Reproducibility of ultrasound-guided attenuation parameter (UGAP) to the noninvasive evaluation of hepatic steatosis

Abstract

The aim of this study was to identify the applicability of an ultrasound-guided attenuation parameter (UGAP) for the noninvasive assessment of hepatic steatosis in clinical practice and to compare its correlation with B-mode ultrasound (US). From May to July 2021, 63 subjects with different body mass index (BMI) grades were included in the prospective study. All of them performed UGAP measurements, under different breathing manipulations, positions, diet statuses, and operators. After that, the UGAP values were compared with the visual grades of hepatic steatosis on B-mode US using a 4-point scale method. The intraclass correlation (ICC) of the UGAP values between the two radiologists was 0.862 (p < 0.001), and the ICCs of the UGAP values on the same day and different days by radiologist A were 0.899 (p < 0.001) and 0.910 (p < 0.001), respectively. There were no significant differences in UGAP values under different breathing manipulations (p > 0.05), positions (p > 0.05), or diet statuses (p = 0.300). The UGAP values in the fasting (supine position, segment V, 1) condition among the lean (BMI < 24 kg/m2), overweight (24 kg/m2 ≤ BMI < 28 kg/m2) and obese groups (BMI ≥ 28 kg/m2) were 0.60 ± 0.12, 0.66 ± 0.14, and 0.71 ± 0.11 dB/cm/MHz, respectively, with a significant difference (p = 0.006). The correlation coefficients (Rho) between the UGAP values and the visual grades of hepatic steatosis by the two reviewers were 0.845 (p < 0.001) and 0.850 (p < 0.001), corresponding to a strong relationship. Steatosis grades by reviewer 1 (p = 0.036) and reviewer 2 (p = 0.003) were significant factors determining the UGAP values according to the multivariate linear regression analysis. UGAP demonstrated excellent intraobserver and interobserver reproducibility in the assessment of hepatic steatosis. UGAP may be a promising tool in clinical practice to predict hepatic steatosis.

Interobserver Variability in Ultrasound‐Based Liver Fat Quantification

“…In our study, we found that TAI and TSI measurements demonstrate strong correlation with visual hepatic steatosis grades and there was a significant difference in TAI and TSI measurements across different visual hepatic steatosis grades. These findings were consistent with previous studies reported that various ultrasound‐based techniques used to quantify liver fat content are correlated with visual hepatosteatosis grades and have significant differences according to visual hepatosteatosis grades 17–19 . Therefore, our study supports the clinical applicability of QUS techniques for the diagnosis of hepatosteatosis.…”

“…Strauss et al 12 reported that visual assessment of hepatosteatosis on ultrasonography has substantial observer variability. However, recent studies that were designed to assess reproducibility of various QUS techniques reported high agreement levels for visual hepatic steatosis grades and our results were in line with these studies 17,18 …”

“…These findings were consistent with previous studies reported that various ultrasound-based techniques used to quantify liver fat content are correlated with visual hepatosteatosis grades and have significant differences according to visual hepatosteatosis grades. [17][18][19] Therefore, our study supports the clinical applicability of QUS techniques for the diagnosis of hepatosteatosis. However, future studies that assess the diagnostic performance of QUS techniques using MRI PDFF or liver biopsy as reference standard and correlation analyses between QUS measurements and reference standard techniques will be more valuable.…”

How many times should we repeat measurements of the ultrasound-guided attenuation parameter for evaluating hepatic steatosis?

“…Thus, further studies comparing many repetition protocols using several ultrasound attenuation platforms are needed. Finally, UGAP measurements were made by only one radiologist, although previous studies have demonstrated high intraobserver and interobserver reproducibility [ 35 , 36 ]. Additionally, the second set of six measurements might have been influenced by the first set of six measurements because all measurements were continuously performed by the same observer; however, this study focused on the preceding six measurements, which were not affected by the following six measurements.…”

Once-Weekly Subcutaneous Semaglutide Improves Fatty Liver Disease in Patients with Type 2 Diabetes: A 52-Week Prospective Real-Life Study

“…Based upon the latter point, minor steatosis or small changes over time in hepatic fat deposits would preferably be studied with the Controlled Attenuation Parameter (CAP) algorithm implemented in the transient elastography (FibroScan) system, and the Ultrasound-Guided Attenuation Parameter (UGAP). These imaging techniques are an accurate diagnostic tool for the point-of-care investigation of MAFLD [ 46 ], but they are not commonly available in internal medicine clinics.…”