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Purpose To determine whole-brain cerebral metabolic rate of oxygen (CMRO2), an improved imaging approach, based on radial encoding, termed radial OxFlow (rOxFlow), was developed to simultaneously quantify draining vein venous oxygen saturation (SvO2) and total cerebral blood flow (tCBF). Methods To evaluate the efficiency and precision of the rOxFlow sequence, 10 subjects were studied during a paradigm of repeated breath-holds with both rOxFlow and Cartesian OxFlow (cOxFlow) sequences. CMRO2 was calculated at baseline from OxFlow-measured data assuming an arterial O2 saturation of 97%, and the SvO2 and tCBF breath-hold responses were quantified. Results Average neurometabolic-vascular parameters across the 10 subjects for cOxFlow and rOxFlow were, respectively: SvO2 (%) baseline: 64.6 ± 8.0 versus 64.2 ± 6.6; SvO2 peak: 70.5 ± 8.5 versus 72.6 ± 5.4; tCBF (mL/min/100 g) baseline: 39.2 ± 3.8 versus 40.6 ± 8.0; tCBF peak: 53.2 ± 5.1 versus 56.1 ± 11.7; CMRO2 (µmol O2/min/100 g) baseline: 111.5 ± 26.8 versus 120.1 ± 19.6. The above measures were not significantly different between sequences (P > 0.05). Conclusion There was good agreement between the two methods in terms of the physiological responses measured. Comparing the two, rOxFlow provided higher temporal resolution and greater flexibility for reconstruction while maintaining high SNR. Magn Reson Med 79:217–223, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Purpose In this work, we compare susceptometry-based oximetry (SBO) and two T2-based methods for estimating resting baseline SvO2 in the superior sagittal sinus (SSS). Methods SBO is a field-mapping technique whereas in T2-based methods the intravascular blood signal is isolated either with velocity-encoded projections [projection-based T2 (PT2)] or a tag-control scheme [T2-relaxation under spin tagging (TRUST)] after T2-preparation. The measurements were performed on twelve healthy subjects (mean age = 33 ± 6 years) at 3 Tesla field strength. The reliability, precision, and reproducibility were examined for the three techniques. Results The mean (± standard deviation) SvO2 quantified by SBO, PT2, and TRUST were found to be 65.9 ± 3.3, 65.6 ± 3.5, and 63.2 ± 4.1%. The standard deviation (SD) for 10 consecutive measurements in the quantified SvO2 was less than 2.7%, 4.7%, and 5.0% for SBO, PT2, and TRUST across all subjects. In testing reproducibility across different days, the resulting SDs were 2.6, 3.5, and 2.0% for SBO, PT2, and TRUST. Conclusion The results indicate that all three SvO2 quantification techniques to be reliable with good agreement between PT2 and SBO while TRUST yielded slightly lower values compared with the other two techniques. Magn Reson Med 73:2122–2128, 2015. © 2014 Wiley Periodicals, Inc.

In this work, we compare susceptometry-based oximetry (SBO) and two T2 -based methods for estimating resting baseline SvO2 in the superior sagittal sinus (SSS).SBO is a field-mapping technique whereas in T2 -based methods the intravascular blood signal is isolated either with velocity-encoded projections [projection-based T2 (PT2 )] or a tag-control scheme [T2 -relaxation under spin tagging (TRUST)] after T2 -preparation. The measurements were performed on twelve healthy subjects (mean age = 33 ± 6 years) at 3 Tesla field strength. The reliability, precision, and reproducibility were examined for the three techniques.The mean (± standard deviation) SvO2 quantified by SBO, PT2 , and TRUST were found to be 65.9 ± 3.3, 65.6 ± 3.5, and 63.2 ± 4.1%. The standard deviation (SD) for 10 consecutive measurements in the quantified SvO2 was less than 2.7%, 4.7%, and 5.0% for SBO, PT2 , and TRUST across all subjects. In testing reproducibility across different days, the resulting SDs were 2.6, 3.5, and 2.0% for SBO, PT2 , and TRUST.The results indicate that all three SvO2 quantification techniques to be reliable with good agreement between PT2 and SBO while TRUST yielded slightly lower values compared with the other two techniques.