脊柱髓外膜内肿瘤的MR成像

分析２８例经手术证实的髓外膜内肿瘤的ＭＲＩ表现，其中神经鞘瘤１７例，神经纤维瘤４例，脊膜瘤５例，其它肿瘤２例，ＭＲＩ对髓外膜内肿瘤定位准确率达９６．４％。ＭＲＩ ＳＥ序列Ｔ２加权像和Ｇｄ－ＤＴＰＡ增强扫描图像中病灶中心二是鉴别神经源性肿瘤和脊膜瘤的依据，但不能鉴别神经鞘瘤和神经纤维瘤。

MRI OF INTRADURAL EXTRAMEDULLARY TUMORS

Twenty-eight patients with intradural extramedullary tumors were examined with magnetic resonance (MR) imaging performed using a 0.5T magnet ,surface coil and spin-echo pulse sequences .Gadoliniun-DTPA in a concentration of 0.1 mmol/kg was injected intravenously in 14/17 patients .All tumors were verified surgically :seventeen schwannomas ,five meningiomas ,four neurofibromas ,one lipoma and one dermoid cyst were found . In all 17 patients with schwannoma ,15 tumors had markedly increased signal intensity compared to spinal cord on T 2 weighted image (T 2WI),and 10/15 tumors possessed a central lower signal area . All five meningiomas had homogenous iso-or hyperintense compared to spinal cord on T 2WI.On Gd-DTPA enhanced MR imaging , meningiomas appeared markedly homogenous contrasted enhancement , but schwannomas had decreased signal intensity in the center of enhanced tumors . Results showed that these decrease signal intensity in the center of the high sigmal tumors on T 2WI and Gd-DTPA enhanced MR imaging may be used to distinguish schwannomas from meningiomas .