颅内血管外皮细胞瘤的常规MRI和灌注成像

目的 探讨颅内血管外皮细胞瘤(HPC)的常规MRI和灌注成像(PWI)表现，评价两者对HPC的诊断价值。方法 收集5例经手术和病理证实的HPC患者，并以38例脑膜瘤作为对照，行常规MRI和PWI检查，观察HPC和脑膜瘤的MRI表现，计算并比较两者的相对局部脑血流容积(rrCBV)和相对平均通过时间(rMTT)。结果 T1WI上等信号3例，混杂信号2例；T2WI上混杂信号3例，等信号2例；增强后均明显强化。HPC的常规MRI表现与脑膜瘤难以鉴别。PWI时，HPC的rrCBV和rMTT分别为14．4、5．3，而脑膜瘤则为6．5、3．6，两者的rrCBV有显著统计学差异，而rMTT则无明显差异。结论 HPC的常规MRI表现不具特征性，难与脑膜瘤相鉴别；但PWI在HPC的诊断中具有重要作用。

Conventional MRI and Perfusion Weighted Imaging of Intracranial Hemangiopericytoma

Objective To investigate the conventional MRI and perfusion weighted imaging features of intracranial hemangiopericytoma (HPC),and to evaluate the potential in diagnostic accuracy.Methods Five patients with pathologically proved intracranial HPC were collected,38 patients with meningioma were used as control,all of them were performed with conventional MRI and perfusion weighted imaging.MRI features were observed,and relative regional cerebral blood volume (rrCBV) and relative mean transit time (rMTT) were calculated.Results On T1WI,the HPC lesions displayed inhomogeneous signal in 3 and iso-signal in 2 cases.On T2WI,iso-signal was seen in 3 cases,and inhomogeneous signal in 2 cases.All of lesions showed marked enhancement after injection of Gd-DTPA,which could also be seen in meningiomas.The rrCBV and rMTT were 14.4,5.3 in HPC,the values were 6.5 and 3.6 in meningioma.There was statistically significant difference in rrCBV between two the groups,but no difference in rMTT.Conclusion On conventional MRI,intracranial HPC has no pathognomonic signs,and it was difficult to differentiate HPC from meningioma,but PWI is very useful.