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Fat deposition decreases diffusion parameters at MRI: a study in phantoms and patients with liver steatosis

2012; Springer Science+Business Media; Volume: 23; Issue: 2 Linguagem: Inglês

10.1007/s00330-012-2626-8

1432-1084

Helena S. Leitão, Sabrina Doblas, Gaspard d’Assignies, Philippe Garteiser, Jean‐Luc Daire, Valérie Paradis, Carlos F. G. C. Geraldes, Valérie Vilgrain, Bernard E. Van Beers,

Radiomics and Machine Learning in Medical Imaging

Assess the effect of fat deposition on the MRI diffusion coefficients in lipid emulsion-based phantoms and patients with proven isolated liver steatosis. Diffusion-weighted MRI with 11 b values from 0–500 s/mm2 was performed in phantoms (fat fractions 0–18 %) with and without fat suppression and in 19 patients with normal liver (n = 14) or isolated liver steatosis (n = 5) 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. 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 ± 0.16 × 10-3 mm2/s versus 1.18 ± 0.09 × 10-3 mm2/s in normal liver, P = 0.005), whereas the decrease in apparent diffusion coefficient did not reach statistical significance (1.26 ± 0.25 × 10-3 mm2/s versus 1.41 ± 0.14 × 10-3 mm2/s in normal liver, P = 0.298). Fat deposition decreases the apparent and pure diffusion coefficients in lipid emulsion-based phantoms and patients with isolated liver steatosis proven by histopathology. • 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.