Three-Dimensional Vector MR Elastography for Evaluating Tissue Mechanical Heterogeneity to Assess Liver Disease...

Area of Science:

• Hepatology
• Medical Imaging
• Biomarker Development

Background:

• Metabolic dysfunction-associated steatotic liver disease (MASLD) presents a significant global health burden.
• Hepatic inflammation and fibrosis in MASLD are known to be heterogeneous processes.

Purpose of the Study:

• To quantify liver mechanical property heterogeneity in MASLD using MR elastography (MRE).
• To assess the potential of MRE-derived heterogeneity as a biomarker for liver inflammation and fibrosis severity in MASLD patients.

Main Methods:

• Three-dimensional vector MRE was employed for pixel-wise histogram analysis of shear stiffness and loss modulus.
• Preclinical (n=25 rats) and clinical (n=179 patients) studies were conducted, including analysis of MRE data before and after bariatric surgery.
• Calculations included mean and coefficient of variation (CV) of mechanical properties, correlated with biopsy data, portal pressure, and fibrosis.

Main Results:

• In cirrhotic livers, CV of loss modulus correlated with portal pressure and fibrosis variation (p<0.01).
• Clinical data showed increased CV of shear stiffness and loss modulus with higher fibrosis and inflammation grades, respectively.
• Following bariatric surgery, a significant decrease in CV of shear stiffness was observed after one year (p=0.009).

Conclusions:

• Liver mechanical heterogeneity measured by MRE is positively associated with MASLD progression.
• MRE-derived tissue mechanical heterogeneity shows promise as a biomarker for assessing MASLD severity.
• This approach may also serve to evaluate the efficacy of therapeutic interventions for MASLD.