IVIM-based virtual MR elastography for predicting fibrosis severity in rectal cancer: A comparison with conventional MR elastography

Motivation: No imaging marker currently predicts neoadjuvant chemoradiotherapy efficacy in rectal cancer (RC). Goal(s): To generate virtual magnetic resonance elastography (v-MRE) imaging in patients with RC, assess fibrosis, and compare it with real MRE. Approach: Using intravoxel incoherent motion (IVIM) imaging-derived parameters —shear-wave speed ( c) and loss angle (φ), —correlations with shift ADC (sADC) were determined by developing equations for virtual shear-wave speed (Vc) and virtual loss angle (Vφ) to evaluate RC fibrosis. Results: The optimal b0 and 1500 s/mm² combination revealed strong correlations between c, φ, and sADC, supporting v-MRE as a feasible alternative to MRE for diagnosing fibrosis severity. Impact: v-MRE is a reliable alternative to MRE in diagnosing the degree of fibrosis in RC, which may assist clinicians in developing neoadjuvant therapeutic strategies for RC.