脑血吸虫性肉芽肿CT和MRI表现与分型探讨

目的 探讨脑血吸虫性肉芽肿的CT和MRI的表现特征和影像学分型。方法 回顾性分析经手术病理及临床证实的脑血吸虫性肉芽肿30例。采用GE MAX640 CT机及GE Signa 0．2 T开放式永磁型MRI仪，分别进行平扫及增强扫描。结果 幕上大脑27例，幕下小脑3例。CT平扫病变呈等或稍高密度，MR平扫T1WI大多呈等或稍低信号，T2WI呈高信号但低于脑脊液信号，液体衰减反转恢复序列呈稍高信号。CT与MRI增强表现为：脑皮层或皮层下区多发或单发大小不等强化结节。根据结节的形态大小及增强特征分为4型：(1)多发小结节型5例；(2)单发大结节型8例；(3)混合结节型14例；(4)环状强化结节型3例。结论 脑血吸虫性肉芽肿有较典型的CT、MRI表现；影像学分型有利于诊断和鉴别诊断，并可为治疗提供有价值的参考。

CT and MRI findings and classification study of brain schistosomiasis granuloma

Objective To study CT and MRI features and classification of brain schistosomiasis granuloma. Methods CT and MRI data of 30 cases of brain schistosomiasis granuloma were reviewed.All cases were proved by the surgery or pathological examination and clinical laboratory test.There were 20 males and 10 females, and their age ranged from 5 to 58 years, mean 29.2 years.Plain and enhanced CT were performed in all patients with GE MAX 640 scanner.Ten patients were examined by plain and enhanced MRI with GE Signa profile 0.2 Tesla open scanner.Results The lesions located in supratentorial region in 27 cases and in infratentorial region in 3cases.The nodules were isodense or slight hyperdense on CT plain scan, iso or hypointense on T_1WI, hyperintense on T_2WI, Slight hyperintense on FLAIR.After the contrast material was injected intravenously, CT and MRI findings were multiple or single enhanced nodules at the cortical or subcortical area.There were four types of imaging features: (1) multiple small nodules in 5 cases (presenting as bright stars in the dark sky); (2) single large nodule in 8 cases; (3) mixed nodules in 14 cases; (4) circle-enhanced nodules in 3 cases.Conclusion The brain schistosomiasis granuloma has typical CT and MRI findings.CT and MRI classification is not only helpful to its diagnosis and differential diagnosis, but also might be useful for the choice of clinical treatment.