TY - JOUR
T1 - Noninvasive Measurements of Cerebral Blood Flow, Oxygen Extraction Fraction, and Oxygen Metabolic Index in Human with Inhalation of Air and Carbogen using Magnetic Resonance Imaging
AU - An, Hongyu
AU - Sen, Souvik
AU - Chen, Yasheng
AU - Powers, William J.
AU - Lin, Weili
N1 - Funding Information:
Acknowledgments This study was supported by the Department of Neurology, University of North Carolina at Chapel Hill, grants from National Institute of Health (NIH 5R01NS054079, NIH 5P50NS055977) and American Heart Association (AHA 0730321N).
PY - 2012/6
Y1 - 2012/6
N2 - Noninvasive magnetic resonance (MR) methods have been explored to provide quantitative measurements of cerebral blood flow (CBF), oxygen extraction fraction (OEF), and oxygen metabolic index (OMI = CBF × OEF). In this study, we sought to evaluate whether MR measured OEF, CBF, and OMI can consistently detect the expected physiological changes in humans under normal and hyperoxic hypercapnic conditions. Nine healthy human subjects were scanned while breathing through a mask, alternating inhaled gas in a sequential order as room air, carbogen (3% CO2 mixed with 97% O2), room air, carbogen, and room air. OEF, CBF, and OMI were obtained from the whole brain, gray matter (GM), and white matter (WM) at each gas inhalation state. Similar to previous positron emission tomography findings, our study consistently demonstrated a 10-12% decrease in OEF with a 10% increase of CBF and a stable OMI during carbogen inhalation. Moreover, GM/WM ratio in CBF and OMI remained constant during air and carbogen breathing. In addition, OEF, CBF, and OMI were highly reproducible if the same inhaled gas was used. In summary, our results demonstrate that noninvasive MR measurements can provide reproducible measurements of OEF, CBF, and OMI in normal subjects under normal and altered physiological conditions.
AB - Noninvasive magnetic resonance (MR) methods have been explored to provide quantitative measurements of cerebral blood flow (CBF), oxygen extraction fraction (OEF), and oxygen metabolic index (OMI = CBF × OEF). In this study, we sought to evaluate whether MR measured OEF, CBF, and OMI can consistently detect the expected physiological changes in humans under normal and hyperoxic hypercapnic conditions. Nine healthy human subjects were scanned while breathing through a mask, alternating inhaled gas in a sequential order as room air, carbogen (3% CO2 mixed with 97% O2), room air, carbogen, and room air. OEF, CBF, and OMI were obtained from the whole brain, gray matter (GM), and white matter (WM) at each gas inhalation state. Similar to previous positron emission tomography findings, our study consistently demonstrated a 10-12% decrease in OEF with a 10% increase of CBF and a stable OMI during carbogen inhalation. Moreover, GM/WM ratio in CBF and OMI remained constant during air and carbogen breathing. In addition, OEF, CBF, and OMI were highly reproducible if the same inhaled gas was used. In summary, our results demonstrate that noninvasive MR measurements can provide reproducible measurements of OEF, CBF, and OMI in normal subjects under normal and altered physiological conditions.
KW - Arterial spin labeling
KW - Asymmetric spin echo
KW - Carbogen
KW - Cerebral blood flow
KW - MR measured oxygen metabolic index
KW - Oxygen extraction fraction
UR - http://www.scopus.com/inward/record.url?scp=84861678112&partnerID=8YFLogxK
U2 - 10.1007/s12975-011-0142-9
DO - 10.1007/s12975-011-0142-9
M3 - Article
C2 - 24323780
AN - SCOPUS:84861678112
SN - 1868-4483
VL - 3
SP - 246
EP - 254
JO - Translational Stroke Research
JF - Translational Stroke Research
IS - 2
ER -