脑内型表皮样囊肿的CT和MRI诊断

CT and MRI Diagnosis of Intracerebral Epidermoid Cysts

目的探讨脑内型表皮样囊肿的CT和MRI影像表现特点,提高对脑内型表皮样囊肿影像诊断的准确性。资料与方法回顾性分析5例经手术病理证实的脑内型表皮样囊肿患者的CT和MRI影像资料。5例患者均行CT平扫检查,其中4例行CT增强检查。5例患者中4例行MRI平扫检查,其中2例行MRI增强检查。结果 5例中,3例位于小脑半球,1例位于基底节区,1例位于额叶。肿瘤呈不规则形或分叶状,与周围组织分界清晰。CT平扫为较均匀或轻度不均匀低密度,CT值-22～26 HU之间。MRI平扫T1WI上肿瘤呈不均匀低信号,内部可见散在絮状略高信号;T2WI及液体衰减反转恢复(FLAIR)图像上呈不均匀高信号。CT及MRI增强检查病灶均无明显强化。结论脑内型表皮样囊肿的CT、MRI表现较具有特征性,尤其是MRI对其诊断有重要价值。

Objective To explore the CT and MRI features of intracerebral epidermoid cysts and to improve the accuracy of diagnosis.Materials and Methods The CT and MRI images of 5 patients with intracerebral epidermoid cysts confirmed pathologically were analyzed retrospectively.All patients underwent CT precontrast examinations,among which CT postcontrast scanning was performed in 4 patients.Four of the 5 patients also underwent MR postcontrast scanning,among which MR postcontrast scanning was performed in 2 patients.Results Among the 5 cases of intracerebral epidermoid cysts,3 lesions were located in cerebellum,1 in basal ganglia,and 1 in frontal lobe.Irregular or lobulated shapes and well-defined border were noted in all leisions.On pre-contrast CT,5 cases were homogeneous hypodense or slightly inhomogeneous hypodense from-22 to 26 HU in CT values.The lesions presented inhomogeneous hypointensity signal on T1-weighted precontrast MR images with dispersed cotton-shaped zone of slight hyperintensity signal noted inside,and inhomogeneous hyperintensity signal on T2-weighted and FLAIR MR images.No contrast enhancement was demonstrated in all leisions.Conclusion CT and MRI features of intracerebral epidermoid cysts are relatively characteristic,and MRI could play an more important role to the diagnosis.