Noninvasive Quantification of Hepatic Steatosis Using Ultrasound-Derived Fat Fraction (CHESS2303): A Prospective Multicenter Study

Abstract

Ultrasound-derived fat fraction (UDFF) is designed to assess the hepatic fat content quantitatively. A multicenter study that verifies the diagnostic performance of UDFF for detecting hepatic steatosis has not yet been reported. This study aimed to evaluate the performance of UDFF for diagnosing and grading hepatic steatosis. Participants referred for assessment of hepatic steatosis were prospectively recruited from eight hospitals. All participants underwent UDFF and magnetic resonance imaging proton density fat fraction (MRI-PDFF) examinations. MRI-PDFF was used as the reference for diagnosing hepatic steatosis. From January 2023 to July 2023, a total of 300 participants were included. The median body mass index was 25.4 kg/m² (interquartile range: 22.7-28.1). UDFF values were positively correlated with MRI-PDFF (R = 0.80, p < 0.001). Using MRI-PDFF ≥ 5%, ≥ 15%, and ≥ 25% as the reference standard for detecting mild, moderate, and severe hepatic steatosis, the best cutoff values of UDFF were 7.6% (area under the receiver operating characteristic curves [AUC] = 0.90), 15.9% (AUC = 0.90), and 22.3% (AUC = 0.91), respectively. Thus, UDFF has excellent diagnostic performance in detecting and grading hepatic steatosis.

Keywords: hepatic steatosis; magnetic resonance imaging proton density fat fraction (MRI‐PDFF); noninvasive; quantification; ultrasound‐derived fat fraction (UDFF).

FIGURE 1

The flow diagram of the study cohort. UDFF, ultrasound‐derived fat fraction; MRI‐PDFF, magnetic resonance imaging proton density fat fraction.

FIGURE 2

The correlation between ultrasound‐derived fat fraction (UDFF) and magnetic resonance imaging proton density fat fraction (MRI‐PDFF). (A) Bland–Altman plot shows that the mean difference in the liver fat content measured by UDFF and MRI‐PDFF is 2.36 (red dashed line), and the upper and lower 95% limits of agreement were 13.82 and −9.08, respectively (black dashed lines). (B) Scatterplots of UDFF versus MRI‐PDFF. UDFF was positively correlated with MRI‐PDFF, with a correlation coefficient of 0.80 (95% confidence interval: 0.75 to 0.84, p < 0.001).

FIGURE 3

Representative images. (A) A 41‐year‐old female with a body mass index of 29.04 kg/m² and an ultrasound‐derived fat fraction (UDFF) image displayed a value of 18%. (B) The magnetic resonance imaging proton density fat fraction (MRI‐PDFF) image showed a value of 14.8%. (C) A 45‐year‐old female with a body mass index of 24.74 kg/m² and a UDFF image displayed a value of 5%. (D) The MRI‐PDFF image showed a value of 4.3%.

FIGURE 4

The area under the receiver operating characteristic curves (AUCs) of ultrasound‐derived fat fraction (UDFF) to diagnose hepatic steatosis in the training set. (A) Using magnetic resonance imaging proton density fat fraction (MRI‐PDFF) ≥ 5%, ≥ 15%, and ≥ 25% as the reference to detect mild, moderate, and severe hepatic steatosis, the AUCs of UDFF (cutoff values ≥ 7.6%, ≥ 15.9%, and ≥ 22.3%) were 0.90, 0.90, and 0.91, respectively. (B) Using the same threshold values as MRI‐PDFF, the AUCs of UDFF (cutoff values ≥ 5%, ≥ 15%, and ≥ 25%) for detecting mild, moderate, and severe hepatic steatosis were 0.77, 0.82, and 0.74, respectively.

FIGURE 5

The determinant factors for ultrasound‐derived fat fraction (UDFF) value in the training set. The univariate and multivariate analysis presents odds ratios (ORs) and 95% confidence intervals (CIs) to show the determinant factors for the UDFF values of participants. T2DM, type 2 diabetes mellitus; BMI, body mass index; TC, total cholesterol; TG, triglycerides; HDL‐C, high‐density lipoprotein cholesterol; LDL‐C, low‐density lipoprotein cholesterol; ALT, alanine aminotransferase; AST, aspartate aminotransferase; GGT, gamma‐glutamyl transferase; FPG, fasting plasma glucose; HbA1c, hemoglobin A1c; BMUS, B mode ultrasound.