Reproducibility of CMRO2 determination using dynamic 17O MRI

5 years ago

Reproducibility of CMRO2 determination using dynamic 17O MRI

Mark E. Ladd, Reiner Umathum, Daniel Paech, Peter Bachert, Armin M. Nagel, Jonathan M. Lommen, Sebastian C. Niesporek, Nicolas G.R. Behl

Purpose To assess the reproducibility of 17O MRI-based determination of the cerebral metabolic rate of oxygen consumption (CMRO2) in healthy volunteers. To assess the influence of image acquisition and reconstruction parameters on dynamic quantification of functional parameters such as CMRO2. Methods Dynamic 17O MRI data were simulated and used to investigate influences of temporal resolution (Δt) and partial volume correction (PVC) on the determination of CMRO2. Three healthy volunteers were examined in two separate examinations. In vivo 17O 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 17O gas were administered using a rebreathing system. Data were corrected with a PVC algorithm, and CMRO2 was determined in gray matter (GM) and white matter (WM) compartments using a three-phase metabolic model (baseline, 17O inhalation, decay phase). Results Comparison with the ground truth of simulations revealed improved CMRO2 determination after application of PVC and with Δt ≤ 2:00 min. Evaluation of in vivo data yields to CMRO2,GM = 2.31 ± 0.1 μmol/g/min and to CMRO2,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 17O inhalation study demonstrated that the proposed experimental setup enables reproducible determination of CMRO2 in healthy volunteers. Magn Reson Med, 2017. © 2017 International Society for Magnetic Resonance in Medicine.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/mrm.26952