Multiparametric Quantitative Ultrasound as a Potential Imaging Biomarker for Noninvasive Detection of Nonalcoholic Steatohepatitis: A Clinical Feasibility Study

<b>Objectives</b>: The FibroScan-aspartate transaminase (AST) score (FAST score) is a hybrid biomarker combining ultrasound and blood test data for identifying nonalcoholic steatohepatitis (NASH). This study aimed to assess the feasibility of using quantitative ultrasound (QUS) biomarkers related to hepatic steatosis for NASH detection and to compare their diagnostic performance with the FAST score. <b>Methods</b>: A total of 137 participants, comprising 71 individuals with NASH and 66 with non-NASH (including 49 normal controls), underwent FibroScan and ultrasound exams. QUS imaging features (Nakagami parameter <i>m</i>, homodyned-K parameter <i>μ</i>, entropy <i>H</i>, and attenuation coefficient <i>α</i>) were extracted from backscattered radiofrequency data. A weighted QUS parameter based on <i>m</i>, <i>μ</i>, <i>H</i>, and <i>α</i> was derived via linear discriminant analysis. NASH was diagnosed based on liver biopsy findings using the nonalcoholic fatty liver disease activity score (NAS). Diagnostic performance was evaluated using the area under the receiver operating characteristic curve (AUROC) and compared with the FAST score using the DeLong test. Separation metrics, including the complement of overlap coefficient, Bhattacharyya distance, Kullback-Leibler divergence, and silhouette score, were used to assess inter-group separability. <b>Results</b>: All QUS parameters were significantly elevated in NASH patients (<i>p</i> < 0.05). AUROC values for individual QUS features ranged from 0.82 to 0.91, with the weighted QUS parameter achieving 0.91. The FAST score had the highest AUROC (0.96), though differences with the weighted QUS and homodyned-K parameters were not statistically significant (<i>p</i> > 0.05). Separation metrics ranked the FAST score highest, closely followed by the weighted QUS parameter. <b>Conclusions</b>: QUS biomarkers can be repurposed for NASH detection, with the weighted QUS parameter offering diagnostic accuracy comparable to the FAST score and serving as a promising, blood-free alternative.