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Reproducibility of QQ (QSM + qBOLD) Oxygen Extraction Fraction (OEF) Mapping in the Brain at 3 and 1.5 T
Hangwei Zhuang1,2, Kofi Deh3, Alexey Dimov1
1Department of Radiology, Weill Cornell Medical College, New York, New York, USA.
Purpose:
This study aims to assess the repeatability and reproducibility of qBOLD+QSM (QQ) oxygen extraction fraction (OEF) measurements across 3 and 1.5 T.
Methods:
The effects of field strength on signal to noise ratio (SNR) and OEF sampling time were experimentally assessed in 14 healthy subjects using repeated scans performed at 3 and 1.5 T. Whole-brain and regional OEF values were analyzed using Bland-Altman and correlation between repeated scans and across field strengths.
Results:
Whole-brain and regional OEF values showed strong agreement between repeated scans at the same field strength, with minimal differences (≤ 0.74%) and high correlation (r > 0.92). Across field strengths, comparisons similarly showed small mean differences (≤ 1.51%) and strong correlations (r > 0.95).
Conclusion:
QQ-OEF has good repeatability and reproducibility at both 3 and 1.5 T. Good performance at 1.5 T may arise from accurate noise modeling and longer sampling times at lower field strengths.
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