Whole-brain BOLD responses to graded hypoxic challenges at 7 T, 9.4 T, and 15.2 T: Implications for ultrahigh-field functional and dynamic susceptibility contrast MRI.

ABSTRACT:

Purpose

Blood oxygen-level dependent (BOLD) functional MRI signals depend on changes in deoxyhemoglobin content, which is associated with baseline cerebral blood volume (CBV) and blood oxygen saturation change. To accurately interpret activation-induced BOLD responses and quantify perfusion values by BOLD dynamic susceptibility contrast (BOLD-DSC) with transient hypoxia, it is critical to assess Δ R2*$$ {\mathrm{R}}_2^{\ast } $$ values in tissue and blood across varying levels of hypoxia and magnetic field strengths (B₀).

Methods

Whole-brain BOLD responses were examined using 5-s graded hypoxic challenges with 10%, 5%, and 0% O₂ at ultrahigh field strengths of 7 T, 9.4 T, and 15.2 T. Both tissue and blood responses were analyzed for BOLD-DSC quantificat

SUBMITTER: Le TT 

PROVIDER: S-EPMC12021331 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature