Measurement of brain oxygenation changes using dynamic T1-weighted imaging

• Published in: NeuroImage (Orlando, Fla.) Vol. 78; pp. 7 - 15
• Main Authors: Haddock, Bryan, Larsson, Henrik B.W., Hansen, Adam E., Rostrup, Egill
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.09.2013; Elsevier; Elsevier Limited
• Subjects: Biological and medical sciences; Blood; BOLD; Brain oxygenation; Fundamental and applied biological sciences. Psychology; Hyperoxia; MRI; NMR; Nuclear magnetic resonance; Oxygen; Studies; T1-weighted oxygenation level dependent (TOLD); Tumors; Vertebrates: nervous system and sense organs; PbtO2; T1-weighted oxygenation level dependent (TOLD); PaO2; PcO2; TOLD; MRI; CBF; CBV; Hyperoxia; Brain oxygenation; BOLD; T; Imaging; Central nervous system; Nuclear magnetic resonance imaging; weighted oxygenation level dependent (TOLD); Encephalon
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2013.03.068

Magnetic resonance imaging (MRI) has proven useful in evaluating oxygenation in several types of tissue and blood. This study evaluates brain tissue oxygenation changes between normoxia and hyperoxia in healthy subjects using dynamic T1 and T2*-weighted imaging sequences. The change in FiO2 induced by hyperoxia caused a significant decrease in T1. A model to determine changes in tissue oxygen tension from the T1-weighted MRI signal is presented based on previous findings that T1 is sensitive to oxygen tension whereas T2* is sensitive to blood saturation. The two sequences produce results with different regional and temporal dynamics. These differences combined with results from simulations of the T1 signal intensities, indicate an increase in extravascular oxygen tension during hyperoxia. This study concludes that T1 and T2* responses to FiO2 serve as independent biomarkers of oxygen physiology in the brain with a potential to provide quantitative information on tissue oxygenation. •We evaluate intra- and extravascular brain oxygenation with new MRI technique.•We present a model to quantify extravascular changes in oxygen tension from MRI.•Found an increase in extravascular tissue oxygenation for white and grey matter•Two MRI sequences showed different intravascular and extravascular responses.•Model calculates a change in oxygen tension close to literature values.