Repeatability and reliability of cerebrovascular reactivity in young adults using multi-echo, multi-contrast MRI

Motivation: Cerebrovascular reactivity (CVR) shows promise as an imaging biomarker of early changes in vascular integrity but is challenging to acquire in non-compliant patient populations. Microvascular-weighted images may be more specific to disease-related pathology, but these acquisitions suffer from lower contrast-to-noise ratio. Goal(s): We aim to evaluate the repeatability and reliability of CVR mapping using a combined spin- and gradient-echo (SAGE) acquisition across three CVR paradigms requiring varying levels of compliance. Approach: SAGE-CVR data were collected. Repeatability and reliability metrics were calculated for total and microvascular-weighted SAGE-CVR, with comparison to single-echo CVR. Results: Repeatability and reliability significantly improved with SAGE-CVR compared to single-echo CVR. Impact: SAGE-fMRI improves repeatability and reliability of CVR, increasing feasibility of CVR evaluation in patient populations. SAGE-fMRI offers complementary CVR assessments on total and microvascular scales, where a robust microvascular-weighted analysis may be relevant to the study of many neurovascular diseases.