title: Test-retest reproducibility of a rapid method to measure brain oxygen metabolism.
abstract: Cerebral metabolic rate of oxygen (CMRO(2)) is an important index of tissue viability and brain function, but this parameter cannot yet be measured routinely on clinical scanners. Recently, a noninvasive technique was proposed which estimates global CMRO(2) by concomitantly measuring oxygen-extraction-fraction using T(2)-relaxation-under-spin-tagging MRI and pulse oximetry, and cerebral-blood-flow using phase-contrast MRI. This study sought to establish a standard acquisition procedure for this technique and to evaluate its test-retest reproducibility in healthy subjects. Each subject was examined in five sessions and each session included two measurements. Intrasession, intersession, and intersubject coefficients of variation for CMRO(2) were found to be 3.84 ± 1.44% (N = 7, mean ± standard deviation), 6.59 ± 1.56%, and 8.80% respectively. These reproducibility values were comparable or slightly superior to (15) O positron emission tomography (PET) results reported in the literature. It was also found that oxygen-extraction-fraction and cerebral-blood-flow tended to co-vary across sessions (P = 0.002) and subjects (P = 0.01), and their coefficients of variation were greater than that of CMRO(2). The simplicity and reliability features may afford this global CMRO(2) technique great potential for immediate clinical applications.
authors.affiliation: Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
authors.forename: Peiying
authors.initials: P
authors.lastname: Liu
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.forename: Hanzhang
authors.initials: H
authors.lastname: Lu
mesh_terms: D000328:Adult; D000465:Algorithms; D001921:Brain / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D010100:Oxygen