Clinical Trials Study
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World J Gastroenterol. Dec 21, 2014; 20(47): 17985-17992
Published online Dec 21, 2014. doi: 10.3748/wjg.v20.i47.17985
Ultrasound hepatic/renal ratio and hepatic attenuation rate for quantifying liver fat content
Bo Zhang, Fang Ding, Tian Chen, Liang-Hua Xia, Juan Qian, Guo-Yi Lv
Bo Zhang, Fang Ding, Tian Chen, Liang-Hua Xia, Juan Qian, Department of echocardiography, East Hospital, Tongji University School of Medicine, Shanghai 200120, China
Guo-Yi Lv, Department of Radiology, Huazhong University of Science and Technology, Tongji Medical College, Pu Ai Hospital, Wuhan 430030, Hubei Province, China
Author contributions: Zhang B and Lv GY designed the study and wrote the manuscript; Ding F, Chen T and Xia LH performed the majority of the experiments; Qian J provided vital analytical tools and was also involved in editing the manuscript.
Correspondence to: Guo-Yi Lv, MD, Deputy Chief of Physicians, Department of Radiology, Huazhong University of Science and Technology, Tongji Medical College, Pu Ai Hospital, No. 473 Hanzheng Road, Qiaokou District, Wuhan 430030, Hubei Province, China. laodongdong999@sina.com
Telephone: +86-27-68834835 Fax: +86-27-68834835
Received: May 24, 2014
Revised: August 24, 2014
Accepted: September 29, 2014
Published online: December 21, 2014
Abstract

AIM: 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 1H-magnetic resonance spectroscopy (1H-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 1H-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 1H-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.

CONCLUSION: 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.

Keywords: Non-alcoholic fatty liver disease, Ultrasound hepatic/renal ratio, Ultrasound hepatic echo-intensity attenuation rate

Core tip: 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 early diagnosis of mild hepatic steatosis and evaluation of the efficacy of non-alcoholic fatty liver disease treatment.