Use of gadoxetic acid–enhanced liver MRI and mortality in more than 30000 patients with hepatocellular Carcinoma: A nationwide analysis

Background: The impact on survival of gadoxetic acid–enhanced MRI in addition to multiphase contrast material–enhanced CT for initial staging in patients with hepatocellular carcinoma (HCC) is unknown. Purpose: To compare all-cause mortality in patients with HCC who underwent CT only, CT plus non–gadoxetic acid–enhanced MRI, or CT plus gadoxetic acid–enhanced MRI as part of their initial diagnostic work-up. Materials and Methods: The authors performed a nationwide retrospective cohort study of patients diagnosed with HCC in South Korea between January 2008 and December 2010. Follow-up extended through December 2014. The primary outcome was all-cause mortality. Cox proportional hazards regression model with adjustment of confounding factors was used to estimate hazard ratios (HRs) for all-cause mortality. Results: Among 30 023 patients with HCC (mean age 6 standard deviation, 58.5 years 6 10.7, 23 978 men), the proportions of patients in whom HCC was diagnosed using CT only, CT plus non–gadoxetic acid–enhanced MRI, and CT plus gadoxetic acid–enhanced MRI were 56.1%, 12.9%, and 31.0%, respectively. In adjusted analysis using CT only as the reference category, the HR for mortality for CT plus gadoxetic acid–enhanced MRI was 0.64 (95% confidence interval [CI]: 0.62, 0.67; P , .001), and the HR for CT plus non–gadoxetic acid–enhanced MRI was 0.71 (95% CI: 0.68, 0.75; P , .001). Use of CT plus gadoxetic acid–enhanced MRI was associated with lower mortality compared with CT plus non–gadoxetic acid–enhanced MRI (adjusted HR, 0.90; 95% CI: 0.85, 0.95; P , .001), but this survival advantage was restricted to patients with localized disease. Conclusion: In patients with hepatocellular carcinoma, additional use of contrast-enhanced MRI was associated with lower mortality. Furthermore, CT plus gadoxetic acid–enhanced MRI was associated with better survival than CT plus non–gadoxetic acid–enhanced MRI but only in patients with localized disease.