averaged across subjects, anatomical differences in either variability or location between children and adults of the magnitude obperved in Study 1 would not negatively affect functional image comparisons. We conclude that atlas-transformed brain morphology is relatively consistent between 7- and 8-year-old children and adults at a resolution appropriate to current functional imaging and that the small anatomical differences present do not limit the usefulness of comparing child and adult functional images within a common stereotactic space.