Contrast-enhanced ultrasound liver imaging reporting and data system for diagnosing hepatocellular carcinoma: A meta-analysis

Background & aims: Contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) is a comprehensive system for standardizing CEUS at high risk for hepatocellular carcinoma (HCC). We performed a meta-analysis to determine the diagnostic performance of the CEUS LR-5 for HCC and the pooled proportions of HCCs in each CEUS LI-RADS category. Methods: We searched multiple databases for studies reporting the diagnostic accuracy of the CEUS LI-RADS. Random-effects model was used to determine summary estimates of the diagnostic performance of CEUS LR-5 and the pooled proportions of HCCs in each CEUS LI-RADS category. Risk of bias and concerns regarding applicability were evaluated with the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Results: Eleven studies were included in the final analysis, which consisted of 5535 observations with 3983 HCCs. The pooled per-observation sensitivity and specificity of the CEUS LR-5 for diagnosing HCC were 69% (95% confidence interval [CI], 64%–73%) and 92% (95% CI, 83%–96%) respectively. The pooled proportions of HCCs were 0% (95% CI, 0-0%) for LR-1, 1% (95% CI, 0%–4%) for CEUS LR-2, 26% (95% CI, 14%–39%) for CEUS LR-3, 77% (95% CI, 68%–86%) for CEUS LR-4, 97% (95% CI, 95%–98%) for CEUS LR-5, 57% (95% CI, 44%–69%) for CEUS LR-M and 100% (95% CI, 93%–100%) for CEUS LR-5V or TIV. Conclusions: The CEUS LR-5 category showed moderate sensitivity and high specificity for diagnosing HCC. The proportion of HCCs was higher in the higher CEUS LI-RADS categories.