Cross-sectional investigation of correlation between hepatic steatosis and IVIM perfusion on MR imaging.

The purpose of this study was to investigate the relationship between liver fat fraction (FF) and diffusion parameters derived from the intravoxel incoherent motion (IVIM) model. Thirty-six subjects with suspected nonalcoholic fatty liver disease underwent diffusion-weighted magnetic resonance imaging with 10 b-values and spoiled gradient recalled echo imaging with six echoes for fat quantification. Correlations were measured between FF, transverse relaxivity (R2), diffusivity (D) and perfusion fraction (f). The primary finding was that no significant correlation was obtained for D vs. FF or f vs. FF. Significant correlations were obtained for D vs. R2 (r=-0.490, P=.002) and f vs. D (r=-0.458, P=.005). The conclusion is that hepatic steatosis does not affect measurement of perfusion or diffusion and therefore is unlikely to confound the use of apparent diffusivity to evaluate hepatic fibrosis.