中文摘要：

目的探讨3．0TMR不同序列对肺癌脑转移的诊断价值。方法回顾性分析本院经病理确诊为肺癌并经临床诊断为脑转移瘤的¨例患者，所有病例均行常规T1WI、T2WI、T2FLAIR、DWI、T1WI增强MR检查；其中4例行DTI检查；3例行SWI检查。对转移瘤的部位、信号特点、不同序列病灶的检出率、转移瘤与止常脑实质的rADC值等进行分析。结果转移瘤好发于灰白质交界处，其中幕上73．5%，幕下24．7％；强化方式以结节状（80．7％）和环状（16．3％）为主。与其他序列相比T，wI增强检出率最高。转移瘤实质部分rADC值为（126．5±28．2）％，水肿部分的rADC值为（159．3±42．1）％，与正常侧脑实质rADC值差异有统计学意义（P〈0．05）。3例SWI所显示脑部放疗转移瘤低信号区均较增强MRI范围小。4例转移瘤区的白质纤维束有移位、浸涧。结论3．0TMR对肺癌腩及脑膜转移的检出有一定的优越性，T1WI增强扫描是最佳序列，弥散、弥散张量及磁敏感成像有助于脑转移瘤的定性诊断及疗效评估。

英文摘要：

Objective To study the value of different MR sequences in monitoring intracranial metastases of lung cancer using 3.0 T MR scanner. Methods 11 patients with brain metastases of primary lung cancer underwent MRI examination including T1WI, T2WI, T2 FLAIR, DWI, contrast--enhanced T1WI sequences. Of them, 4 cases underwent DTI scan, 3 patients underwent SWI scan. The location of metastatic tumors, signal characteristics, the detecting rate of tumors with different sequences, the rADC value of metastatic tumor and normal brain were analysed. Results The metastatic tumors of the brain most located in the junctional zone of cerebral gray white matter, 73.5% located in supratentorial region and 24.7% in infratentorial region. The enhanced patterns of metastases at contrast--enhanced MR imaging were nodular [80.7 % } and ring{ 16.3 %1. Compared with other sequences,T2WI enhancement had the highest detecting rate. The rADC value of metastatic substantial part, edema part, normal contralateral brain were[ 126.5 ± 28.2）%, （159.3 ± 42.1）%, 100 % respectively and there was statistically significance difference between them （P〈 0. 05 ）. 3 cases on SWI,the lesions showed relatively low signal areas which were smaller than those in enhanced MRI images. 4 eases on DTI, the white matter tracts of metastatic region displayed shift and infiltration. Conclusion High field MR has advantages for the detection of intracranial metastases of lung cancer. T1WI enhancement is best sequence to find metastases. DWI, DTI and SWI are helpful for the diagnosis and evaluation of brain metastases.