Evaluation of the optimal cutoff value of ultrasound attenuation imaging for the diagnosis of fatty liver in healthy young adults in their 20s

Abstract

Attenuation imaging (ATI) is an ultrasound-based technique for quantifying hepatic fat content. While optimal cutoff values have been proposed for middle-aged populations, their applicability to individuals in their twenties remains uncertain. To evaluate the diagnostic performance of ATI and determine an appropriate cutoff value for hepatic steatosis in healthy individuals in their twenties. We enrolled 230 healthy university students (mean age 20.0 years) who underwent abdominal ultrasound screening. Hepatic steatosis was diagnosed using B-mode ultrasound based on the Japanese Society of Ultrasonics in Medicine criteria: (1) increased liver echogenicity relative to the renal cortex, (2) blurring of intrahepatic vessels, or (3) increased posterior echo attenuation. ROC analysis was performed to determine the optimal ATI cutoff. Multivariate logistic regression was used to evaluate ATI as an independent predictor, adjusting for BMI, liver enzymes (ALT, AST, γ-GTP), alcohol intake, and exercise habits. The optimal ATI cutoff was 0.58 dB/cm/MHz, yielding a sensitivity of 75.0%, specificity of 100.0%, and AUC of 0.938. Multivariate analysis confirmed ATI as an independent predictor of hepatic steatosis (OR = 66.48, 95%CI: 30.99–101.97, p < 0.001), even in participants with normal BMI and liver function. ATI demonstrated high diagnostic accuracy for hepatic steatosis in individuals in their twenties. An age-specific lower cutoff value may enhance screening sensitivity. ATI offers a practical, non-invasive tool for early detection of hepatic steatosis in routine health assessments for this demographic.