Study Of Energy CT And 3.0T MRI Quantitative Diagnosis In Rabbit Steatohepatitis Model

Objective: Establishing rabbit steatohepatitis models and making a relevant analysis with pathological results to investigate the diagnostic value of dual-energy CT and 3.0T MRI with fatty liver.Materials and methods:1. Subject50 adult male New Zealand white rabbits were randomly divided into group A and group B. 42 rabbits were taken as the group A, 32 were selectde as experimental group and the remaining 10 rabbits were used as the backup group.8 rabbits were taken as the group B(the control group). Group A were reared with high fat diet and Group B were reared with regular diet for 16 weeks. CT value on different tube voltages of SECT, CT value on different monochromatic energy image of DECT, MRI hepatic fat fraction (HFF) and proton density fat fraction ( PDFF) were measured and recorded. After CT and MRI scan, liver pathologic samples were obtained by using acid-catalyzed hydrolysis method.2. Statistical analysisAll count indicator were input SPSS 16.0 statistical package (population mean, one-way ANOVA analysis, LSD test, Pearson correlation analyse, etc.), A P value of< 0.01 was considered statistically significant.Result:1. In group A, 32 fatty liver model that were required in experimental group were completed the process; 6 rabbits were mild fatty liver, 23 rabbits were moderate fatty liver, 3 rabbits were severe fatty liver. 8 rabbits dead. The success rate of establish rabbit model is 81.0%, the mortality rate is 19.0%; all 8 rabbits of the control group were complete experimental process.2. All CT values at conventional CT scans under 140 kv and dual-energy CT scanning under each monochromatic energy image, DFF and HFF of normal and mild fatty liver have no significant difference (P > 0.01), the CT value of other comparison have remarkable difference in statistics(P < 0.01).3. Pearson correlation analysis showed a negative relation between CT values and pathological results. A positive relation between PDFF, HFF and pathological results (P <0.01) was found. The correlation between the CT value of Conventional CT scans that perform under 100 kv and pathological results is the best (r=-0.954). The correlation between MRI PDFF and pathological results is better than HFF (r=0.936).4. The maximum area under curve of CT value was conventional CT scan under 80 kv, the area was 0.996 and the threshold value was 57.06Hu; The maximum area under curve of MRI was PDFF, the threshold value was 2.58%.Conclusion(1) It is a simple, convenient, repeatable method to create a steatohepatitis model with high fat diet;(2 ) Using CT scan to quantitative assess fatty liver have great effect. CT value of SECT scan under 100kv have the best correlation with liver fat content;(3 ) In-opposed phase sequence and IDEAL-IQ sequence can be used for quantitative diagnosis of liver steatosis. The correlation between IDEAL-IQ sequence and liver fat content is better.