title: Ultrasound hepatic/renal ratio and hepatic attenuation rate for quantifying liver fat content.
abstract: OBJECTIVE
  To establish and validate a simple quantitative assessment method for nonalcoholic fatty liver disease (NAFLD) based on a combination of the ultrasound hepatic/renal ratio and hepatic attenuation rate.
  
  
  METHODS
  A total of 170 subjects were enrolled in this study. All subjects were examined by ultrasound and (1)H-magnetic resonance spectroscopy ((1)H-MRS) on the same day. The ultrasound hepatic/renal echo-intensity ratio and ultrasound hepatic echo-intensity attenuation rate were obtained from ordinary ultrasound images using the MATLAB program.
  
  
  RESULTS
  Correlation analysis revealed that the ultrasound hepatic/renal ratio and hepatic echo-intensity attenuation rate were significantly correlated with (1)H-MRS liver fat content (ultrasound hepatic/renal ratio: r = 0.952, P = 0.000; hepatic echo-intensity attenuation r = 0.850, P = 0.000). The equation for predicting liver fat content by ultrasound (quantitative ultrasound model) is: liver fat content (%) = 61.519 × ultrasound hepatic/renal ratio + 167.701 × hepatic echo-intensity attenuation rate -26.736. Spearman correlation analysis revealed that the liver fat content ratio of the quantitative ultrasound model was positively correlated with serum alanine aminotransferase, aspartate aminotransferase, and triglyceride, but negatively correlated with high density lipoprotein cholesterol. Receiver operating characteristic curve analysis revealed that the optimal point for diagnosing fatty liver was 9.15% in the quantitative ultrasound model. Furthermore, in the quantitative ultrasound model, fatty liver diagnostic sensitivity and specificity were 94.7% and 100.0%, respectively, showing that the quantitative ultrasound model was better than conventional ultrasound methods or the combined ultrasound hepatic/renal ratio and hepatic echo-intensity attenuation rate. If the (1)H-MRS liver fat content had a value < 15%, the sensitivity and specificity of the ultrasound quantitative model would be 81.4% and 100%, which still shows that using the model is better than the other methods.
  
  
  CONCLUSIONS
  The quantitative ultrasound model is a simple, low-cost, and sensitive tool that can accurately assess hepatic fat content in clinical practice. It provides an easy and effective parameter for the early diagnosis of mild hepatic steatosis and evaluation of the efficacy of NAFLD treatment.
authors.affiliation: Bo Zhang, Fang Ding, Tian Chen, Liang-Hua Xia, Juan Qian, Department of echocardiography, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Bo Zhang, Fang Ding, Tian Chen, Liang-Hua Xia, Juan Qian, Department of echocardiography, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Ding
authors.affiliation: Bo Zhang, Fang Ding, Tian Chen, Liang-Hua Xia, Juan Qian, Department of echocardiography, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Chen
authors.affiliation: Bo Zhang, Fang Ding, Tian Chen, Liang-Hua Xia, Juan Qian, Department of echocardiography, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
authors.forename: Liang-Hua
authors.initials: LH
authors.lastname: Xia
authors.affiliation: Bo Zhang, Fang Ding, Tian Chen, Liang-Hua Xia, Juan Qian, Department of echocardiography, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Qian
authors.affiliation: Bo Zhang, Fang Ding, Tian Chen, Liang-Hua Xia, Juan Qian, Department of echocardiography, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
authors.forename: Guo-Yi
authors.initials: GY
authors.lastname: Lv
mesh_terms: D050154:Adiposity; D000328:Adult; D019540:Area Under Curve; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008099:Liver / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011379:Prognosis; D066244:Proton Magnetic Resonance Spectroscopy; D012372:ROC Curve; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014463:Ultrasonography
keywords: Non-alcoholic fatty liver disease; Ultrasound hepatic echo-intensity attenuation rate; Ultrasound hepatic/renal ratio