枕骨大孔区肿瘤的低场MRI表现

目的探讨枕骨大孔区肿瘤的低场磁共振成像（MRI）表现。方法回顾性分析19例经手术病理或临床证实的枕骨大孔区肿瘤的低场MRI资料。结果 19例中,脑膜瘤6例,表现为T1WI、T2WI均呈等或略低信号,增强扫描多明显均匀强化,可见脑膜尾征;神经鞘瘤3例,均位于延颈髓交界区,有沿颈1、2椎间孔向外生长趋势,除囊变外较明显强化;室管膜瘤3例,均伴囊变,实性部分不均匀中度强化;表皮样囊肿1例,主要位于小脑蚓部,向下达椎管内,类似水样信号,增强无强化;骨转移6例,表现为斜坡下半部、枕骨鳞部前缘、寰椎等T1WI多低T2WI多高信号影。结论低场MRI对颅枕骨大孔区肿瘤的诊断具有重要价值。

Low Field MRI Performance of the Tumors in the Region of Foramen Magnum

Objective To explore the performance of foramen magnum tumors in low field MRI.Methods The datas of 19 cases of foramen magnum tumors which were confirmed pathologically or clinically in low field MRI were retrospectively analyzed.Results Among the 19 cases,6 cases were meningioma,which showed T1WI,T2WI equal or slightly lower signal,enhancement was even more homogeneously enhanced,dural tail signs were visible;3 cases were schwannoma,which located at the junction of the medulla oblongata and spinal cord,along the neck 1,2 intervertebral foramen outward growth trend,were more obvious enhanced in addition to cystic outside;3 cases were ependymoma,associated with cystic,showed uneven moderate enhancement in the part of solid part;1 case was epidermoid cyst,located mainly in the cerebellar vermis,similar to the water signal,no enhancement.Bone metastasis in 6 cases,which showed low T1WI and high T2WI signal intensity in lower slopes,the leading edge of the occipital squama,the atlas and other regions.Conclusion Low field MRI has important value in the diagnosis of tumors of the foramen magnum region.