Abstract: Objective To establish an experimental model of acute cerebral schistosomiasis japonica and explore the MRI manifestations of acute cerebral schistosomiasis. Methods Rabbits were divided into 3 groups with 10 rabbits in each group. The rabbits in the experimental group were directly injected with suspension fluid of Schistosoma japonicum eggs （0.9 mg， 1 ml） by the cranial drilling method， those in the negative control group were given saline （1 ml） by the same method above?mentioned， and those in the blank control group were not given any treatment. Antibiotic was given to the first two groups after the operation. The clinical manifestations of the 3 groups were observed， and the magnetic resonance imaging （MRI） was performed in 30 days post?operation， and then the brain tissues were taken for pathological examinations. Results All the rabbits in the experimental group exhibited inappetence， various neurological symptoms including hemiplegia， and weight loss after the operation； while those in the negative control group showed inappetence in 3 days after the operation， and 1 week later， the symptom disappeared； there were no adverse reactions in the blank control group. MRI of the experimental group showed nodular or patchy enhancement on T1WI enhancement， brain edema， abnormal ventricular dilatation， and needle augmentation. SWI displayed hypointense in the abnormal enhanced nodules and flaky hypointense on the operation brain. In the negative control group， 2 rabbits showed abnormal enhancement of the needle canal， and 1 showed mild dilatation of the ventricle. The blank control group showed normal manifestations. The pathological examinations showed abnormal appearances in 10 rabbits of the experimental group， including 6 with S. japonicum egg granuloma nodules， nonspecific granuloma nodules coexisted with perivascular inflammation； no granuloma nodules were found in the negative control group， but 2 rabbits showed vascular inflammation； the blank control group showed the normal brain tissue. Conclusions An experimental model of acute cerebral schistosomiasis is successfully established in rabbits by intracranial injection of schistosome eggs. The MRI examination combined with the clinical manifestations can improve the accuracy of early diagnosis of cerebral schistosomiasis.

Key words: Schistosoma japonicum； Cerebral schistosomiasis； Magnetic resonance imaging （MRI）； Animal model； Egg granuloma

摘要： 目的 建立家兔急性脑型血吸虫病模型，探讨急性血吸虫脑病早期磁共振表现。方法 家兔分3组，每组10只；实验组通过钻颅法注射日本血吸虫虫卵悬浮液1 ml （0.9 mg）；阴性对照组用相同方法经颅注射生理盐水1 ml；空白对照组不做任何处理。前两组术后使用抗生素预防感染。观察3组动物的临床表现，并于术后30 d行头颅磁共振检查；随后取脑组织制作病理切片，观察脑组织病理改变。结果 实验组家兔术后均出现食欲不振、精神异常，偏瘫及体重下降等症状；阴性对照组家兔术后3 d内均出现食欲下降，1周后消失，无异常精神症状；空白对照组无不良反应。实验组10只家兔磁共振表现均发现异常，表现为T1WI增强，出现片状、结节状强化，脑水肿，脑室扩张，注射针道异常强化，SWI脑内强化结节内异常点低信号及手术侧脑半球内片状低信号。阴性对照组2只磁共振表现为针道异常强化， 1只脑室轻度扩张。空白对照组磁共振表现无异常。实验组10只脑组织病理切片均发现异常，其中6只为血吸虫虫卵肉芽肿结节、非特异性肉芽肿结节以及血管周围炎并存；阴性对照组未发现肉芽肿结节，2只出现血管周围炎；空白对照组脑组织切片正常。结论 经颅注射血吸虫虫卵可成功建立家兔急性血吸虫脑病模型；通过观察磁共振图像总结早期血吸虫脑病表现，有助于提高早期诊断的正确率。

关键词: 日本血吸虫；脑型血吸虫病；磁共振成像；动物模型；虫卵肉芽肿