Aims
To evaluate and validate a simple quantitative ultrasound (US) for determined the hepatic fat content (HFC) based on a combination of the US hepatic/renal ratio (US-HRR) and UShepatic echo-intensity attenuation rate (US-HAR)
Method
There were a total of 242 subjects recruited in the present study. All subjects were examined for HFC by quantitative US and [1H]-magnetic resonance spectroscopy (1H-MRS). The US-HRR and US-HAR were acquired from ordinary ultrasound images of liver and kidney using the Image J software.
Results
The results found that US-HRR and US-HAR correlated with 1H-MRS HFC (US-HRR: r = 0.946, P< 0.001; US-HAR: r = 0.936, P< 0.001). The equation for HFC prediction by using quantitative US was: HFC (%) = 28.965 × US-HRR + 218.045 × US-HAR -8.892.Subgroup analysis in study subjects with body mass index (BMI) ≥ 28 showed that quantitative US HFC was associated with 1H-MRS HFC (R2 = 0.953, P< 0.001). Receiver operating characteristic (ROC) analysis observed that the cut-off value of fatty liver diagnosis was 6.71% in using quantitative USmodel; with the sensitivity and specificity for fatty liver diagnosis were 94.15% and 96.30%, respectively.Furthermore, variability analysis indicated that there were relative high degrees of consistencies between different operators or ultrasonic apparatus in the measurement of HFC.
Conclusion
Overall, our study established and confirmed the application of quantitativeUS model for relatively accurate estimation of HFC through combination of US-HRR and US-HAR, and the variability analysis revealed a good repeatability, suggesting that US is capable to be a valid alternative to 1H-MRS as a non-invasive, simple, low costs and clinical practical option in assessment of liver fat.

Quantitative ultrasound of hepatic/renal ratio and hepatic echo-intensity attenuation rate in assessment of HFC