Comparative diagnostic performance of ultrasound-guided attenuation parameter versus B-mode scoring for hepatic...

Accurate non-invasive assessment of hepatic steatosis is essential in metabolic dysfunction-associated steatotic liver disease. This study aimed to compare the diagnostic performance of the ultrasound-guided attenuation parameter (UGAP) and Hamaguchi score (HS) using ordinal-scale-specific statistical methods, with magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) as the reference standard.

This multicenter cross-sectional study enrolled 1,010 patients with chronic liver disease at six tertiary hepatology centers. UGAP and HS were compared against MRI-PDFF-defined steatosis grades (S0: < 5.2%, S1: 5.2- < 11.3%, S2: 11.3- < 17.1%, S3: ≥ 17.1%). Beyond conventional receiver operating characteristic (ROC) curve analysis, we applied the Adjusted Youden Index (AYI) for optimal cutoff determination across all ordinal categories and the Obuchowski measure (OM) for overall diagnostic accuracy assessment, incorporating penalties proportional to the magnitude of misclassification.

UGAP demonstrated stronger correlation with MRI-PDFF than HS (Spearman's rank correlation coefficient ρ = 0.805 vs. 0.776, p < 0.001). ROC analysis demonstrated higher areas under the curve for UGAP across all thresholds, with a significant difference at ≥ S2 (0.912 vs. 0.884, p = 0.002). The overall OM was significantly higher for UGAP (0.907, 95% confidence interval [CI] 0.894-0.919) than HS (0.886, 95% CI 0.872-0.899, p = 0.002). AYI-derived cutoffs for UGAP were 0.63, 0.71, and 0.81 dB/cm/MHz for S1, S2, and S3, respectively.

Ordinal-scale-specific methods demonstrate that UGAP provides superior diagnostic performance over conventional B-mode scoring, better reflecting graduated disease severity and the clinical consequences of misclassification. (University Hospital Medical Information Network000041196).