Multi-echo ICA improves the sensitivity of BOLD fMRI blood flow delay estimates in subacute stroke

Motivation: Relative BOLD delays can non-invasively assess stroke-related cerebral blood flow changes. However, head motion affects data quality and limits clinical translation. Goal(s): Evaluate whether multi-echo ICA (ME-ICA), a technique for mitigating motion effects, makes BOLD delays more sensitive to subacute stroke. Approach: 13 participants with first-time subacute stroke, with and without clinical deficits, underwent fMRI scans. Delay laterality to lesions relative to contralesional control regions was calculated using data with ME-ICA or standard denoising. Results: ME-ICA did not affect laterality in the group without deficits but made delays significantly more lateralized to the lesion area in the group with deficits. Impact: ME-ICA increases the sensitivity of BOLD delay estimates to changes in cerebral blood flow for moderately severe sub-acute stroke participants. Ultimately, this work will allow for noninvasive assessment of cerebral blood flow changes with reduced participant attrition due to motion.