How to predict which patients with initially unresectable liver cancer are more likely to respond to conversion therapy remains an important unresolved problem in guiding treatment strategy and surgical timing. Substantial variation exists among patients in their tumor response to the same conversion therapy regimen, and current pretreatment imaging assessment does not adequately capture this inter-individual variability. We hypothesize that baseline tumor viscoelastic parameters measured by three-dimensional magnetic resonance elastography (3D-MRE) differ substantially across patients, and that this inter-individual heterogeneity may be associated with differential response to conversion therapy. This study aims to prospectively evaluate the association between baseline 3D-MRE-derived tumor viscoelastic parameters and pathological response as well as surgical conversion outcomes across patients with liver cancer receiving conversion therapy.