Elastography and Contrast-enhanced Ultrasonography in the Early Detection of Hepatocellular Carcinoma in an Experimental Model of Nonalcoholic Steatohepatitis

Abstract

The early detection of focal hepatic lesions using ultrasound scanning is challenging, and this challenge becomes even greater in the presence of diffuse parenchymal disease. This study aimed to evaluate the diagnostic performance of elastography and contrast-enhanced ultrasonography (CEUS) in the early detection of hepatocellular lesions in an experimental rat model of nonalcoholic steatohepatitis (NASH). B-mode and Doppler ultrasonography was performed weekly in 30 rats divided into a NASH group (n=20) and a group without liver disease (n=10). The animals underwent elastography and CEUS and were then euthanized. Liver nodules were assessed by histopathology. Doppler mapping results of lesions with vascularization were considered indicative of malignancy, with a sensitivity of 29% before and 71% after contrast injection. The specificity was 71% before and 96% after CEUS. Elastograms of positive lesions showed areas of high stiffness, which were indicative of malignancy. This malignancy was confirmed by the histologic evaluation, with a sensitivity of 90% and a specificity of 60%. After CEUS analysis, 4 nodules were identified that were not observed on B-mode ultrasonography. Early wash-in was significantly associated with malignancy (sensitivity of 88% and specificity of 67%). Both techniques allow for the correct diagnosis of well-differentiated to moderately differentiated hepatocellular carcinomas with good accuracy in an experimental rat model of NASH.