Ultrasound Quantitative Evaluation of Hepatic Fat Content: Comparison with 1H Magnetic Resonance Spectroscopy

  • Marcello Mancini, Biostructure and Bioimaging Institute, National Council of Research, Naples, Italy
  • Anna Prinster, Biostructure and Bioimaging Institute, National Council of Research, Naples, Italy
  • Raffaele Liuzzi, Biostructure and Bioimaging Institute, National Council of Research, Naples, Italy
  • Gianni Annuzzi, Department of Clinical and Experimental Medicine. University Federico II , Naples, Italy
  • Rosalba Giacco, Institute of Food Science, National Council of Research, Avellino, Italy
  • Carmela Medagli, Department of Radiology, University Federico II, Via Pansini 5, Naples, Italy
  • Angela Albarosa Rivellese, Department of Clinical and Experimental Medicine. University Federico II , Naples, Italy
  • Marco Salvatore, Department of Radiology, University Federico II, Via Pansini 5, Naples, Italy

    • The aim of this study was to determine the diagnostic performance of Ultrasound (US) in the quantitative assessment of steatosis by comparison with Proton Magnetic Resonance Spectroscopy (1H-MRS) as a reference standard. Three liver echo intensity indices were derived: Ultrasound Hepatic Mean Gray level (HMG), Hepatic-to-Renal echo-intensity ratio (H/R), Hepatic-to-Portal blood echo-intensity ratio (H/P). The 1H-MRS degree of steatosis was determined as % fat by wet weight. Regression equations were used to quantitatively estimate the hepatic fat content. The hepatic fat content by 1H-MRS analysis ranged from 0.10% to 28.9% (median value 4.8%). US H/R was correlated to the degree of steatosis on 1H-MRS (R-square 0.92, p<0.0001) while no correlation was found between 1H-MRS hepatic fat content, HMG and H/P. A receiver operating characteristic curve identified the H/R of 2.2 as the best cut-off point for the prediction of 1H-MRS >5% yielding measures of sensitivity and specificity for 100% and 95% respectively. In this pilot study US H/R exhibit high sensitivity and specificity for detecting liver fatty changes. Our results indicate that quantitative evaluation of hepatic fat content can be performed using US H/R and could therefore prove a valuable analytic tool in the clinical investigation.