Masahito Shimizu

Aim This study aimed to evaluate the diagnostic performance of attenuation measurement (ATT; dual‐frequency method) and improved algorithm of ATT (iATT; reference method) for the assessment of hepatic steatosis using magnetic resonance imaging (MRI)‐derived proton density fat fraction (PDFF) as the reference standard. Methods We prospectively analyzed 427 patients with chronic liver disease who underwent ATT, iATT, or MRI‐derived PDFF. Correlation coefficients were analyzed, and diagnostic values were evaluated by area under the receiver operating characteristic curve (AUROC). The steatosis grade was categorized as S0 (<5.2%), S1 (≥5.2%, <11.3%), S2 (≥11.3%, <17.1%), and S3 (≥17.1%) according to MRI‐derived PDFF values. Results The median ATT and iATT values were 0.61 dB/cm/MHz (interquartile range 0.55–0.67 dB/cm/MHz) and 0.66 dB/cm/MHz (interquartile range 0.57–0.77 dB/cm/MHz). ATT and iATT values increased significantly as the steatosis grade increased in the order S0, S1, S2, and S3 ( p < 0.001). The correlation coefficients between ATT or iATT values and MRI‐derived PDFF values were 0.533 (95% confidence interval [CI] 0.477–0.610) and 0.803 (95% CI 0.766–0.834), with a significant difference between them ( p < 0.001). For the detection of hepatic steatosis of ≥S1, ≥S2, and ≥S3, iATT yielded AUROCs of 0.926 (95% CI 0.901–0.951), 0.913 (95% CI 0.885–0.941), and 0.902 (95% CI 0.869–0.935), with significantly higher AUROC values than for ATT ( p < 0.001, p < 0.001, p = 0.001). Conclusion iATT showed excellent diagnostic performance for hepatic steatosis, and was strongly correlated with MRI‐derived PDFF, with AUROCs of ≥0.900.