title: A tale of two methods: combining near-infrared spectroscopy with MRI for studies of brain oxygenation and metabolism.
abstract: Combining magnetic resonance imaging (MRI) with near-infrared spectroscopy (NIRS) leads to excellent synergies which can improve the interpretation of either method and can provide novel data with respect to measuring brain oxygenation and metabolism. MRI has good spatial resolution, can detect a range of physiological parameters and is sensitive to changes in deoxyhemoglobin content. NIRS has lower spatial resolution, but can detect, and with specific technologies, quantify, deoxyhemoglobin, oxyhemoglobin, total hemoglobin and cytochrome oxidase. This paper reviews the application of both methods, as a multimodal technology, for assessing changes in brain oxygenation that may occur with changes in functional activation state or metabolic rate. Examples of hypoxia and ischemia are shown. Data support the concept of reduced metabolic rate resulting from hypoxia/ischemia and that metabolic rate in brain is not close to oxygen limitation during normoxia. We show that multimodal MRI and NIRS can provide novel information for studies of brain metabolism.
authors.affiliation: Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada. dunnj@ucalgary.ca.|Department of Radiology, University of Calgary, 3330 Hospital Drive, N.W., Calgary, AB, Canada, T2N 4 N1. dunnj@ucalgary.ca.|Experimental Imaging Centre, University of Calgary, Calgary, AB, Canada. dunnj@ucalgary.ca.
authors.forename: Jeff F
authors.initials: JF
authors.lastname: Dunn
authors.affiliation: Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.|Department of Radiology, University of Calgary, 3330 Hospital Drive, N.W., Calgary, AB, Canada, T2N 4 N1.
authors.forename: Nabeela
authors.initials: N
authors.lastname: Nathoo
authors.affiliation: Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.|Department of Radiology, University of Calgary, 3330 Hospital Drive, N.W., Calgary, AB, Canada, T2N 4 N1.
authors.forename: Runze
authors.initials: R
authors.lastname: Yang
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D064847:Multimodal Imaging; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D013552:Swine
chemical_list: D010100:Oxygen