Comparison of non-contrast abbreviated MRI and ultrasound as surveillance modalities for HCC

Background and aims Ultrasonography (US) is recommended for HCC surveillance in high-risk patients, but has limited performance in detecting early-stage HCC. We aimed to compare the diagnostic performance of biannual US and annual non-contrast abbreviated magnetic resonance imaging (NC-AMRI) as HCC surveillance modalities in high-risk patients. Methods This prospective, multicenter cohort study enrolled participants with an estimated annual risk of HCC greater than 5% between October 2015 and April 2017. Participants underwent six rounds of HCC surveillance at 6-month intervals, with both US and NC-AMRI at rounds 1, 3, and 5, and only US at rounds 2, 4, and 6. The sensitivity, diagnostic yield (DY), and false referral rate (FRR) for HCC detection by US and NC-AMRI were compared. Results In total, 208 participants underwent 980 US and 516 NC-AMRI examinations during 30 months of follow-up. Among them, 34 HCCs were diagnosed in 31 participants, with 20 (64.5%) classified as very early and 11 (35.5%) as early-stage. The sensitivity of annual NC-AMRI (71.0%, 22/31) was marginally higher than that of biannual US (45.2%, 14/31; p = 0.077). NC-AMRI showed a significantly higher DY than US (4.26% vs. 1.43%, p < 0.001), with a similar FRR (2.91% vs. 3.06%, p = 0.885). A simulation of alternating US and NC-AMRI at 6-month intervals yielded a sensitivity of 83.0% (26/31), significantly exceeding that of biannual US (p = 0.006). Conclusions Annual NC-AMRI showed a marginally higher sensitivity than biannual US for HCC detection in high-risk patients. The DY of annual NC-AMRI was significantly higher than that of biannual US, without increasing the FRR. Alternating US and NC-AMRI at 6-month intervals could be an optimal surveillance strategy for high-risk patients. Impact and Implications Current guidelines permit the use of magnetic resonance imaging (MRI) as a surveillance tool for hepatocellular carcinoma (HCC) in patients in whom ultrasonography (US) is inadequate. However, the specific indications, imaging sequences, and surveillance intervals for MRI surveillance remain unclear. In our study, we found that annual non-contrast (NC)-abbreviated MRI (AMRI) exhibited marginally higher sensitivity and significantly better diagnostic yield than biannual US in high-risk patients for HCC. Adopting alternating US and NC-AMRI at 6-month intervals demonstrated significantly improved sensitivity compared to biannual US, making it a potentially optimal surveillance strategy for high-risk patients. Clinical Trial Number ClinicalTrials.gov Identifier: NCT02551250