Lucile Bompard, Abstract Co-Author: Nothing to Disclose

Sarael Alcauter, Abstract Co-Author: Nothing to Disclose

Wei Gao, Abstract Co-Author: Nothing to Disclose

Weili Lin PhD, Presenter: Nothing to Disclose

One of the common features reported in the adult resting fMRI studies is the presence of strong functional connectivity between the homologous regions of the two hemispheres. To this end, we postulate that the presence of homologous connectivity may reflect maturation of brain functional networks. To test this hypothesis, the growth trajectory of functional connectivity strengths between homologous regions of the brain from birth to two years was evaluated.

65 (35 girls) healthy children underwent resting state fMRI scan using a 3T MR scanner (Siemens Medical systems) starting from birth, followed by every three months during the first and every 6 months during the second year. After wrapping images onto the Montreal Neurological Institute (MNI) space, the left-right correspondence was established based on non-linear registration. Bilateral symmetric functional connectivity between pairs of homologous voxels was evaluated. The voxel-wise growth trend was modeled using a linear mixed effect model with correlation coefficients as the dependent variable. Regional growth trajectories were determined based on Automatic Anatomical Labeling (AAL) atlas masking.

With the exception of the superior and inferior medial frontal and medial occipital areas, most of brain regions show a low symmetrical functional connectivity at birth, suggesting an immature brain. In addition, there appears an inverse relation between the connectivity strengths at birth and the growth rate of symmetric connectivity with age. That is, regions with a low functional connectivity at birth (bottom 25th percentile) are typically associated with a high slope and vice versa. Brain regions met the former condition include 6 regions in the parietal and temporal lobes, respectively. In contrast, regions met the latter condition include 5 in frontal, 4 in subcortical, 3 in limbic, 2 in occipital and 1 in parietal regions, respectively.

Our results suggest that highly connected homologous regions at birth are typically associated with a low slope and vice versa.

Assessments of functional connectivity between homologous brain regions may shed light on the status of brain functional maturation.

Bompard, L, Alcauter, S, Gao, W, Lin, W, Connectivity Strength between Homologous Brain Regions May Reflect Brain Functional Maturation during the First Two Years of Life.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14013483.html