Accurate fat fraction quantification by multiecho gradient-recalled-echo magnetic resonance at 1.5 T in rats with nonalcoholic fatty liver disease

AimTo assess the diagnostic accuracy of a new reconstruction technique for gradient-recalled-echo magnetic resonance (MR) sequences that provides a full decomposition of the water and fat content inside a voxel for nonalcoholic fatty liver disease (NAFLD) in rats.Material and methodsRats were randomized into two groups. A control group (n = 10) was given free access to regular dry rat chow for 4 weeks. The steatosis (n = 40) group was given free access to feed and water 4 days per week, and fasted for the remaining 3 days for 4 weeks. All rats were killed at 4 weeks and assessed for fatty infiltration and biochemical method.ResultsThe average fat content using the gold standard method was 2.65 g (2.20–3.05) of fat/100 g liver for the control group and 4.14 g (1.95–8.60) of fat/100 g of liver for the overfed group (p < 0.05). The average fat-fraction obtained from the MR was 0.016 (0.01–0.02) for the control group and 0.057 (0.00–0.18) for the overfed group. The Pearson correlation coefficient between the samples was r2 = 0.87.ConclusionMulti-echo MR is a good technique to quantify liver fat in rats.