Preliminary study on determining the optimal position of region of interest for evaluating hepatic steatosis using ultrasound Attenuation imaging.

Abstract

Purpose: To find the optimal position of region of interest (ROI) for evaluating hepatic steatosis using attenuation imaging (ATI) in patients with metabolic dysfunction-associated fatty liver disease (MAFLD).

Methods: We retrospectively enrolled 143 consecutive patients who underwent percutaneous liver biopsy for the evaluation of MAFLD between October 2020 and October 2022. All ATI measurements were performed by the same radiologist. The ATI-ROI was placed at four different positions using a specialized workstation: the top edge of the sampling box (P1), the lower edge of the dark orange region (P2), 0.5 cm and 1 cm below the lower edge of the dark orange region (P3 and P4). Multivariate linear regression analysis and the area under the curve (AUC) analysis were performed.

Results: The AUCs of ATI at the four different ATI-ROI positions were 0.472 (95% confidence interval [CI]: 0.362-0.581), 0.693(0.611-0.768), 0.757(0.611-0.768), and 0.809 (0.735-0.870) for ≥ S1; 0.544 (0.459-0.628), 0.779 (0.702-0.844), 0.842 (0.772-0.898), and 0.865 (0.798-0.916) for ≥ S2; and 0.655 (0.571-0.733), 0.904 (0.843-0.947), 0.95 (0.9-0.979), and 0.949 (0.9-0.979) for S3, respectively. The factor that most significantly affected ATI was steatosis grade(P<0.001), when ATI-ROI was placed at the position of P2, P3, and P4.

Conclusion: Hepatic steatosis grade was the most significant determinant factor for ATI value at multivariate analysis. When clinicians conduct ATI measurement, the dark orange region indicating the area of reverberation artifact should be avoided, and placing the ATI-ROI 1 cm below the lower edge of the dark orange region may be a better choice.