The Preliminary Study Of Magnetic Resonance Diffusion-weighted Imaging Of Pancreatic Fibrosis Model In Rats

Objective:In our study, magnetic resonance diffusion-weighted imaging(DWI)were taken on pancreatic fibrosis model in rats. The changes of parameters of ADC(EADC) in different stage of pancreatic fibrosis were analyzed. As well as to explore the method for noninvasive assessing pancreatic fibrosis,to further improve the diagnosis of pancreatic fibrosis.Methods:45 healthy female Wistar rats were randomly assigned into two groups, 6 rats in normal control group, 39 rats in the experimental group. An initial dose of 400mg/kg diethyldithiocarbamate(DDC) followed by an 10% increase each time were injected in intraperitoneal twice a week in rats of experimental group,while rats in control group received intraperitoneal injections of 400 mg/kg saline twice a week.Since 3,4,5 weeks after injection,13 rats of experimental group and 2 rats of normal control group were selected randomly per week to perform magnetic resonance diffusion-weighted imaging(DWI),imaging postprocessing was performed on the images to get ADC value and e ADC value. After MR scan but in 3 hours these rats were killed and HE,Masson staining of pancreas were underwent,the pancreatic tissue samples were divided into S0~S4 groups by the pathological results. The corresponding ADC values and e ADC values of each phase of pancreatic fibrosis were calculated, analyzing the relationship among them.Results:6 rats of normal control group were survived, 31 rats of experimental group were successful,5 were unsuccessful and 3 were death. Each groups of fibrosis model:6 rats with S0,8 rats with S1,9 rats with S2,6 rats with S3,8 rats with S4. The ADC values of S0~S4 groups respectively were(988.2±17.8)×10﹣6,(845.1±19.1)×10﹣6,(787.7±16.2)×10﹣6,(709.4±15.5)×10﹣6,(632.6±8.7)×10﹣6, The e ADC values of S0~S4 groups respectively were 0.4534±0.0106, 0.5086±0.0112, 0.5325±0.0109, 0.5669±0.0120,0.6029±0.0134.It showed that there were significant differences among different fibrosis groups.Correlation analysis showed that the values of ADC(e ADC)have a good correlation with the degree of fibrosis.Conclusions:An intraperitoneal injection of incremental method of diethyldithiocarbamate with the high fat diet in rats can be established different stages of pancreatic fibrosis.The values of ADC(e ADC)have a good correlation with the degree of fibrosis and can quantitatly analysis different degree pancreatic fibrosis.