艾滋病继发弓形体脑炎的CT及MRI表现

CT and MRI manifestations of toxoplasmic encephalitis in AIDS

目的探讨艾滋病(AIDS)继发弓形体脑炎的CT及MRI表现。方法收集经临床及病理证实的AIDS继发弓形体脑炎患者30例,其中21例接受CT平扫,增强16例;24例接受常规MR检查,增强18例;15例同时接受CT和MR检查。结果本组25例病灶多发,5例单发;病灶部位多位于灰白质交界处(21例),其次为侧脑室周围(16例)、半卵圆中心(6例)、小脑(5例)、脑干(4例)、基底节区(4例)。CT平扫表现为多发斑片状、片状低密度灶,部分夹有混杂密度影;MRI表现为斑片状、块状及结节状长T1长T2信号,FLAIR序列多为高信号;增强后表现为斑片状、环状强化,以环状强化多见(13例)。本组所有病例经抗弓形体治疗后症状均有好转。结论 CT及MRI对AIDS继发弓形体脑炎有重要的诊断价值。根据MRI的特征性表现,结合临床及血清HIV、弓形体IgG及IgM抗体阳性,可对本病进行确诊。

Objective To discuss CT and MRI features of toxoplasmic encephalitis in acquired immune deficiency syndrome（AIDS）patients.Methods There were totally 30 patients which were confirmed by clinic and pathology.Twenty-one in 30 patients were examined with CT,including 16 patients underwent enhancement CT,while 24 patients were examined with MR,among which 18 patients underwent enhanced MR scan.Fifteen patients were examined with both CT and MR.Results Multiple lesions appeared in 25 patients and isolated lesions in 5 patients.Most of the focus situated at the juncture of gray and white matter of cerebral hemisphere（21 patients）,secondarily around the lateral ventricle（16 patients）,then in centrum semiovale（6 patients）,cerebellum（5 patients）,in brain stem and basal ganglia（each 4 patients）.Plain CT scan displayed lamellar low density umbra,part of them were mixed density.The lesions had long T1 and long T2 signals,and had high signal on FLAIR.They were patchy,ring-like performance after enhancement,but the ring-like performance was main feature（16 patients）.The symptoms of AIDS patients in this group were improved after symptomatic treatment.Conclusion CT,especially MRI have significant value in diagnosis of toxoplasmic encephalitis in AIDS.The final diagnosis can be determined with MRI findings combined with clinical manifestations and the blood test.