title: Comparison of MRI methods for measuring whole-brain venous oxygen saturation.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
authors: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors: Suliman
authors: S
authors: Barhoum
authors: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors: Zachary B
authors: ZB
authors: Rodgers
authors: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors: Michael
authors: M
authors: Langham
authors: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors: Jeremy F
authors: JF
authors: Magland
authors: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors: Cheng
authors: C
authors: Li
authors: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors: Felix W
authors: FW
authors: Wehrli
mesh_terms: D000328:Adult; D001921:Brain / Q000378:metabolism*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D015203:Reproducibility of Results
chemical_list: D010100:Oxygen
keywords: SvO2 quantification; T2-relaxation-under-spin tagging; blood T2 quantification; brain oximetry; susceptometry-based oximetry