颅内真菌感染的影像学表现与鉴别诊断

Imaging Findings and Differential Diagnosis of Intracranial Fungal Infection

目的分析颅内真菌感染的影像学特点,便于作出正确影像学诊断。资料与方法10例颅内真菌感染中,真菌性肉芽肿8例,真菌性脑膜炎2例。结果颅内真菌性肉芽肿在CT上多呈混杂密度,可呈不规则、不连续性厚壁环,并有"晕征"。增强后环壁有不规则强化,肉芽肿呈结节状强化。可同时伴有鼻窦、颅底骨质破坏及钙化斑。MR示肉芽肿呈混杂T1WI信号,在T2WI上呈高信号,在高信号中间有等信号,以该等信号在增强时有明显强化为特点,有助于与颅内胶质瘤相鉴别。颅内真菌性脑膜炎广泛累及颅底或半球的脑膜,增强时见脑膜铸型强化,与常见结核性脑膜炎表现相似。结论颅内真菌性肉芽肿有一定的CT和MR表现特点,大多数能作出诊断,特别对伴鼻窦肉芽肿,颅底骨质破坏,病灶内有钙化者。真菌性脑膜炎虽有典型铸型强化,但难与结核性脑膜炎鉴别。

Objective To discuss the imaging features of intracranial fungal infection, in order to make correct diagnosis. Materials and Methods 10 patients with intracranial fungal infection were analyzed retrospectively, including intracranial fungal granuloma in 8 patients and fungal meningitis in 2 patients. Results Intracranial fungal granuloma appeared as mixed density, irregular or uncontinuous thick ring wall with a tim edema on the non-contrast enhanced CT. A ring enhancement with irregular thick and uncontinuous ring wall were depicted on the contrast enhanced CT with destruction and calcifications in sinus. Intracranial fungal granuloma appeared inhomogenous signal intensity on the T1-weighted imaging and hyperintensity signal with a patch isointensity. The patch isointensity was enhanced markedly. These imaging features were different from that of the glioma. Intracranial fungal meningitis appeared as widely meningeal involved and lumpy or nodular enhancement in the subarachnoid space of the sulci and cisterns. Conclusion Intracranial fungal granuloma has some CT and MRI imaging features. Diagnosis can be made in the most of cases, especially for the cases with granuloma in the sinus with hone destruction and calcifications. It is difficult to differentiate the fungal meningitis from the tuberculous meningitis.