[MRI findings of cerebral schistosomiasis in acute stage：establishment of experimental model of acute cerebral schistosomiasis with rabbits].

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.