Bias, Repeatability and Reproducibility of Liver T₁ Mapping With Variable Flip Angles

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Medical Imaging Techniques
• Quantitative MRI

Background:

• Three-dimensional variable flip angle (VFA) methods are standard for liver T1 mapping.
• Limited data exists on the accuracy, repeatability, and reproducibility of VFA T1 mapping in the liver across different MRI vendors.
• This study addresses the need for multivendor data on VFA T1 liver mapping.

Purpose of the Study:

• To evaluate the bias, repeatability, and reproducibility of liver T1 mapping using VFA techniques.
• To assess the performance of VFA T1 mapping in a multivendor MRI setting.

Main Methods:

• Prospective observational study involving eight healthy volunteers.
• Scans were performed on six MRI scanners from three different vendors at 1.5-T and 3.0-T field strengths.
• Volunteers underwent repeated scanning sessions with standardized pre-scan instructions.

Main Results:

• The 95% confidence interval for mean bias was 34 ± 6%, and for mean repeatability relative error was 10 ± 3%.
• Mean reproducibility relative error was 29 ± 7% at 1.5-T and 25 ± 4% at 3.0-T.
• These results indicate acceptable performance across scanners and field strengths.

Conclusions:

• The bias, repeatability, and reproducibility of VFA T1 mapping in the liver are comparable to findings in other organs like the brain, prostate, and breast.
• VFA T1 mapping demonstrates consistent performance in a multivendor environment, supporting its clinical utility for liver assessment.