Performance of the Attenuation Imaging Technology in the Detection of Liver Steatosis.

Objectives: The main aim was to assess the performance and cutoff value for the detection of liver steatosis (grade S > 0) with the Attenuation Imaging-Penetration (ATI-Pen) algorithm available on the Aplio i-series ultrasound systems (Canon Medical Systems, Otawara, Japan). The magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) was used as the reference standard. Secondary aims were to compare the results to those obtained with the previous ATI algorithm (Attenuation Imaging-General [ATI-Gen]) and with the controlled attenuation parameter (CAP) and to generate a regression equation between ATI-Pen and ATI-Gen values.

Methods: Consecutive adult patients potentially at risk of liver steatosis were prospectively enrolled. Each patient underwent ultrasound quantification of liver steatosis with ATI-Pen and ATI-Gen and a CAP assessment with the FibroScan system (Echosens, Paris, France). The MRI-PDFF evaluation was performed within a week. The correlations between ATI-Pen, ATI-Gen, the CAP, and the MRI-PDFF were analyzed with the Pearson rank correlation coefficient. The diagnostic performance of ATI-Pen, ATI-Gen, and the CAP was assessed with receiver operating characteristic curves and an area under the receiver operating characteristic curve (AUROC) analysis.

Results: Seventy-two individuals (31 male and 41 female) were enrolled. Correlation coefficients of ATI-Pen, ATI-Gen, and the CAP with the MRI-PDFF were 0.78, 0.83, and 0.58, respectively. The AUROCs of ATI-Pen, ATI-Gen, and the CAP for detecting steatosis (S > 0) were 0.90 (95% confidence interval, 0.81-0.96), 0.92 (0.82-0.98), and 0.85 (0.74-0.92), and the cutoffs were greater than 0.69 dB/cm/MHz, greater than 0.62 dB/cm/MHz, and greater than 273 dB/m. The regression equation between ATI-Pen and ATI-Gen was ATI-Pen = 0.88 ATI-Gen + 0.13.

Conclusions: Attenuation Imaging is a reliable tool for detecting liver steatosis, showing an excellent correlation with the MRI-PDFF and high performance with AUROCs of 0.90 or higher.