颅内血管外皮细胞瘤的CT和MRI诊断

CT and MRI Diagnosis of Intracranial Hemangiopericytoma

目的:探讨颅内血管外皮细胞瘤(HPC)的CT和MRI特征及其诊断价值。方法:回顾性分析15例经手术病理证实的颅内HPC的CT及MRI资料。结果:15例肿瘤均位于颅内脑外,幕上12例,幕下静脉窦旁3例。10例呈不规则分叶状,5例呈类圆形或椭圆形。6例行CT平扫及增强:平扫稍高密度,3例伴囊变、坏死;增强后均明显强化,2例伴脑膜尾征。15例行MRI常规平扫、DWI及增强:T1WI上4例呈稍高信号,7例呈等信号,4例呈稍低信号;T2WI上5例呈等信号,10例呈稍高信号;DWI上10例呈稍低信号,3例呈等信号,2例呈高低混杂信号。12例无或仅轻度水肿,3例中度水肿;11例瘤内伴囊变、坏死,7例见流空血管信号,3例颅骨破坏。MRI增强均明显强化,6例伴"脑膜尾征"。结论:HPC具有较为特征性CT、MRI征象,尤其是MRI平扫T1WI稍高信号及DWI稍低信号,具有一定的特异性,综合分析可帮助做出正确诊断。

Purpose： To investigate the value of CT and MR/in diagnosis of intracranial hemangiopericytoma （HPC）. Methods： The CT and MRI features of 15 cases with intracranial HPC proved by operation and pathology were retrospectively analyzed. Results： All the tumors were extra-axial intracranial tumors. Twelve cases were located at tentorium, 3 cases were beside venous sinus. Ten cases were irregular lobulated, 5 cases were round or oval. Six cases underwent CT plain scan and enhanced scan, all the tumors were with slight high density, 3 cases of them were with cystic necrosis; enhanced scan showed all the tumors were significantly enhanced, 2 eases were with ＂dural tail sign＂. Fifteen eases underwent plain MRI scan, DWI and enhanced scan, 4 cases of them were with slightly higher signal intensity than gray matter, 7 cases were with iso-signal intensity, 4 cases were with slightly lower signal intensity on T1WI; 5 cases showed iso-signal intensity, 10 cases showed slightly higher signal intensity on T2WI. Ten cases showed slightly lower signal intensity, 3 cases showed iso-signal intensity, 2 cases showed mixed signals intensity on DWI. Twelve cases were with no or only mild edema, 3 cases with moderate edema; 11 cases were with cystic degeneration and necrosis, 7 cases with flow void vascular signal, 3 cases with skull damage. All of the tumors were significantly enhanced, and 6 cases of them were with ＂dural tail sign＂. Conclusion： HPC had more characteristic CT and MRI features. Especially the lesion with slightly higher signal intensity on TIWI, and slightly lower signal intensity on DWI were with specificity. Correct diagnosis could be made preoperatively when the imaging features were comprehensive analyzed.