Quantitative assessment of hepatic steatosis by ultrasound-guided attenuation parameter in patients with impaired glucose tolerance

OBJECTIVES: Our objective was to provide further evidence regarding the diagnostic accuracy of ultrasound-guided attenuation parameter (UGAP) for detecting hepatic steatosis in a selected and homogeneous cohort of patients with impaired glucose tolerance using magnetic resonance imaging-proton density fat fraction (MRI-PDFF) as the standard reference method. MATERIALS AND METHODS: From October 2023 to March 2024, individuals with impaired glucose tolerance and suspected metabolic dysfunction-associated steatotic liver disease (MASLD) who underwent abdominal ultrasound and MRI-PDFF were enrolled in this prospective study. Multivariable linear regression was performed to assess independent factors associated with UGAP. The correlation between UGAP, and MRI-PDFF was evaluated using the Pearson correlation coefficient. The diagnostic performance of the UGAP for hepatic steatosis was assessed using the area under the receiver operating characteristic curve (AUC). RESULTS: A total of 193 participants (median age, 35 years; IQR, 25-48 years; 98 male) were evaluated, including 90 participants (47%) with MASLD. Body mass index (BMI), waist circumference, and skin-liver capsule distance were independently associated with UGAP. UGAP was strongly and positively correlated with MRI-PDFF (r = 0.890, p < 0.001). The AUCs of UGAP for diagnosing hepatic steatosis ≥ S1 (MRI-PDFF ≥ 6.4%), ≥ S2 (MRI-PDFF ≥ 17.4%), and ≥ S3 (MRI-PDFF ≥ 22.1%) were 0.980 (95% CI: 0.957-1.000), 0.955 (95% CI: 0.912-0.999), and 0.985 (95% CI: 0.970-1.000), respectively. CONCLUSIONS: UGAP could accurately diagnose hepatic steatosis and estimate the hepatic fat fraction. CRITICAL RELEVANCE STATEMENT: UGAP has high diagnostic performance for hepatic steatosis. UGAP offers a method of quantifying liver fat content similar to MRI-PDFF, which is anticipated to be beneficial in the long-term monitoring of patients with impaired glucose tolerance. KEY POINTS: Hepatic steatosis is an early factor that causes liver damage in MASLD. UGAP has an accurate diagnostic performance for hepatic steatosis. UGAP was positively correlated with MRI- proton density fat fraction. Some clinical parameters may affect UGAP measurement.