实验性脑脓肿影像学改变的病理基础研究

Correlation of CT MRI and pathology in experimental brain abscess

目的：明确不同时期动物脑脓肿的影像学特征及其相应的病理学改变。方法：制备脑脓肿狗动物模型１４只，采用ＣＴ、ＭＲＩ检查结合多项病理学观测进行动态分析。结果：脑炎期ＭＲＩ对炎症坏死区及水肿范围的显示较ＣＴ扫描更为清晰准确。包膜形成期：ＣＴ上脑脓肿包膜强化是炎症区血脑屏障破坏和新生血管形成所致；ＭＲＩＴ２加权成像上包膜的低信号“暗带”与包膜上的巨噬细胞堆积有关，延迟扫描和ＭＲＩ均能有效地区分脑脓肿的急性脑炎期和包膜形成期，但ＭＲＩ更加准确、迅速。结论：脑脓肿的ＭＲＩ特征与其临床分期及病理学变化的相关性较好，能更加准确、简便、迅速地区别脓肿的脑炎期和包膜形成期，可作为临床诊治脑脓肿的有力参考。

Objective: To study the correlation of CT, MRI and pathology in experimental brain abscess. Methods: An experimental model of brain abscess in dogs was established. The features of CT, MRI and pathological examinations in various stages of brain abscess had been studied. Results: MRI proved more sensitive than CT in diagnosis of cerebritis stage and detecting cerebral edema. MRI also offered more advantages than CT in reflecting range of central necrotic and histological criteria. During capsule stage, ring enhancement caused by the destruction of blood brain barrier and abnormal permeability capsule neovascularity in inflammatory area could be shown on CT image. The hypointense rim on T2 weighted of MRI is likely due to the presence of accumulation of macrophages in the capsule wall. MRI is more sensitive than CT to distinguish the cerebritis stage from the capsule stage. Conclusion: MRI features of brain abscess were well corelated to the clinical stages and pathological changes. MRI is powerful in the determination of clinical stages of brain abscess.