Extracellular contrast-enhanced MRI with diffusion-weighted imaging for HCC diagnosis: prospective comparison with gadoxetic acid using LI-RADS

Objectives The aim of this study was to evaluate the diagnostic performance of introducing diffusion-weighted imaging (DWI) as a major feature to extracellular agent (ECA)-MRI for diagnosing HCC in comparison with gadoxetic acid (hepatobiliary agent, HBA)-MRI using Liver Imaging Reporting and Data System (LI-RADS) v2018. Methods This was a prospective intra-individual comparison study using two different types of contrast agents for liver MRI conducted at a tertiary referral academic center. One hundred forty-seven observations in 122 patients at high risk for HCC scheduled for liver surgery were included. The sensitivity, specificity, and accuracy of LI-RADS category 5 (LR-5) for HCC diagnosis according to conventional and modified LI-RADS on ECA- and HBA-MRI were measured and compared. Modified LI-RADS incorporated hyperintensity on DWI as a major feature with ECA-MRI, and hypointensity on transitional phase (TP) and/or hepatobiliary phase (HBP) as washout appearance on HBA-MRI, respectively. Results Modified LI-RADS on ECA-MRI had higher sensitivity and accuracy than modified LI-RADS on HBA-MRI (90.3% vs. 74.9%, p