Inflammatory Pseudotumor Of The Liver: Rabbit Model Establishment And Study Of DWI

Background: Magnetic resonance diffusion-weighted imaging(DWI) has been used in many diseases of central nervous system, but were restricted in the use of abdominal imaging, because of the movement of breathing exercise and other factors affecting the imaging quality. With the development of magnetic resonance technology, diffusion-weighted imaging of abdominal organs had become possible. Mainly the study of DWI of liver concentrated on clinical research and the reports of animal liver were rare. Hepatic pseudotumor is a rare benign lesion, induced by a long-term role of various pathogenic factors and formed an inflammatory and hyperplastic mass. With the improvement and popularization of the medical imaging equipment and technologies, there is a tendency that clinical IPL cases are growing. It is quite easy to misdiagnose IPL as liver cancer due to the lack of imaging characteristic, therefore, further strengthening the study for IPL has important significance.Objectives: Through the establishment of inflammatory pseudotumor of the liver(IPL) rabbit animal model, studying its MRI and DWI's features, to investigate the values of MR DWI in diagnosing inflammatory pseudotumor of the liver.Methods: 20 ordinary rabbits (weight 2.0~ 3.0kg, the average weight of 2.5kg) were randomly divided into two groups , group A for the control group, group B for the experimental group. The experimental group of rabbits model were made by CT-guided percutaneous intra-liver injection of 1.0 ~ 1.5ml Freund's adjuvant, while the control group were made by injecting of 1.0 ~ 1.5ml normal saline. Two weeks later, the two group of rabbit liver were scanned by conventional and DW imaging sequences. After scanning all rabbits were sacrificed by air embolism, then the incidence and patterns of hepatic pseudotumor were observed and HE staining of the pseudotumors'specimens were finally made. The pathology results, magnetic resonance imaging and DWI of the two groups of animals were analysed. Then we obtained ADC and eADC of liver with software. SPSS packages 13.0 was used for statistical analysis, using independent samples t test between the control group and experimental group, one-way ANOVA and least significant difference method (LSD) test among the experimental group.Results:1. The animal modal of inflammatory pseudotumor of the liver of rabbit were successfully finished in 90% with the diameter 1.5±0.5cm;2. Comparison of ADC and eADC of the experimental group of rabbit liver disease and liver in the control group rabbits of under different b value (1) ADC values under different b values between the experimental group and the control group were statistically significant differences (P <0.05);(2) eADC values under different b values between the experimental group and the control group were statistically significant differences (P <0.05);(3) ADC and eADC values have statistically significant differences between among the experimental group.3. Pseudotumor was showed hyper-intensity on DWI , the ADC values of IPL was lower than that of normal liver parenchyma, eADC value higher than that of normal liver parenchyma; with the increasing of b value, gradually ADC values decreased and eADC value increased.4. In inflammatory pseudotumor of the DWI imaging, b values from 300-600 for the best Conclusion: The inflammatory pseudotumor of the liver of rabbit animal models were set up successfully by CT-guided percutaneous intra-liver injection of Freund's adjuvant. The combination of T1WI, T2WI and DWI was better at showing the liver tumors. The use of ADC values and eADC values can further improve diagnostic accuracy.