Accuracy and repeatability of QRAPMASTER and MRF-vFA

Our purpose is to evaluate bias and repeatability of the quantitative MRI sequences QRAPMASTER, based on steady-state imaging, variable Flip Angle MRF (MRF-VFA), transient response. Both techniques are assessed with a standardized phantom five volunteers 1.5 T 3 clinical scanners. All scans were repeated eight times in consecutive weeks. In phantom, mean bias±95% confidence interval for T1 values QRAPMASTER was 10 ± 10% 4 13% 3.0 T. The MRF-vFA 21 17% 9 9% For T2 12 3% 23 1% 17 19 2% estimated lower than MRF-vFA. Repeatability good low coefficients variation (CoV). Mean CoV 95% 3.2 0.4% 4.5 0.8% 2.7% 0.2% 2.5 3.3 1.9% 0.6% 2.0 5.7 1.0% in-vivo range previously reported by other authors. gray matter 1.7 using 0.7 0.5% 0.9 2.4 white 0.3% 1.3 1.1% A GLM analysis showed that variations mainly depend field strength subject, but not follow-up repetition different days. This confirms high summary, both systems highly repeatable moderate accuracy, providing results comparable standard references. While similar methods, more accurate. tested commercial product 4.77 faster, which would ease inclusion relaxometry.