中文摘要：

目的：研究肺癌脑转移瘤在磁敏感加权图像（SWI）上的影像特点,比较其与常规MRI在脑转移瘤显示方面的不同,探讨SWI对脑转移瘤的诊断价值。方法：回顾性分析经临床证实的肺癌脑转移患者24例,其中单发8例,多发16例。所有病例均行MR常规平扫（T1WI、T2WI、T2flair）、增强扫描及SWI扫描。结果：MR常规平扫检出146个病灶,T1WI增强扫描检出221个病灶,SWI扫描检出222个病灶,其中常规序列检出出血的瘤灶35个,SWI检出出血瘤灶113个。Friedman秩和检验显示在脑转移灶检出数目方面,常规MR平扫明显少于T1WI增强扫描和SWI序列（P〈0.05）,但T1WI增强扫描与SWI序列之间无统计学差异（P〉0.05）;在出血性瘤灶数目检出方面,SWI明显优于常规序列（P〈0.05）。结论：SWI对于脑转移瘤的显示具有较高的敏感性,并在肺癌脑转移瘤内部出血显示具有一定优势。与常规MR相比,SWI能够在肺癌脑转移瘤的诊断中提供更多影像学信息。

英文摘要：

Purpose： To study the features of brain metastases from lung cancer on susceptibility weighted imaging（SWI）,and to evaluate the diagnostic value of susceptibility weighted imaging in detection of brain metastases. Methods： Twenty-four cases of brain metastasis from lung cancer were analyzed retrospectively. There were 8 cases with single lesion and 16 cases with multiple lesions. Conventional MR imaging（including pre- and post-contrasted T1 weighted imaging（T1WI）,T2 weighted imaging（T2WI） and T2 fast fluid attenuated inversion recovery）（FLAIR）and SWI were undergone in all cases. Results： More lesions were detected on post-contrasted T1WI（n=221） and SWI（n=222） than those on the pre-contrast MRI（n=146）. The difference was with statistical significance between post-contrasted T1 WI and pre-contrast MRI（P〈0.05）,and between SWI and pre-contrast MRI（P〈0.05）; there was no statistical significance between post-contrasted T1 WI and SWI in lesion detection（P〈0.05）; the number of tumors with hemorrhage detected on SWI（n=113） was significantly more than those on conventional MRI（n=35）（P〈0.05）. Conclusion： SWI is with high sensitivity to detect the brain metastasis,and it has certain advantages in detecting intratumoral small vessels and micro-hemorrhage in brain metastasis from lung cancer. SWI can provide more imaging information than conventional MRI in the diagnosis of brain metastases from lung cancer.