Comparative Study Of The Accuracy Of~1H-MRS,in-phase And Oppose-phase Of MRI And CT In Quantifying Hepatic Steatosis

Purpose:The objective of this study is to compare the accuracy of proton magnetic resonance spectroscopy (1H-MRS), in-phase and oppose-phase of magnetic resonance imaging(dual gradient echo, DGE-MRI) and computed tomography(CT) for the diagnosis and quantitative estimation of hepatic steatosis(HS), using the histopathologic degree of hepatic steatosis(HS) as the gold standard.Materials and methods:A total of52patients underwent1H-MRS, DGE-MRI, CT, and liver biopsy one or two days later. Using the histopathology as the gold reference, the sensitivity and specificity of1H-MRS(liver-water ratio, LWR), DGE-MRI(hepatic fat fraction, HFF) and CT (liver-spleen ratio, LSR) for diagnosing5%≤HS≤30%and HS>30%were compared by receiver operating characteristic (ROC) analysis. The accuracy of H-MRS, DGE-MRI, and CT in quantitative estimation of HS was analyzed by comparing the Kappa(K)values. The correlation between H-MRS, DGE-MRI, CT and histopathology was analyzed by Spearman rank correlation analysis.Result:1. In all52patients, the cases of F0(absence of adipose degeneration), F1(hepatocyte adipose degeneration), F2(mild fatty liver), F3(middle fatty liver) and F4(severe fatty liver) were19,11,12,6and4, respectively. Inter-comparison among different histopathological degree showed following findings:the values of LWR, HFF and LSR had statistical significance(F values were 68.006,32.025,35.343, respectively, P<0.05). With the rise of pathological degree, the values of LWR and HFF were corresponding increase, whereas the values of LSR were decrease accordingly.2. For LWR, there were statistical significance among each pathological degree. The HFF of F2was statistical significance with that of F0, and the F3was statistical significance with the F0, F1and F2. The LSR of F3and F4were statistical significance with F0, F1, F2respectively.3. The threshold values of’H-MRS, DGE-MRI and CT in diagnosing5%≤HS≤30%were1.537%,14.009%and1.297, respectively, and the corresponding Youden index were0.727,0.490and0.368, respectively.The’H-MRS had the best consistency, the Kappa value(0.772) was significantly higher than the DGE-MRI and CT(0.534,0.300).4. The threshold values of’H-MRS and DGE-MRI in diagnosing HS>30%were3.11%and15.18%, respectively, the corresponding Youden index were0.809and0.764, respectively. Both Kappa values (0、804,0.764) were exceeded0.70for the’H-MRS and DGE-MRI.5. The degree of hepatic steatosis determined by1H-MRS, DGE-MRI and CT was correlated with histopathology, and the highest correlated coefficient was0.890(1H-MRS to the histopathology).Conclusion:Among’H-MRS, DGE-MRI and CT,’H-MRS is the most accurate method for the diagnosis and quantitative estimation of HS. Therefore,1H-MRS may be the most optimum imaging examination for the non-invasive assessment of HS. It has the potential to replace invasive liver biopsy.