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Quantitative mapping of cerebral metabolic rate of oxygen (CMRO 2 ) using quantitative susceptibility mapping (QSM)
Author(s) -
Zhang Jingwei,
Liu Tian,
Gupta Ajay,
Spincemaille Pascal,
Nguyen Thanh D.,
Wang Yi
Publication year - 2015
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25463
Subject(s) - quantitative susceptibility mapping , cerebral blood flow , chemistry , white matter , nuclear magnetic resonance , cerebral perfusion pressure , nuclear medicine , magnetic resonance imaging , medicine , cardiology , physics , radiology
Purpose To quantitatively map cerebral metabolic rate of oxygen (CMRO 2 ) and oxygen extraction fraction ( OEF ) in human brains using quantitative susceptibility mapping (QSM) and arterial spin labeling‐measured cerebral blood flow (CBF) before and after caffeine vasoconstriction. Methods Using the multiecho, three‐dimensional gradient echo sequence and an oral bolus of 200 mg caffeine, whole brainCMRO 2and OEF were mapped at 3‐mm isotropic resolution on 13 healthy subjects. The QSM‐basedCMRO 2was compared with anR 2 * ‐basedCMRO 2to analyze the regional consistency within cortical gray matter (CGM) with the scaling in theR 2 *method set to provide same totalCMRO 2as the QSM method for each subject. Results Compared to precaffeine, susceptibility increased (5.1 ± 1.1 ppb; P < 0.01) and CBF decreased (−23.6 ± 6.7 ml/100 g/min; P < 0.01) at 25‐min postcaffeine in CGM. This corresponded to aCMRO 2of 153.0 ± 26.4 μmol/100 g/min with an OEF of 33.9 ± 9.6% and 54.5 ± 13.2% ( P < 0.01) pre‐ and postcaffeine, respectively, at CGM, and aCMRO 2of 58.0 ± 26.6 μmol/100 g/min at white matter.CMRO 2from both QSM‐ andR 2 * ‐based methods showed good regional consistency ( P > 0.05), but quantitation ofR 2 * ‐basedCMRO 2required an additional scaling factor. Conclusion QSM can be used with perfusion measurements pre‐ and postcaffeine vascoconstriction to mapCMRO 2and OEF. Magn Reson Med 74:945–952, 2015. © 2014 Wiley Periodicals, Inc.