The first portion of the proposal involves the development of a QC algorithm assessing MR data quality and test-retest. The investigators will propose solutions to improve data acquisition and processing. The last 2 years of the study will be dedicated to a prospective randomized study comparing Yttrium 90 radioembolization to sorafenib, assessing the role of baseline MRI metrics and early changes (at 2 weeks) in these metrics as markers of tumor response and time to progression in patients with unresectable HCC.