Two-point Dixon in phase and out of phase technique evaluation of non-alcoholic fatty liver disease

Abstract

Objective To investigate the diagnostic value of two-point Dixon in-phase and out of phase technique based on magnetic resonance imaging(MRI)in non-alcoholic fatty liver disease(NAFLD)and its severity, a rat diet model was established. Methods Thirty male Wister rats aged 4 weeks were randomly divided into the high-fat group and the normal group by random number table method, 15 rats in each group.The normal group was fed with normal diet, namely 100% basic feed.The high-fat group was fed with high-fat feed, and both groups were fed for 16 weeks.After 16 weeks, the abdominal axial Dixon scanning in the same phase and out of phase was performed, and the signal intensity of the same in phase and out of phase images of the left and right lobe of the liver in the two groups was measured, and the liver fat fraction(HFF)value of the high-fat group and the normal group was calculated.After the scanning, the rats were fasted for 12 hours for pathological examination, and Image ProPlus software was used to count the fatty cells.One-way ANOVA was used to analyze the pathological grading between groups, and Pearson correlation was used to analyze the relationship between the pathological grade of NALFD and HEF. Results In the high-fat group, 15 rats were classified as NAFLD, grade 1 and 2, and steatotic cells were about 18%.6 at grade 2, with about 60% of the steatotic cells; at grade 3, there were 7 steatotic cells, about 89%.All the 15 experimental mice in the normal breeding group were confirmed as free of fatty liver, and Brunt was 0.The HFF values of the experimental rats without fatty liver in the normal feeding group were(0.03±0.04), and those in the high-fat feeding group were(0.15±0.03), (0.26±0.03), and(0.31±0.02), respectively.The difference in HFF values between the four groups was statistically significant(F=58.26, P<0.05). The HFF value of grade 3 fatty liver rats was significantly higher than that of grade 1(U=2.767)and grade 2(U=2.058), and the difference was statistically significant(P<0.05). There was a significant positive correlation between HFF and the percentage of fat variable cell in liver cells(r=0.85, P<0.05). Conclusion The in phase and out of phase MRI imaging technique based on two-point Dixon technique may have high value in diagnosis and judgment the degrees of non-alcoholic fatty liver disease. Key words: Non-alcoholic fatty liver disease; MRI in phase and out of phase imaging; Fatty cell count