Reproducibility of CMRO 2 determination using dynamic 17 O MRI

Purpose To assess the reproducibility of 17 O MRI‐based determination of the cerebral metabolic rate of oxygen consumption (CMRO 2 ) in healthy volunteers. To assess the influence of image acquisition and reconstruction parameters on dynamic quantification of functional parameters such as CMRO 2 . Methods Dynamic 17 O MRI data were simulated and used to investigate influences of temporal resolution (Δt) and partial volume correction (PVC) on the determination of CMRO 2 . Three healthy volunteers were examined in two separate examinations. In vivo 17 O MRI measurements were conducted with a nominal spatial resolution of (7.5 mm) 3 using a density‐adapted radial sequence with golden angle acquisition scheme. In each measurement, 4.0 ± 0.1 L of 70%‐enriched 17 O gas were administered using a rebreathing system. Data were corrected with a PVC algorithm, and CMRO 2 was determined in gray matter (GM) and white matter (WM) compartments using a three‐phase metabolic model (baseline, 17 O inhalation, decay phase). Results Comparison with the ground truth of simulations revealed improved CMRO 2 determination after application of PVC and with Δt ≤ 2:00 min. Evaluation of in vivo data yields to CMRO 2,GM  = 2.31 ± 0.1 μmol/g/min and to CMRO 2,WM  = 0.69 ± 0.04 μmol/g/min with coefficients of variation (CoV) of 0.3–5.5% and 4.3–5.0% for intra‐volunteer and inter‐volunteer data, respectively. Conclusion This in vivo 17 O inhalation study demonstrated that the proposed experimental setup enables reproducible determination of CMRO 2 in healthy volunteers. Magn Reson Med 79:2923–2934, 2018. © 2017 International Society for Magnetic Resonance in Medicine.