Analysis of liver viscosity behavior as a function of multifrequency magnetic resonance elastography (MMRE)...

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Rheology

Background:

• Liver fibrosis assessment is crucial for disease management.
• Non-invasive methods for evaluating liver tissue properties are highly sought after.
• Viscoelastic properties offer a potential window into liver health.

Purpose of the Study:

• To investigate the diagnostic relevance of liver viscosity measurements.
• To compare different postprocessing methods for magnetic resonance elastography (MRE).
• To analyze the relationship between liver viscoelasticity and fibrosis stage.

Main Methods:

• Fibroscan and multifrequency magnetic resonance elastography (MMRE) were performed on 40 subjects.
• MMRE utilized a pneumatic driver at 60, 70, and 80 Hz.
• Phase images were analyzed using two postprocessing methods: without (Method 1) and with an inversion algorithm (Method 2).
• Rheological models (Voigt, springpot) characterized viscoelastic properties (viscosity: η, elasticity: μ).

Main Results:

• Liver viscous tendency (G″MRE_M2) and viscosity (ηmodels_M1) increased with fibrosis stage without inversion algorithm.
• Viscosity (ηmodels_M2) remained constant with fibrosis stage when using an inversion algorithm.
• Both experimental and rheological elasticities (μMRE_M1, G'MRE_M2, μmodels_M2, μmodels_M1) consistently increased with fibrosis stage.

Conclusions:

• Liver viscosity's behavior is highly dependent on the postprocessing method used.
• Elasticity measurements appear more robust across different postprocessing techniques.
• Further research is needed to establish the clinical relevance of liver viscosity as a diagnostic marker.