Ultrasound assessment using Attenuation Imaging (ATI) with liver biopsy correlation

Introduction: Hepatic steatosis duration and severity are risk factors for liver fibrosis and cardiometabolic disease. We assessed the diagnostic accuracy of attenuation imaging (ATI), compared with histologic hepatosteatosis grading in adults with varied suspected liver pathologies.

Methods: Liver biopsy was performed on 76 patients (51 women, 25 men) with non-malignant diffuse parenchymal liver disease, within 4 weeks of multiparametric liver ultrasound including attenuation imaging (ATI). Skin-liver capsule distance (SCD) and body mass index (BMI) were measured. Histologic steatosis was graded none (S0), mild (S1), moderate (S2) or severe (S3). We compared histology and sonographic parameters.

Results: The median patient age was 50.5 (range 18-83) years and BMI 28.9 kg/m2 (interquartile range 24.0-33.3). The distribution of histologic steatosis grade was S0 (44%), S1(17%), S2(30%) and S3(9%). Median ATI value for each biopsy steatosis grade was 0.60 (IQR 0.52-0.65), 0.65 (IQR 0.6-0.71), 0.83 (IQR 0.74-0.90) and 0.90 (IQR 0.82-1.01) dB/cm/MHz for S0, S1, S2 and S3 respectively. The AUC of ATI for detection of any steatosis (S1-S3) and moderate to severe steatosis (S2-S3) was 0.85 (95% CI, 0.75-0.91) and 0.91 (95% CI, 0.83-0.99) with cutoffs of 0.55 and 0.62 dB/cm/MHz. ATI threshold of 0.74dB/cm/MHz was able to discriminate between S0-S1 and S2-3 with accuracy, CI and kappa statistic of 0.8889, 0.65-0.98 and 0.7534.

Conclusion: We found good correlation between ATI and steatosis grade. The most accurate discrimination was between none to mild (S0-1) and moderate to severe (S2-3) steatosis.