椎管内黏液乳头型室管膜瘤的MRI征象分析

The analysis of MRI appearance of intraspinal myxopapillary ependymoma

目的:探讨椎管内黏液乳头型室管膜瘤(MPE)的MRI征象,提高本病术前影像诊断水平。方法:回顾性分析本院经手术病理证实且影像资料及手术记录完整的15例MPE的临床资料及影像表现。结果:15例MPE均为单发病灶,8例位于腰2椎体附近。15例肿瘤呈中心性纵向生长,平均长径为(5.14±2.92)cm。13例表现为规则的长椭圆形,1例表现为短椭圆形,1例形态不规则,对椎管后方骨质压迫、吸收呈“扇贝样”改变,但未累及椎间孔。12例肿瘤与脊髓圆锥或马尾终丝分界不清,3例对脊髓圆锥或马尾终丝推移。T1WI平扫14例呈等信号(参照脊髓灰质),1例呈低信号。T2WI平扫14例为高信号,1例为完全低信号,14例肿瘤内部或边缘可见点状、条状及斑片状低信号,有8例肿瘤头端或尾端表现为“帽征”,且全部为马尾终丝区的肿瘤。5例肿瘤内部可见囊变,2例尾端囊变。T1WI增强15例肿瘤实体均明显强化,10例肿瘤表现为“蜂窝状”强化,1例肿瘤T2WI显示为完全低信号,增强后环形强化。结论:椎管内MPE在MRI上具有一定的特征性,结合临床资料,能提高术前诊断的准确性。

Objective:To investigate the MRI signs of intraspinal myxopapillary ependymoma(MPE)and improve the preoperative imaging diagnosis of this disease.Methods:We retrospectively analyzed the clinical data and imaging findings of 15 cases of MPE,which were confirmed by pathological diagnosis with complete imaging data and surgical records.Results:All 15 cases of MPE were single lesion,among which 8 cases were located near the second lumbar vertebral body.All the tumors showed central growing longitudinally,with an average length diameter of(5.14±2.92)cm.The shape of tumor were long epllitic in 13 cases,and 1 case was short oval.Another 1 case was irregular compressing the posterior bone of the spinal canal with a fan shaped change,but this tumor did not involve the intervertebral foramen.The boundary between the tumor and conus medullaris and cauda equina was not clear in 12 cases.The spinal cord conus or cauda equina filum was displaced due to tumor compression in 3 cases.On T1WI scan,14 tumors showed isointense(reference to gray matter),and 1 case showed low signal.On T2WI scan,14 tumors showed high signal,1 case showed low signal,14 cases showed spots,strips or patches of low signal,and 8 cases with“cap like sign”all of which were in the terminal filaments of cauda equina.Five cases showed cystic changes inside the tumor,and 2 cases had cystic changes at the tail.The enhanced MRI showed tumors in 15 cases were significantly enhanced,and that 10 cases showed honeycomb enhancement.In addition,1 case showed low signal on T2WI,and annular enhancement after T1WI enhancement.Conclusion:MRI features of intraspinal MPE were specific in a certain,and might improve the accuracy of preoperative diagnosis by combining clinical data.