To evaluate the diagnostic performance of contrast-enhanced ultrasound and contrast-enhanced MRI for well-differentiated hepatocellular carcinoma (HCC) and dysplastic nodules (DNs).

Thirty-nine patients with 39 well-differentiated HCC and seven patients with eight DNs pathologically confirmed who underwent contrast-enhanced ultrasound (CEUS) and enhanced MRI at Zhongshan Hospital of Fudan University from January 2012 to December 2018 were enrolled. Imaging features and diagnostic efficacy of the two imaging methods were analyzed. Chi-square test and Kappa value were used to compare the consistency of the two imaging methods. Receiver operator characteristic (ROC) curve analysis was performed to calculate the diagnostic efficiency of the two imaging methods.

For the two imaging methods, the consistency of arterial phase enhancement patterns of well-differentiated HCC was 69.2% (27/39) and Kappa value was 0.482. The consistency of late phase enhancement patterns of well-differentiated HCC was 53.8% (21/39) and Kappa value was 0.168. The major enhancement pattern of DNs was "iso-enhancement~iso-enhancement" on CEUS, and "hyperintensity~hypointensity" on contrast-enhanced MRI. No DNs exhibited washout in the late phase on CEUS. Among the four examination methods, CEUS, enhanced MRI, and CEUS combined with enhanced MRI (detected by both or by either), the sensitivity (66.7%) and accuracy (61.7%) of CEUS combined with enhanced MRI (detected by either) were highest for the diagnosis of well-differentiated HCC, while CEUS had the highest specificity (100%) and area under the ROC curve (0.658, 95%CI: 0.482-0.834).

CEUS combined with enhanced MRI is helpful for differential diagnosis of well-differentiated HCC and DNs, while CEUS has a higher specificity.