Diffusion‐weighted MRI of fatty liver

Abstract

Purpose: To investigate the effect of fat infiltration on the apparent diffusion coefficient (ADC) of liver, and assess the relationship between ADC and hepatic fat fraction (HFF).Materials and Methods: MRI scans of 120 consecutive patients were included in this retrospective study. Of these, 42 patients were included in the fatty liver group and 78 in the control group. ADC values were measured from a pair of diffusion-weighted (DW) images (b ¼ 0 mm 2 /s and 1000 mm 2 /s). HFFs were measured using T1W GRE dual-echo images. The difference between the ADCs of the two groups was assessed with the t-test. The relationship between HFF and ADC was determined using linear regression analysis and the Pearson correlation coefficient (r).Results: Mean HFFs were 0.85 6 2.86 and 13.67 6 8.62 in the control and fatty liver groups, respectively. The mean ADC of fatty liver group 1.20 6 0.22 Â 10 À3 mm 2 /s was significantly lower than that of the control group 1.32 6 0.23 Â 10 À3 mm 2 /s (P ¼ 0.02). Linear regression analysis revealed an inverse relationship between ADC and HFF (r ¼ À0.39, P < 0.0001).Conclusion: ADC significantly decreases in patients with >5% HFF, and ADC and HFF exhibit an inverse relationship.

Does steatosis affect the performance of diffusion-weighted MRI values for fibrosis evaluation in patients with chronic hepatitis C genotype 4?

“…Our results demonstrated a significant decrease in the ADC value in the subgroups of patients with steatosis in both groups of patients with early and advanced fibrosis stages in comparison to that in patients without steatosis. Our results are in agreement with those reported by Poyraz et al (30), wherein it was reported that hepatic fat has an influence on the ADC value. The decrease in the ADC value observed in our study can be explained by hepatocyte swelling and the changes in the architectural structure of the liver that results from the accumulation of fat droplets in the liver cells (32).…”

Quantifying hepatic fibrosis using a biexponential model of diffusion weighted imaging in ex vivo liver specimens

“…In fact, a recent machine learning-based approach, combining MRI parameters derived from hepatic hemodynamic changes demonstrated strong correlations with hepatic fibrosis [38]. While the correlation of the combination of the biexponential model derived parameters and hepatic fibrosis did not exceed that achieved with the monoexponential model-derived diffusion coefficients, the multiple parameters derived with this approach may offer utility in mitigating confounding factors in deriving liver diffusion coefficients, such as the presence of hepatic steatosis, known to affect diffusion coefficients [39,40]. For instance, the presence of steatosis may preferentially affect one of the parameters obtained using a biexponential model.…”

Liver histology and diffusion‐weighted MRI in children with nonalcoholic fatty liver disease: A MAGNET study

“…One study in adults [18] and another in mice [19] found that ADC decreased with steatosis. Other studies in adults with NAFLD, however, demonstrated no significant relationship [15, 16, 36].…”