Ultrasonography.  2020 Apr;39(2):121-129. 10.14366/usg.19034.

Reproducibility of ultrasound attenuation imaging for the noninvasive evaluation of hepatic steatosis

• Yoo J
• Lee JM
• Joo I
• Lee DH
• Yoon JH
• Kang HJ
• Ahn SJ

• KMID: 2501439
• DOI: http://doi.org/10.14366/usg.19034

Abstract

Purpose
The purpose of this study was to evaluate the intra-observer reproducibility of ultrasound attenuation imaging (ATI) for the noninvasive assessment of hepatic steatosis in patients with suspected hepatic steatosis and the inter-observer reproducibility in asymptomatic volunteers.
Methods
This prospective study was approved by our institutional review board and informed consent was obtained from all patients. In group 1, composed of patients with suspected hepatic steatosis (n=143), one abdominal radiologist performed gray-scale ultrasonography and two sessions of ATI. In group 2, composed of healthy volunteers (n=18), three independent sessions of ATI were performed by three abdominal radiologists. The visual degree of hepatic steatosis in all study subjects was graded on a 4-point scale by two independent reviewers using gray-scale ultrasonography. Thereafter, the attenuation coefficient (AC) was correlated with the degree of hepatic steatosis using Spearman rank correlation analysis. Intra-class correlation coefficients (ICCs) were used to assess the intra-observer (group 1) and inter-observer reproducibility (group 2) of ATI measurements.
Results
For the intra-observer reproducibility of ATI, the ICC was 0.929 (95% confidence interval [CI], 0.901 to 0.949), and the coefficient of variation was 7.1%. Inter-observer reproducibility of ATI measurements showed an ICC of 0.792 (95% CI, 0.549 to 0.916). The AC showed a significant correlation with the visual grade of hepatic steatosis for both reviewers (rho, 0.780 and 0.695; P<0.001, respectively).
Conclusion
ATI showed high intra- and inter-observer reproducibility in the assessment of hepatic steatosis.

Keyword

Ultrasonography; Non-alcoholic fatty liver disease; Obesity