Diagnostic value of the combining contrast-enhanced ultrasonography and gadoxetic acid-enhanced magnetic resonance imaging in the diagnosis of early hepatocellular carcinoma

Objective To compare the diagnostic efficacies of contrast-enhanced ultrasonography (CEUS) and gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) in the diagnosis of liver nodules ≤2.0 cm in patients with cirrhosis, and to explore the clinical values of combining the arterial phase of CEUS and hepatobiliary phase of EOB-MRI in the diagnosis of early hepatocellular carcinoma (HCC). Methods One hundred and thirteen nodules with diameters lower than 2.0 cm in 98 patients from February to December 2016 in Tianjin Third Central Hospital were included in this retrospective study. The enhancement patterns of nodules in CEUS and EOB-MRI were analyzed. The reference standard was pathological diagnosis or substantial lesion growth at a follow-up of at least 6 months. The efficiencies of CEUS and EOB-MRI in the diagnosis of liver lesions with a diameter lower than 2.0 cm were compared. A new diagnostic strategy, which combines the arterial phase of CEUS and hepatobiliary phase of EOB-MRI was presented to diagnose the early HCC in this study. Results The area under the ROC curve of CEUS and EOB-MRI were 0.858 and 0.814(P>0.05), the sensitivity were 79.1%, 81.4%, specificity were 92.6%, 81.5% and diagnostic accuracy were 82.3% and 81.4%, respectively. By combination of CEUS and EOB-MRI, the area under the ROC curve was 0.831, without difference from CEUS, EOB-MRI (0.831 vs 0.858, 0.814; all P>0.05); its sensitivity was 66.3%, specificity was 100% and diagnostic accuracy was 74.3%. The area under the ROC curve of the new diagnostic strategy, combining the arterial phase of CEUS and hepatobiliary phase of EOB-MRI was 0.934, which was larger than that of CEUS, EOB-MRI and the combination of CEUS and EOB-MRI(0.934 vs 0.858, 0.814, 0.831; all P<0.05). The sensitivity, specificity and diagnostic accuracy of new strategy were 94.2%, 92.6% and 93.8%, respectively. Conclusions The new diagnostic strategy based on the arterial phase of CEUS and hepatobiliary phase of EOB-MRI improves the sensitivity and accuracy in detecting small lesions, which can be used as a complementary diagnostic enhancement pattern for lesions with an atypical enhancement pattern in CEUS or EOB-MRI. Key words: Contrast-enhanced ultrasonography; Gadoxetic acid-enhanced magnetic resonance imaging; Micro hepatocellular carcinoma; Diagnosis