MR of Toxoplasma encephalitis: Signal characteristics on T2-weighted images and pathologic correlation
MR of Toxoplasma encephalitis: Signal characteristics on T2-weighted images and pathologic correlation
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DOI：
10.1097/00004728-199605000-00019
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发表时间：
1996-05-01
影响因子：
1.3
通讯作者：
Ruiz, A
中科院分区：
文献类型：
--
作者：
Brightbill, TC;Post, MJD;Ruiz, A
目的：我们的目的是确定弓形虫脑炎是否有任何t2加权MR信号特征，可能有助于诊断和/或衡量药物治疗的有效性。方法：回顾性分析27例经医学证实（26例）和活检证实（1例）弓形虫脑炎患者的MR、CT、铊-201 SPECT脑扫描和病历，并补充4例尸检结果，其中2例与死后MR相关。并复习了神经病理学文献。结果：在27例患者中，我们发现了三种不同的影像学模式。10例（37%）患者主要为t2加权高强度病变，平均接受药物治疗3天（不包括1例异常值）。10例（37%）患者有t2加权等强度病变，平均接受61天的药物治疗。7例（26%）患者在t2加权图像上出现混合信号病变，平均治疗时间为6天。另外4例患者的尸检资料分析显示，3例存在组织性脓肿，1例存在坏死性脑炎，而进行脑活检的患者显示两种类型的病理病变。在这两个病例的尸检MRI中，组织脓肿在t2加权图像上表现为等强度到低强度。结论：弓形虫脑炎病变在t2加权图像上有明确的变化，排除了仅基于信号特征的明确诊断。病理学上，我们的数据表明t2加权高强度与坏死性脑炎相关，而t2加权等强度与组织性脓肿相关。此外，在接受药物治疗的患者中，作为对抗生素治疗的积极反应的函数，t2加权MR表现可能是从高强度到等强度的转变，表明信号变化可用于衡量药物治疗的有效性。
Purpose: Our goal was to determine if there are any T2-weighted MR signal characteristics of Toxoplasma encephalitis that might be useful in diagnosis and/or in gauging the effectiveness of medical therapy.Method: We retrospectively analyzed the MR, CT, thallium-201 SPECT brain scans, and medical records of 27 patients with medically proven (26) and biopsy proven (1) Toxoplasma encephalitis, supplemented by autopsy findings in 4 additional patients, 2 of whom had postmortem MR correlation. The neuropathologic literature was also reviewed.Results: Among the 27 patients, we discovered three distinct imaging patterns. Ten (37%) patients had predominantly T2-weighted hyperintense lesions and had been on medical therapy an average of 3 days (excluding one outlier). Ten (37%) patients had T2-weighted isointense lesions and had received medical therapy an average of 61 days. Seven (26%) patients had lesions with mixed signal on T2-weighted images and had been on treatment an average of 6 days, Analysis of autopsy material from the four additional patients revealed the presence of organizing abscesses in three and necrotizing encephalitis in one, while the patient who had a brain biopsy demonstrated both types of pathologic lesions. In both cases having postmortem MRI, organizing abscesses appeared isointense to hypointense on T2-weighted images.Conclusion: There is a definite variation in the appearance of lesions of Toxoplasma encephalitis on T2-weighted images that precludes a definitive diagnosis based on signal characteristics alone. Pathologically, our data suggest that T2-weighted hyperintensity correlates with necrotizing encephalitis and T2-weighted isointensity with organizing abscesses. Furthermore, in patients on medical therapy the T2-weighted MR appearance may be a transition from hyperintensity to isointensity as a function of a positive response to antibiotic treatment, indicating that the signal change might be used to gauge the effectiveness of medical therapy.