ADC值在鉴别血管外皮细胞瘤与脑膜瘤中的应用

Application of ADC Values in Differentiating Hemangiopericytomas from Meningiomas

目的:回顾性总结颅内血管外皮细胞瘤(HPC)的影像学特点,探究弥散加权成像及ADC值在鉴别血管外皮细胞瘤及不同亚型脑膜瘤中的诊断价值。方法:回顾性分析从2008年12月到2014年8月期间我院收治的15例颅内血管外皮细胞瘤及126例脑膜瘤,测量肿瘤实性部分及对侧正常白质ADC值,对肿瘤组织平均ADC值(m ADC)及标化ADC值(NADC)即肿瘤组织ADC/对侧正常白质ADC进行统计学分析。结果:本组HPC病例的m ADC及NADC值分别高于上皮型、纤维型、过渡型、砂砾型、非典型及间变型脑膜瘤且其差值分别具有统计学意义(P<0.05),而HPC与血管瘤型脑膜瘤之间的m ADC及NADC差值无统计学意义(P>0.05)。结论:ADC值在血管外皮细胞瘤与脑膜瘤的鉴别诊断,尤其是与恶性脑膜瘤的鉴别中有着重要的临床意义。

Purpose： This retrospective study aimed to summarize the imaging features of intracranial hemangiopericytoma（HPC）, to determine the value of apparent diffusion coefficient（ADC） values in differentiating hemangiopericytoma from meningiomas and to improve the diagnostic efficacy preoperatively. Methods： Pathologically proved HPC（n=15） and fibroblastic（n=25）, meningothelial（n=26）, angiomatous（n = 19）, psammomatous（n=12）, transitional（n=13）, atypical（n =21） or anaplastic（n=10） meningiomas（n=126 in total） between December 2008 and October 2014 were retrospectively reviewed. The ADC values were measured in the solid part of the lesions and the normalized ADC（NADC） ratios were calculated using the formula NADC = ADC of the tumor/ADC of the contralateral normal white matter. Results：In the 15 cases, 12 tended to be lobulated in shape and 12 appeared as cystic change and necrosis. Dural tail sign and vascular flow void signal could be seen in 8 and 12 cases respectively. In 7 cases, the tumors were with narrow dural base. On contrasted images, the solid component of the tumors showed with marked enhancement. The mean ADC（m ADC） and NADC values were higher in HPC than that in fibroblastic, meningothelial, psammomatous, transitional, atypical or anaplastic meningiomas respectively, while the m ADC and NADC values were also with statistical significant difference between HPC and all subgroups except angiomatous meningiomas（P〈0.05）. The m ADC values and NADC ratios were not with significant difference between HPC and angiomatous tumors（P〉0.05）. Conclusion： Certain MRI characteristics could be assessed in intracranial HPC. HPC group displays different ADC values from meningioma subgroups except angiomatous group. Thus, ADC values may provide a useful supplement in differentiating hemangiopericytoma from meningiomas especially the malignant subtypes.