Heterogeneity of Microbubble Accumulation: A Novel Approach to Discriminate Between Well-Differentiated Hepatocellular Carcinomas and Regenerative Nodules

This prospective study aimed to elucidate the possibility of differentiating well-differentiated hepatocellular carcinoma (wHCC) from regenerative nodule (RN) on the basis of the heterogeneity of microbubble accumulation. Intensity analysis was conducted on early-phase and late-phase (60 s and 900 s post-injection; perflubutane microbubble) harmonic sonograms in 33 focal hepatic lesions (≤15 mm; 30 patients with chronic liver disease) that were histologically proven as wHCC or RN. Heterogeneity of enhancement, an average of standard deviation of late-phase enhancement in three different sections in the lesions with late-phase iso-enhancement, was examined with respect to the histologic findings. Heterogeneity of enhancement was higher in wHCC (28.7 ± 3.8) than RN (19.8 ± 2.1, p = 0.0213) in the 29 late-phase iso-enhancement lesions. The best cut-off value of the heterogeneity for the diagnosis of wHCC was 25.58, and the sensitivity and specificity were 77.8% and 100%, respectively. A novel parameter, heterogeneity of microbubble accumulation, facilitates differentiation between wHCC and RN showing a late-phase, iso-enhancement appearance.