脑实质内室管膜瘤的影像学诊断

摘要

目的：探讨脑实质内室管膜瘤的 CT 及 MRI 影像特点。方法手术切除并经病理检查证实的脑实质内室管膜瘤25例（室管膜瘤11例、间变性室管膜瘤14例），术前行 CT 和（或）MRI 检查，对其检查结果进行分析。结果 CT 和（或）MRI 检查显示24例患者的病灶位置与脑室关系密切，脑室呈受压变形改变；1例患者的病灶位于左侧顶枕叶，仅累及灰质。14例行 CT 检查，8例表现为颅内不均匀混杂密度的囊实性肿块，6例瘤内、瘤旁出现钙化。20例患者行 MRI 检查，肿瘤实体部分呈长 T1、等稍长 T2混杂信号，其中13例的病灶边缘出现囊肿，Flair 序列显示囊内呈稍高信号，增强扫描肿瘤实性成分边缘呈厚壁样或花环样强化，囊壁强化；其中9例同时行磁共振波谱（MRS）检查，均表现为 Cho 峰增高、NAA 峰降低，出现高耸 Lip 峰；3例间变性室管膜瘤患者同时行酰氨质子转移（APT）MRI 成像检查，瘤核心 APT 值分别为2．96、3．76、3．48。结论脑实质内室管膜瘤的影像学表现有一定特征性，如脑室附近出现混杂密度／信号肿块，肿块内部多不规则坏死、钙化，边缘可见囊肿，MRS 示 Cho 峰明显增高、NAA 峰明显降低，出现高耸 Lip 峰，瘤核心 APT 值增高对预测肿瘤级别有一定帮助。%Objective To investigate the features of X-ray computed tomography (CT)and magnetic resonance ima-ging (MRI)of cerebral parenchyma ependymoma.Methods Twenty-five patients with cerebral parenchyma ependymoma which were confirmed by pathological examination after surgical resection,including 11 ependymomas and 14 anaplastic ependymomas were selected.The CT and MRI features of these patients were analyzed.Results The lesion locations of 24 cases were closely related to adjacent ventricles which were compressive deformation,and 1 case was not,it located in the left parietal-occipital lobe.Fourteen patients underwent CT scan,heterogeneous mass was found in 8 cases,and peritu-moral calcification or intratumoral calcification were found in 6 cases.In the 20 patients after MRI,the solid part of the tumors showed hypointense on T1 WI,isointense or slight hyperintense on T2 WI,13 of which showed cystic degeneration in periphery regions of the lesions.And the intracapsular part showed slight hyperintense on Flair.There was remarkable en-hancement in the solid part and the peripheral cystic wall.Decreased NAA and increased Cho and Lip were found in 9 ca-ses who underwent magnetic resonance spectrum (MRS).Three cases of anaplastic ependymomas performed amide proton transfer (APT)imaging,the APT rate was 2.96,3.76 and 3.48,respectively.Conclusions Cerebral parenchyma ependymoma has some characteristic imaging features,such as,a heterogeneous intensity tumor with central necrosis,cal-cification and peripheral cystic change,decreased NAA peak and increased Cho and Lip peak on MRS.Meanwhile,the in-creased APT of tumor core could help to predict the tumor grade.