Research progress of virtual magnetic resonance elastography.

Tissue stiffness assessment plays a critical role in the clinical diagnosis of liver fibrosis and the differentiation of benign from malignant tumors, among other conditions. Conventional magnetic resonance elastography (MRE) enables noninvasive evaluation of tissue stiffness but relies on dedicated external vibration devices, which limits its widespread clinical adoption. Virtual magnetic resonance elastography (vMRE) has emerged as a promising branch of MRE and has attracted increasing attention in recent years. vMRE is primarily based on microstructural analysis using diffusion-weighted imaging (DWI), from which virtual shear modulus is derived by modeling water molecule diffusion, thereby eliminating the need for additional mechanical excitation hardware. Tissue elastic parameters can also be estimated from conventional MRI sequences, offering advantages in convenience and compatibility. However, the diagnostic performance of vMRE relative to conventional MRE remains controversial. Existing studies are mostly small-sample, single-center investigations, and both the models and scanning protocols have yet to be standardized. Systematic reviews and standardized guidelines are still lacking. This article reviews the technical characteristics, application progress, influencing factors, and optimization strategies of vMRE, aiming to provide a reference for its clinical translation and future research.