肺癌脊髓内转移的MRI诊断

目的：探讨肺癌脊髓内转移（ISCM）的MRI表现特征及病理机制。方法：对3例经手术病理证实及4例临床确诊的肺癌脊髓内转移的MRI表现进行回顾性分析。全部病例均行MRI平扫及钆喷替酸葡甲胺（Gd-DTPA）增强扫描。结果：7例转移瘤均为单发，3例位于胸段，4例位于脊髓圆锥部。主要MRI表现：肿瘤均位于脊髓中央，T1WI1例呈低信号，6例呈等信号，T2WI全部为高信号，病灶上下方髓内可见水肿2例，空洞3例；平扫肿瘤边界模糊不清，增强扫描均呈明显强化，其中3例呈不均匀强化，3例呈环形强化，1例呈结节样强化，增强后肿瘤边界显示十分清楚。结论：肺癌脊骨转移的MRI表现常为明显强化的髓内肿物，但其缺乏特征性，定性诊断需结合临床资料综合分析。

The MRI diagnosis of lung cancer intramedullary spinal cord metastasis

Objective To discuss the MRI features and pathogenic mechanisms of lung cancer intramedullary spinal cord metastasis (ISCM). Methods Four cases with clinically and 3 cases pathologically proved lung cancer ISCM were analyzed retrospectively. Turbo spin-echo sequence T 1 and T 2 weighted images were acquired in all patients. T 1 weighted images were obtained after intravenous administration of Gd-DTPA in all patients. Results A total of 7 ISCM were displayed by MR studies. The tumor occurred in thoracic cord (3/7) and in medullary cone (4/7). The tumor involved the central aspect of the cord. The lung cancer ISCM showed hypointensity (n=1) or isointensity (n=6) on T 1WI and hyperintensity on T 2WI. The extensive cord enlargement with cyst formation or syringomyelia was common. On contrast study, all tumors showed marked homogenous enhancement with clear borders. Conclusion The lung cancer ISCM usually presented as solitary lesions with marked contrast enhancement. The extensive cord enlargement was common in all patients. Because of the limitation in the evaluation of lung cancer ISCM on MRI, definite diagnosis of lung cancer ISCM depended on combination of clinical and MRI data.