Accuracy, repeatability, and interplatform reproducibility of T₁ quantification methods used for DCE-MRI: Results...

Area of Science:

• Magnetic Resonance Imaging
• Quantitative MRI
• Biomedical Engineering

Background:

• Accurate T1 quantification is crucial for dynamic contrast-enhanced MRI (DCE-MRI).
• Standardization of T1 mapping protocols across different MRI platforms and field strengths remains a challenge.
• In vitro assessment of protocol performance is essential before clinical application.

Purpose of the Study:

• To assess the in vitro accuracy, test-retest repeatability, and interplatform reproducibility of T1 quantification protocols.
• To compare common inversion-recovery spin-echo (IR-SE) and variable flip angle (VFA) protocols at 1.5T and 3T.
• To evaluate site-specific T1 mapping protocols.

Main Methods:

• A T1 phantom with 14 samples was imaged across eight centers.
• Common IR-SE and VFA (seven flip angles) protocols were used, alongside site-specific protocols.
• Statistical models assessed factors influencing accuracy and repeatability; coefficients of variation measured interplatform reproducibility.

Main Results:

• Common IR-SE protocol showed good accuracy (1.4-5.5% error) and repeatability (0.2-8.3% error), influenced by sample and scanner, respectively.
• Common VFA protocol accuracy (5.7-32.2% error) and repeatability (0.7-25.8% error) were influenced by field strength and scanner, with lower reproducibility at 3T.
• Site-specific Look-Locker IR and VFA (2-3 flip angles) protocols demonstrated the best performance (errors < 15%).

Conclusions:

• Optimized VFA protocols with 2-3 flip angles provide an acceptable balance of spatial coverage, accuracy, and repeatability for T1 quantification.
• Further improvements in VFA protocol robustness require optimization of flip angle selection and B1 correction.
• Standardization and validation of T1 mapping techniques are essential for reliable DCE-MRI analysis.