艾滋病合并弓形虫脑病的影像学表现

Imaging appearance of toxoplasma encephalopathy in AIDS patients

目的探讨AIDS合并弓形虫脑病的影像学表现及特征。方法收集10例AIDS合并弓形虫脑病的临床及影像学资料,回顾性分析其头颅影像表现特点。结果 10例AIDS合并弓形虫脑病患者中共发现颅内病灶30个,每个患者病灶数目2～7个不等;结节状或类圆形病灶共20个。CT平扫所有颅内病灶表现均为低密度影,增强扫描有7个病灶出现环形强化;MRT1WI表现为低或等信号,T2WI为高信号,增强MRI有8个病灶呈环形强化,其中2个表现为"靶征",比较CD4+T淋巴细胞计数高于50cell/μl的患者和CD4+T淋巴细胞计数低于50cell/μl的患者,发现前者更易出现环形或结节状强化(卡方检验,P=0.009)。结论 AIDS合并弓形虫脑病颅内病灶影像表现为多发性,多累及大脑半球、基底节区及丘脑,病灶的形态多为结节状或类圆形,在CD4+T淋巴细胞计数相对较高的患者注入对比剂后更易呈环形或结节状强化。

Objective： To characterize the cranial imaging findings of toxoplasma encephalopathy in AIDS patients. Materials and Methods： A retrospective review of 10 human AIDS patients with toxoplasma encephalopathy was performed. Head computed tomography （CT） and magnetic resonance imaging （MRI） were reviewed. Results： There were 30 lesions found in 10 patients, the number of lesions for each patient ranged from 2 to 7, there were 20 nodular or oval lesions among the 30 lesions. Before contrast injection, all the lesions were low density on CT; after intravenous contrast injection, there were 7 lesions showed ring enhancement. For the MRI, all lesions were predominantly hypointense on Tl-weighted images, all the lesions were hyperintense on T2-weighted images. Post-contrast imaging revealed ring enhancement in 8 lesions, including 2 target enhancement. Patients with CD4＋ T lymphocyte count above 50 cell/μl compared with CD4＋ T lymphocyte count less than 50 eell/μl was more likely with ring or nodular enhancement （Chi-square test, P=0.009）. Conclusion： Toxoplasma encephalopathy showed multiple lesions, many of the lesions involved the cerebral hemispheres, basal ganglia and thalamus, the lesions form were predominantly nodular or oval, patients with relatively higher CD4＋ T lymphocyte count was of more ring enhancement after injection of contrast agent.