Diagnostic performance of a novel ultrasound-based quantitative method to assess liver steatosis in histologically identified nonalcoholic fatty liver disease

Aims: To investigate the diagnostic performance of ultrasound-guided attenuation parameter (UGAP) for the detection of hepatic steatosis in nonalcoholic fatty liver disease (NAFLD) cohorts using histopathology as the reference standard and comparing it with that of various imaging modalities. Materials and methods: A total of 87 subjects who underwent UGAP, controlled attenuation parameter (CAP), and magnetic resonance imaging-based proton density fat fraction (MRI-PDFF) between December, 2020 and January, 2022 were enrolled. Of these patients, 38 patients had NAFLD. The association between UGAP and clinical and imaging parameters was assessed using Pearson's or Spearman's correlations. The area under the receiver operating characteristic curve (AUROC) was used to evaluate the diagnostic performance. Results: The UGAP and MRI-logPDFF demonstrated strong positive correlations (correlation coefficient= 0.704, P <0.0001). UGAP showed excellent diagnostic performance for distinguishing steatosis grade >1 with an AUROC of 0.821 (95% confidence interval [CI], 0.729- 0.913), which was comparable to that of MRI-PDFF (0.829, 95%CI, 0.723-0.936). The AUROCs of BUSG (B-mode ultrasonography) (0.766, 95% CI, 0.767-0.856) and CAP (0.788, 95% CI, 0.684-0.891) were slightly lower than those of UGAP. The AUROCs of UGAP, MRI-PDFF, CAP, and BUSG for detecting steatosis grade >2 were 0.796 (95% CI, 0.616-0.975), 0.971 (95% CI, 0.936-1.000), 0.726 (95% CI, 0.561-0.891) and 0.774 (95% CI, 0.612-0.936), respectively. Conclusion: UGAP may be a valuable potential screening tool as a first-line assessment of liver steatosis in patients with NAFLD.