The Impact of Customized Head Molds on Motion and Motion-related Artifacts From Structural and Functional MRI Scans in Children

Each participant completed a dedicated session for mock scanning before we acquired two sets of sMRI and fMRI scans. One scan set was collected using the head mold and the other without, and the scans were counterbalanced in order across participants. Using a specialized sMRI sequence embedded with vNAVs, we directly measured head motion during sMRI in order to more accurately evaluate the head mold's impact on structural metrics. To evaluate the feasibility and tolerability of the head mold, we concluded the scanning sessions with a brief interview that gauged participants' scanning experience and tolerance of the head mold. We investigated whether head molds would reduce head motion compared to standard scanning procedures and whether those reductions would result in improved data quality. We also tested the extent to which reductions in head motion impacted estimations of cortical volume and functional connectivity. Prior to data collection, we evaluated the noise dosage levels of the head mold condition, given the limited space available for additional hearing protection devices in the head coil while the head mold is on. We also assessed whether the head molds could balance head motion between typical and ADHD populations, and whether clinical variables such as ADHD diagnosis and trait anxiety, as determined by parent-reported dimensional measures, can predict head mold efficacy.