颅内皮样囊肿的MRI和CT诊断

目的探讨颅内皮样囊肿的MRI和CT表现及其诊断价值。方法回顾性分析23例经手术病理证实的颅内皮样囊肿病例，对其MRI和CT表现、病理和临床特征进行分析。23例均行MRI检查，20例同时行CT检查。结果22例MRI表现T1WI和T2WI均为不均匀高信号，1例T1WI为等高信号，T2WI为低信号。8例DWI表现斑片状不均匀高信号。19例CT标准窗宽、窗位，表现为均匀低密度影，宽窗宽、低窗位，表现为不均匀低密度影。另1例CT标准窗宽、窗位，表现为高密度影。其中8例CT和MRI可见蛛网膜下腔和双侧脑室内散布的脂肪滴和间质性脑水肿。结论颅内皮样囊肿有较典型的MRI和CT表现，特别是皮样囊肿破裂有影像学和临床特征性表现，可实现术前正确诊断，MRI优于CT诊断。

MRI and CT representations of intracranial dermoid cyst

Objective To evaluate the MRI and CT representations and their valuation of intraeranial dermoid cyst. Methods 23 cases who suffered from intracranial dermoid cyst confirmed by pathology were included retrospectively. The MRI and CT representations, and the pathological and clinical characteristics were analyzed.All the cases were performed with MRI, and 20 cases were performed with CT at the same time. Results 22 cases showed inhomogeneous high signal intensity in T1WI and T2WI, 1 cases showed iso-high signal intensity in T1WI and low signal intensity in T2WI. 8 cases showed plaque-like inhomogeneous high signal intensity in DWI. 19 cases showed homogeneous low density in CT scans with standard window width and level ,amt showed inhomogeneous low density with large window width and low window level. One case showed high density in CT scans with standard window width and level. Fat drop in subrachnoid space and bilateral cerebral ventricle and interstitial brain edema were found in 8 cases with MRI and CT. Conclusion Intracranial dermoid cyst always have typical MRI and CT representations. Distinctive representations could be found when the rupture of dermoid cyst exist, and correct diagnosis could be made before operation. MRI is better than CT in the diagnosis of dermoid cyst.