Attention-Deficit/ Hyperactivity Disorder Brain Functional Reference: Introducing an Inter-subject Consistency Measure and Dual-layer Parcellation

Abstract

The latest advancements in neuroimaging techniques have contributedto studying the disordered human brain, but still, there is a lack ofdisease-specific brain reference to localise brain seeds and standardisethe comparison across studies. The current study first evaluates theinter-subject consistency across Attention-Deficit/ HyperactivityDisorder (ADHD) in a publicly accessible resting-state functionalmagnetic resonance imaging (RS-fMRI) ADHD-200 dataset by proposing a new voxels similarity index (VSI) that integrates bothinter-atlases flexibility (F`) from previous studies with proposed intersubjectsstability (S`) measure to improve outcomes. Secondly, thestudy employs a dual-layer clustering-based parcellation strategyinspired by the resultant improved Master Atlas networks to examinethe ADHD cerebral cortex. The suggested approach to enhancingthe ADHD cortex parcellation uses spectral clustering for globalstructure identification, followed by hierarchical clustering for localrefinements and granularity specification. The final connectivitydrivenbrain reference achieved an average homogeneity of 0.63,and the enhanced Master Atlas with (S’) achieved 0.35 homogeneity,surpassing the original Master Atlas with 0.27. This discovery impliesthat the final brain reference offers a more accurate and reliableframework to examine the connections and functions of the brain inindividuals with ADHD.