椎管内微小占位性病变的MRI诊断

目的:研究椎管内微小占位性病变的MRI特征及其对病变定性、定位诊断的意义。材料与方法:24例椎管内微小占位性病变患者(男12例,女12例,年龄23～67岁,平均29.1岁)均经PHILIPS 1.0NT型MR仪行常规T_1WI、T_2WI磁共振成像,其中6例又经Gd-DTPA增强扫描。全部病例的椎管内占位病变均经病理证实,并对其MRI表现进行了回顾性分析。结果:24例的病变经病理证实,18例为胚胎源性肿瘤(10例表皮样囊肿,4例皮样囊肿,4例畸胎瘤),4例为神经源性肿瘤(3例神经鞘瘤,1例神经纤维瘤),以及脊膜瘤与脂肪瘤各1例。各种占位性病变的MRI表现随其不同的组织学来源而有很大差别。表皮样囊肿多为均质长T_1长T_2信号。皮样囊肿以短T_1,长T_2信号为主。畸胎瘤呈混杂信号。神经鞘瘤为T_1WI低信号、T_2WI高信号,Gd-DTPA增强扫描后,囊壁均匀强化,偶见强化附壁结节。神经纤维瘤呈均质长T_1、长T_2信号,Gd-DTPA增强扫描后,病灶呈异常对比增强。脊膜瘤呈长T_1、稍长T_2信号,Gd-DTPA增强扫描后,病灶呈异常对比强化,并见局部硬脊膜增厚强化而形成的硬膜尾征。结论:各种病变的MRI表现随其组织学来源不同而有明显差异,它们在椎管内微小占位性病变的定性、定位诊断中起着重要作用,其诊断准确性优于X线椎管造影与CT。

Diagnosis of Intraspinal Canal Small Space-Occupying Lesions with MR Imaging

Purpose: To investigate MRI features of intraspinal small masses of spinal canal and its role in the qualitative and located diagnosis of these lesions. Materials and Methods: Twenty-four patients (12 men, 12women; aged 23 - 67years, mean age, 29 years)with intraspinal small masses of spinal canal underwent conventional T1W, T2W MR imaging in diggital, axial and coronal planes using a 1. 0 NT MR system; 6 patients underwent additional Gd - DTPA enhancement scan and 1 patient underwent additional fat suppressed MR imaging . MRI findings of various masses those were proved by postoperative pathology were analyzed retospectively. Results: Of all patients, 18 patients with embryonal tumors(10 epidermoid cyst, 4 dermoid cyst, 4 teratoma), 4 patient with neurogenic tumors (3 neurolemmoma, 1 neurofibroma), 1 patient with meningioma, and 1 patient with lipoma were pathologically proven. MRI findings of various masses were significantly different with their histologic origin. For example, epidermoid cyst was mostly hypointensity on T1WI, hyperintensiiy on T2WI; dermoid cyst was predominantly hyperintensity on T1WI and T2WI ; teratoma was heterogenous intensity; neurolemmoma hypointensity on T1WI, hyperintensity on T2WI, following Gd-DTPA enhancement scan , the cystic wall was homogeneous enhancement with occasional intramural nodules; neurofibroma was homogeneous hypointensity on T1WI and slightly hyperintensity on T2WI, following Gd - DTPA enhancement scan , the lesion was abnormal contrast enhancement; meningioma was hypointensity on T1WI and slightly hyperintensity on T2WI, following Gd - DTPA enhancement sean, the lesoon was abnormal contrast enhancement with local dura mater tair sign what was formed from dural thickening enhancement. Conclusion: As have been mentioned above, MRI findings of various masses were significantly different with their histologic origin , therefore, they have important roles in the qualitative and located diagnosis of intraspinai small space-occupying lesions of spinal canal and are obviously superior to spinal canal Roentgenography or CT examination.