Evaluation of contrast-enhanced ultrasound LI-RADS version 2017: application on 271 liver nodules in individuals with non-alcoholic steatohepatitis

Objectives: To evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) version 2017 in a population with non-alcoholic steatohepatitis (NASH).

Methods: Between January 2013 and December 2020, consecutive patients diagnosed with NASH with untreated liver nodules were enrolled in this retrospective study. A prospective evaluation was performed between January 2021 and August 2021 as a validation set. Diagnostic performance was assessed.

Results: We included 217 nodules in 211 patients (mean age, 49.7 ± 21.7 years; male, 156) in the retrospective study. The positive predictive value (PPV) of CEUS LR-5 in the diagnosis of hepatocellular carcinoma (HCC) was 70.8% (56/79). In total, 28 of 217 (12.9%) nodules were classified as LR-M, of which 12 showed arterial phase hyper-enhancement, early washout, and absence of a punched-out appearance within 5 min; 10 of the 12 (83%) were HCC. When these nodules were reclassified as LR-5, the specificity of LR-M as a predictor of non-HCC malignancy increased from 91.0 (181/199) to 96.5% (192/199) (p = .023). Despite the reclassification, LR-5 specificity and PPV remained high (80.6% and 72.5%, respectively). Following reclassification, LR-M specificity increased from 90.0 (45/50) to 100% (50/50) (p = .022) in the validation set.

Conclusion: CEUS LI-RADS category LR-5 is effective in predicting the presence of HCC. In NASH patients, diagnostic performance can be further improved by reclassifying LR-M nodules with arterial phase hyper-enhancement, early washout, and punched-out appearance as LR-5.

Key points: • The LI-RADS classification of CEUS has a high application value for differentiation of HCC in NASH patients. • When LR-M nodules with arterial phase hyperenhancement and early washout but not punched-out appearance at < 5 min are reclassified as LR-5; the modification of LI-RADS has a better performance. • The PPV of modified LR-5 in the non-cirrhotic group was better than that of LR-5. The PPV of modified CEUS LR-5 in the non-cirrhotic group was comparable to that in the cirrhotic group (p both = 0.065).