Time frame: 20 Minutes Pre-Intervention, 20 Minutes Post-Intervention (Total duration: 60 min); Up to Week 7
CBF is measured as Blood Oxygen Level Dependent (BOLD) signal on functional magnetic resonance imaging (fMRI). BOLD signal reflects changes in regional CBF that delineate regional activity. A positive BOLD signal marks an increase in regional blood flow, while a negative BOLD signal marks a decrease in regional blood flow. A positive percent change indicates that blood flow increased in the region of interest between scans, a negative percent change indicates blood flow decreased between scans.
Approximately 60 minutes of fMRI data are recorded in the left and right dorsolateral prefrontal cortical regions of interest at each transcranial photobiomodulation (t-PBM) treatment visit, including: approximately 20 minutes prior to t-PBM administration, approximately 20 minutes coinciding with t-PBM administration, and approximately 20 minutes following t-PBM administration.