The diagnostic value of novel ultrasound attenuation analysis in detecting liver steatosis identified by the controlled attenuation parameter: a diagnostic accuracy study

BACKGROUND: Ultrasound attenuation analysis (USAT) is a type of novel ultrasound attenuation imaging that can be used to detect hepatic steatosis based on the attenuation coefficient. We sought to evaluate the diagnostic accuracy for assessing the severity of liver steatosis by USAT using the controlled attenuation parameter (CAP) as a reference in patients with non-alcoholic fatty liver diseases (NAFLD) and chronic hepatitis B (CHB) infections. METHODS: In total, 326 consecutive subjects with or without chronic liver diseases were enrolled in this study who underwent CAP examination and USAT to evaluate hepatic steatosis from October 2022 to November 2022 at The Fourth Affiliated Hospital of Zhejiang University School of Medicine. Hepatic steatosis stage (S) was determined by CAP according to the following cut-off values recommended by the manufacturer: S ≥ S1 (≥11%, mild): 238 dB/m; S ≥ S2 (≥34%, moderate): 259 dB/m; and S ≥ S3 (≥67%, severe): 292 dB/m, and thus the optimal cut-off values for the USAT were acquired. The area under the receiver operating characteristic curves (AUROCs) for the categories of steatosis were used to measure the diagnostic accuracy of USAT. RESULTS: A total of 296 patients were recruited, including 101 (34.1%) patients with NAFLD, 172 (58.1%) with CHB and the remainder were healthy control subjects (7.8%). We used the CAP as the reference standard and found that the USAT increased gradually as the stage of steatosis increased (P<0.001). A strong positive correlation was found between USAT and CAP (r=0.787, P<0.001). In the whole population, the AUROCs of the USAT for S ≥ S1, S ≥ S2 and S ≥ 3 were 0.89, 0.90, and 0.90, respectively, and the cut-off values according to the Youden index for S ≥ S1, S ≥ S2, and S ≥ 3 were 0.62, 0.66, and 0.72 dB/cm/MHz, respectively. Our study showed that the USAT had a good ability to detect hepatic steatosis in NAFLD and CHB patients. CONCLUSIONS: USAT had a strong association with CAP and a good diagnostic capability in the detection of hepatic steatosis, which appears to be a promising tool for the non-invasive detection and quantification of hepatic steatosis.