Diagnostic performance and interreader agreement of CEUS LI-RADS in ≤ 30 mm liver nodules with different experienced radiologists

Purpose To explore the diagnostic performance and interreader agreement of CEUS LI-RADS in diagnosing ≤ 30 mm liver nodules with different experienced radiologists. Methods Between January 2018 and October 2020, 244 patients at high-risk for HCC who underwent CEUS were enrolled. Two novice radiologists and two expert radiologists independently evaluated LI-RADS categories and main features. Kappa ( κ ) and Kendall’s tests were employed to evaluate the interreader agreement of CEUS LI-RADS. The diagnostic performance was determined based on sensitivity, specificity, accuracy, PPV and NPV. Results The interreader agreement for arterial phase hyperenhancement, late and mild washout, early washout, and rim hyperenhancement was moderate to almost perfect ( κ , 0.44–0.93) among the different levels of radiologists. The interreader agreement for the LI-RADS categories was substantial to almost perfect ( κ , 0.78–0.88). However, the interreader agreement for marked washout was fair to moderate ( κ , 0.28–0.50). When CEUS LR-5 was used as a diagnostic criterion for HCC, there were no statistical differences in sensitivity, specificity, accuracy, PPV and NPV among the radiologists ( p > 0.05), except for the differences between Reader 4 and the remaining three radiologists in terms of accuracy and sensitivity ( p < 0.05). Conclusion CEUS LI-RADS has good diagnostic agreement for ≤ 30 mm liver nodules among experienced radiologists.