| Objective:The MRI features of mouse hepatic alveolar echinococcosis at different stages were analyzed by 7.0T magnetic resonance to explore the growth characteristics of mouse hepatic alveolar echinococcosis.Methods:30 SPF Balb/c mice purchased from SBF Biotechnology Co.,Ltd company were selected,weighed and caged.5 mice in each cage were fed in the SPF animal room of central laboratory of affiliated hospital of Qinghai University laboratory.The mouse model of hepatic alveolar echinococcosis was established after feeding for 5-6 weeks.A long clawed gerbil successfully infected with alveolar echinococcosis,provided by central laboratory of affiliated hospital of Qinghai University laboratory,was killed by cervical scission,then the vesicle mass containing alveolar echinococcosis was removed,removed excess tissue,sheared,filtered,rinsed,and prepared into a suspension of alveolar echinococcosis,Each Balb/c mouse pierced the right abdominal cavity with a 1ml syringe,and then injected 200μL of suspensionpieces of alveolar echinococcosis at a depth of about 1cm.At week 2 of inoculation,ultrasound screening was performed on the whole mouse model,26 mouse models successfully infected with HAE were screened and housed in cages.As required by the experimental requirements,5 mice were selected from the successful mouse model of hepatic alveolar echinococcosis at 2th weeks,8th weeks,12 th weeks,16 th weeks,20 th weeks of inoculation for 7.0T magnetic resonance scanning.Each examination was performed according to a standardized operating procedure.Mice were anesthetized by inhalation before examination,and breathing was observed with the respiratory rate controlled at40-60 breaths / min.After smooth breathing and complete anesthesia,the mice were fixed on the scanning table of 7.0TMRI system,prone position,and the peripheral gap was filled with gauze,so that the liver of the mice was located in the center of the magnetic field.The appropriate scanning parameters were selected by pre scanning,and then the standard transverse axial position of mouse liver was scanned by Fast Imaging using Low Angle Shot sequence,followed by T1 weighted image,T2 weighted image and diffusion weighted imaging sequence.The whole scanning process was triggered by respiratory gating.The site,maximum diameter,morphology,boundaries,signal,relationship with surrounding tissue,etc.were recorded in detail for the obtained scanned images.The experimental mice were killed at the end of the experiment,and the pathological specimens were taken for routine HE staining.Results:(1)Analysis of distribution and morphological characteristics of intrahepatic lesions: The lesions were mostly located along the main portal vein trunk and branch.At 2 and 8 weeks after inoculation,the lesions were mainly distributed in the portal of liver,and at 20 weeks after inoculation,they were mainly distributed in the right lobe of liver.Multiple vesicular lesions are the characteristic MRI findings of HAE in mice.Multiple small vesicles can be seen around the lesions.With the extension of inoculation time,small vesicles gradually gather and fuse into larger lesions.(2)Relationship between lesion diameter and inoculation time: There was a positive correlation between the maximum diameter of lesions in left lobe,right lobe and hilar of liver and inoculation time(r =0.771,0.859,0.866,P<0.05).There was a positive correlation between the maximum diameter of intrahepatic single cystic,multi cystic and cystic solid lesions and the inoculation time(r = 0.661,0.811,0.586,P< 0.05).In the same inoculation cycle,the difference of maximum diameter between different forms of lesions was significant(P<0.05).(3)Analysis of lesion growth characteristics: Mouse HAE lesions showed low signal on T1 WI,high signal on T2 WI and low signal on DWI.Solid components were found in some HAE lesions,which showed equal signal on T1 WI and T2 WI,equal and high signal appeared on DWI.(4)Analysis of the biological activity of the marginal zone of the lesions: The HAE marginal zone of mice at 2 and 8 weeks after inoculation was hyperintense and continuous.At 12 and 16 weeks after inoculation,the edge band of HAE lesion in mice was hyperintense,continuous,showed clear tendency to the hilar direction,and the extrahepatic margin showed less clearing.At 20 weeks after inoculation,the signal in the marginal zone of HAE lesions decreased and the continuity was poor.(5)Analysis of portal vein invasion: The invasion of the portal vein is mainly the main portal vein main trunk and the left branch.There was a significant difference(P<0.05)between the maximum diameter of the lesion in the group with an invaded portal vein and that in the group without an invaded portal vein.(6)Intraperitoneal lesion analysis: The MRI findings of intraperitoneal lesions are similar to those of intrahepatic lesions.There was a correlation between the maximum diameter of the lesion and the time of inoculation.The intra-abdominal lesions grew faster than the intrahepatic lesions in the same period,and the maximum diameter of the lesions was large.Conclusion:Dynamic intravital noninvasive monitoring of the course and growth properties of HAE lesions at the live level by MR serial scanning of HAE mouse lesions with 7.0T magnetic resonance is highly valuable for the early detection and diagnosis of HAE disease. |
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