目的 探讨小脑蚓部寄生虫病的 临床特点并分析患者主要MRI表现。方法 选择我院2011年1月-2015年8月收治46例 小脑蚓部寄生虫病患者进行研究，对患者 年龄、临床症状等进行总结，并行头颅 MRI检查，分析小脑蚓部寄生虫病不同分 期的MRI表现。结果 小脑蚓部寄生虫病 临床特点：以癫痫为主要首发症状、饮 食习惯不良、男性发病率高于女性、青壮 年好发。MRI特点：散在单个寄生，病灶 小、数量多、分布广，76.2%(35/46)的患 者为多发病灶。46例患者中，共存期24例 (52.2%)、退变死亡期9例(19.6%)、钙化 期13例(28.32%)。MRI表现：(1)共存期多 示单个圆形或卵圆形病灶，囊壁及头节不 强化，囊内可见点状头节。T1低信号、头 节点状高信号；T2高信号、头节点状低信 号。(2)退变死亡期虫体增大、不规则， T1示囊虫壁不规则环状或结节状高信号、 虫体及周围水肿区低信号；T2示虫体及周 围水肿区为高信号、囊虫壁不规则环状或 结节状低信号，形成寄生虫病特异性改 变—靶型病灶。病灶呈结节状或不规则环 状明显强化。(3)钙化期病灶表现为无信 号或单个或多个点状低信号，无水肿带、 增强无变化。结论 小脑蚓部寄生虫病临 床特点与MRI表现均具有较大特征性，二 者结合往往可准确诊断。

Objective To summarize the clinical characteristics of cerebellar vermis parasites and to analyze the main MRI findings of the disease. Methods Fourty-six cases of patients with cerebellar vermis parasites who were admitted in our hospital from January 2011 to August 2015 were selected as the study object. Patients' age and clinical symptoms, etc. were analyzed. Head MRI examination was performed. The MRI findings of cerebellar vermis parasites of different stages were analyzed. Results Clinical characteristics: the bad eating habits, the incidence rate of male patients was higher than that of female ones, young adults were high-risk age group and epilepsy was the first symptom. MRI findings were scattered in a single parasite, with presence of small lesions, large number and wide distribution. 76.2% (35/46) were multiple lesions. There were 24 cases (52.2%) in coexistence phase, 9 cases (19.6%) in degeneration and death phase and 13 cases (28.32%) in calcification phase. MRI findings: (1)there was single round or oval shaped low-density lesion shown in coexistence phase. Cystic wall and scolex were not enhanced. There was presence of punctiform scolex in sac. The lesion show mainly low signal on T1WI but high signal of punctiform scolex. The lesion show mainly high signal on T2WI but low signal of punctiform scolex. (2)The body of parasites was enlarged in degeneration and death phase irregularly. On T1WI, it showed irregular ring or nodular high signal on parasite wall and low signal in body of parasites and surrounding edema area; On T2WI, it showed high signal in body of parasites and surrounding edema area and irregular ring or nodular low signal on parasite wall, forming specific changes of parasitic disease: target type lesions. The enhancement of lesions was significant, with nodular or irregular ring enhancement. (3)There was no signal or single or multiple punctiform low signal in calcification phase, without edema area and changes of enhancement. Conclusion The clinical characteristics and MRI findings of cerebellar vermis parasites are characteristic. The combination of the two can make accurate diagnosis.