Standardizing quantitative muscle MRI: an inter-vendor evaluation in healthy adults

Area of Science:

• Medical Imaging
• Neurology
• Biophysics

Background:

• Quantitative muscle MRI (qMRI) is crucial for detecting muscular alterations in neuromuscular diseases (NMDs).
• Multi-center studies are vital for rare NMD research, demanding comparable data across different MRI vendors.
• Manufacturer-related variability in qMRI parameters remains underexplored.

Purpose of the Study:

• To evaluate the inter-vendor reproducibility of qMRI parameters in healthy subjects.
• To assess manufacturer-related variability in qMRI measurements.
• To inform data harmonization for multi-center NMD studies.

Main Methods:

• Ten healthy volunteers underwent qMRI on Siemens and Philips 3T systems within one week.
• Analyzed twelve leg muscles using Dixon (fat fraction, FF), T2 mapping (water T2, wT2), and diffusion-weighted imaging (FA, MD, RD, λ1).
• Reproducibility assessed via ICC, coefficient of variation, t-tests, and Bland-Altman analysis.

Main Results:

• Most qMRI parameters demonstrated moderate to excellent reproducibility (e.g., ICC_FF=0.923, ICC_wT2=0.792).
• Axial diffusivity (λ1) showed poor reproducibility (ICC=0.361).
• Significant inter-vendor differences (p<0.05) were observed for all parameters, with biases from 3.6% (FA) to 44.2% (FF).

Conclusions:

• qMRI parameters are generally reproducible within healthy volunteers.
• Absolute qMRI values differ significantly between manufacturers, requiring correction for accurate data pooling.
• Addressing manufacturer-related discrepancies is essential for reliable multi-center and longitudinal NMD research.