Objective: To perform a meta-analysis of contrast-enhanced ultrasound (CEUS) as a diagnostic tool for small hepatocellular carcinoma (HCC) in patients with cirrhosis.
Methods: A computer-based retrieval system was first used to identify reports on the diagnostic efficacy of CEUS for small HCC in patients with cirrhosis that were published between 1995 and April 2012 in the following literature databases: Medline, PubMed, Foreign Medical Journal Service (FMJS), China National Knowledge Infrastructure (CNKI), VIP Journal Integration Platform (VJIP), Wanfang Chinese Periodical Database, and Chinese Biomedicine Database (CBM). Two investigators, working independently, then selected cases from the relevant based upon specific inclusion and exclusion criteria. The extracted data was subjected to quality assessment of diagnostic accuracy studies (QUADAS). The MetaDisc version 1.4 software was used to conduct meta-analyses.
Results: Six studies, involving 380 lesions detected by various contrast mediums, were selected for analysis. Diagnosis of small HCC in patients with cirrhosis by CEUS based on Sonovue and Levovist had pooled sensitivities of 0.73 (95% confidence interval (CI): 0.67-0.79) and 0.76 (95% CI: 0.60-0.89), pooled specificities of 0.89 (95% CI: 0.81-0.94) and 0.79 (95% CI: 0.61-0.91), pooled positive likelihood ratios of 6.53 (95% CI: 2.74-15.52) and 3.60 (95% CI: 1.89-6.85), pooled negative likelihood ratios of 0.26 (95% CI: 0.13-0.54) and 0.21 (95% CI: 0.02-2.63), and pooled diagnostic odds ratios of 27.50 (95% CI: 7.99-94.72) and 25.74 (95% CI: 5.30-125.04), respectively. The area under the curve of the summary receiving operating characteristic (SROC) of CEUS based on Sonovue was 0.9252 and the Q* index was 0.8595.
Conclusion: CEUS is a valuable diagnostic tool for small HCC in cirrhotic patients.