Background and Aim: In recent years, advances in imaging techniques have allowed investigating neurodevelopmental processes in newborns. As emerging tools, structural and functional connectivity analyses are becoming inevitable to study the brain's structure and functions at large-scale network level. A combined functional and structural connectivity analysis provides a better picture to fully explore the undelaying mechanisms of brain functions in newborns. Methods: In this work, we used the diffusion-weighted images (DWI) and ۱۵-min resting-state functional magnetic resonance image (rsfMRI) data from ۴۰ term neonates (aged ۳۷-۴۴ weeks GA) included in the developing human connectome project (http://www.developingconnectome.org/). The rsfMRI data (TR=۳۹۲ms) were first pre-processed using the most standard preprocessing steps including slice-timing, realignment, motion correction, registration to the neonatal template, spatial smoothing and temporal filtering (۰.۰۰۹- ۰.۰۸ Hz). The DW images (b۰ s/mm۲ and b۱۰۰۰) were also preprocessed through motion correction, eddy current correction and susceptibility field distortion correction using the FSL toolbox. The deterministic streamline tractography (Euler Tracking algorithm) was used to perform fiber tracking using the DSI-studio software (http://dsi-studio.labsolver.org/). The AAL atlas including ۹۹ parcels was then used to calculate functional (FC) and structural connectivity (SC) matrices for each neonate. The group average FC matrix was binarized using a network density of ۲۰% found based on the maximum global efficiency of the network. A backbone SC was also computed by preserving structural connections across at least ۹۰% of the neonates. We finally performed the functional and structural connectivity analysis using the Brain Connectivity Toolbox to identify rich-club nodes using ۱۰۰۰ random networks. The structural and functional rich-club (RC) organizations were then compared to identify regions with a normalized RC coefficient greater than ۱ with p<۰.۰۵. Results: In this study, the intersection between the structural and resting-state functional rich- club organizations of the brain networks was investigated in full-term newborns. Conclusion: The structural rich club map comprised only ۲۳% of the network nodes mostly localized in the bilateral frontal, temporal, parietal and central regions and cerebellum. The functional rich club map also included ۲۲% of the network nodes restricted to the bilateral central, left prefrontal, right frontal and parietal regions. Our results showed only ۳۰% overlap between the structural and functional rich club maps, located in bilateral central and right frontal and parietal regions. Our results demonstrate that highly connected structural and functional brain hubs are mostly restricted to the right hemisphere in full-term neonates.
