In vivo quantification of cerebral r2*-response to graded hyperoxia at 3 tesla.

摘要: Objectives: This study aims to quantify the response of transverse relaxation rate magnetic resonance (MR) signal cerebral tissue in healthy volunteers administration air with step-wise increasing percentage oxygen. Materials and Methods: The (R2*) MR was quantified seven under respiratory intake normobaric gas mixtures containing 21, 50, 75, 100% oxygen, respectively. End-tidal breath composition, arterial blood saturation (SaO 2 ), heart pulse were monitored during challenge. R2* maps computed from multi-echo, gradient-echo imaging (MRI) data, acquired at 3.0T. average values segmented white matter (WM) gray (GM) tested by analysis variance (ANOVA), Bonferroni post-hoc correction. GM R2*-reactivity hyperoxia modeled using Hill's equation. Results: Graded resulted a progressive significant ( P -1 . At 75% O supply, had reached level, 16.4 ± 0.7 s = 0.02), without further decrease for R2*-response correlated positively CO partial pressure (R 0.69 0.19) negatively SaO -0.74 0.17). WM showed similar progressive, but non-significant, rates, an increase oxygen 0.055). model predicted maximum GM, 3.5%, half 68% concentration. Conclusions: GM-R2* responds concentration-dependent manner, suggesting that monitoring modeling may provide new oxygenation biomarkers tumor therapy or assessment cerebrovascular reactivity patients.