| Purpose1.To discuss factors like administered methods,contrast agent and its doses and Micro-CT system parameters like angle of increment and resolution,which may influence perfusion image of Micro-CT contrast enhancement applied in liver blood vessels in mice.At the end,to determine a liver contrast enhancement scan scheme.2.The establishment of liver alveolar hydatid infection animal model in mice to confirm it.Methods1.To compare three kinds enhanced effects of common medical contrast media include Iohexol,Urografin and Ultravist Solution.Thirty normal mice by tail vein administered,were randomly divided into three different groups:group I(Iohexol administered), II(Urografin administered) and III(Ultravist administered).The better contrast agent was selected for the following experiments.2.Based on the above results,thirty male kunming mice were randomly divided into three different groups: group I(intraperitoneally administered), group II(tail vein administered)and control group(normal saline injection). Group I and II were executed with Iohexol in different dose(100μl,150μl,200μl,250μl,300μl)respectively; control group adopted normal saline with same dose as experimental group. We have to find the best way to deliver the contrast enhancement scanning on liver as well as the suitable injecting method and contrast agent dose.3.Based on the above results,to compare various Micro-CT scanning result by changing angle of increment(1.1°,0.9°and 0.7°) and resolution ratio(35μm,18μm and 9μm) separately,and find the best scheme for enhanced scanning on liver.4. First, it is verified whether the scheme can be used in the enhancement of the model.A total of male mice model infected with Alveolar Echinococcusis to observe the effect of the liver blood vessel enhancement imaging.In order to verify the role of anti-hydatid drugs,we choose the representative drug, the chitosan microspheres,and then these animals were divided into three groups, which were interfered by different agents in same dose, administered method and cultivation period: experimental group by Chitosan microsphere drug(regular intragastric administration for ten weeks); conditional control group by normal saline for ten weeks; blank control group by normal saline for ten weeks.We used the technique stated before to make micro-CT scanning biweekly and dynamically observed the effect of drugs on hydatid vesicle.Results1.The three kinds of contrast agent can successfully filling blood vessels, and we found the effect of iodine contrast agent is better than others by imaging.2.The I and II group can smoothly fill body and the effect in group II is better than group I by imaging,while the control group showed no effect.3.Decreasing angle of increment could improve image quality and choosing the appropriate resolution(18μm) could expedite the scan time.4.Among the study of 30 animal models,two died by taking an overdose anesthetic and one died by an overdose contrast agent,the remaining can be successfully.Finally, the restdisease mode is used to verify this scheme’s efficiency.By scanning we found that in experimental group, images showed A.E in spherical shape with decreasing size and low-density shadow; in conditional control group, images also showed A.E in spherical shape with low-density shadow but stable size; the blank control group manifested no low-density shadow.Conclusion1.Common used Iohexol can replace the costly professional contrast agent and others.2.After attempts from different perspectives,we found ideal scan parameters that met the requirements of imaging of mouse specimens: Tube voltage 50 kVp and tube current 480μA and filter 0.5mmAl were used; the resolution is 18 μm,360 degree views were obtained at 0.7degree increments around the subject.3.Based on the scanning,can be observed the enhanced effect of the liver blood vessel successfully and basic research for liver disease. |
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