文摘
Purpose Assess the effect of fat deposition on the MRI diffusion coefficients in lipid emulsion-based phantoms and patients with proven isolated liver steatosis. Materials and methods Diffusion-weighted MRI with 11 b values from 0-00?s/mm2 was performed in phantoms (fat fractions 0-8?%) with and without fat suppression and in 19 patients with normal liver (n--4) or isolated liver steatosis (n--) proven by histopathology. The apparent, pure and perfusion-related diffusion coefficients and the perfusion fraction were measured. Spearman correlation coefficient and Mann–Whitney U test were used for comparisons. Results A strong correlation between the apparent and pure diffusion coefficients and fat fractions was seen in phantoms. The pure diffusion coefficient decreased significantly in patients with liver steatosis (0.96?±-.16?×-0-3?mm2/s versus 1.18?±-.09?×-0-3?mm2/s in normal liver, P--.005), whereas the decrease in apparent diffusion coefficient did not reach statistical significance (1.26?±-.25?×-0-3?mm2/s versus 1.41?±-.14?×-0-3?mm2/s in normal liver, P--.298). Conclusions Fat deposition decreases the apparent and pure diffusion coefficients in lipid emulsion-based phantoms and patients with isolated liver steatosis proven by histopathology. Key Points -Magnetic resonance imaging is increasingly used to quantify hepatic fibrosis. -Lipid phantoms show inverse correlations between diffusion coefficients and fat fractions. -The pure diffusion coefficient decreases in patients with isolated liver steatosis. -Steatosis may be a confounding factor when measuring the liver diffusion parameters.