低场MR增强扫描及FLAIR序列对脑转移瘤诊断的评价

目的 :探讨低场MR增强扫描与FLAIR序列在脑转移瘤诊断中的价值。方法 :搜集 2 9例脑转移瘤患者 ,使用 0 .2 3TMR扫描仪 ,对比分析常规T1 WI、T2 WI、增强扫描及FLAIR序列在检出转移瘤和明确转移瘤边界方面的敏感性。结果 :增强扫描对转移瘤检出以及明确转移瘤边界的敏感性高于FLAIR、T2 WI及T1 WI ,经统计分析其差异有极显著性意义 (P <0 .0 1)。对于直径 <1.0cm的软脑膜转移瘤及皮质近蛛网膜下腔处转移瘤的检出及明确肿瘤边界的敏感性FLAIR高于常规T2 WI ,差异有显著性意义 (P <0 .0 5 ) ;对于直径≥ 1.0cm的软脑膜转移瘤、皮质近蛛网膜下腔处转移瘤及深部脑转移瘤 ,FLAIR与常规T2 WI检查差异无显著性意义 (P >0 .0 5 )。结论 :脑转移瘤的低场MRI诊断 ,增强扫描是最有价值的检查方式 ,而FLAIR可取代常规T2 WI。

Contrast-enhanced imaging and FLAIR sequence on Iow field MR in diagnosing cerebral metastases

Objective:To study the value of contrast enhanced T 1 weighted images and FLAIR sequence on low field (0.23T) MR scanner in diagnosing cerebral metastases.Methods:The following was analyzed:the sensitivity of routine T 1 weighted images,T 2 weighted images,contrast enhanced T 1 weighted images and FLAIR images in demonstrating the cerebral metastases and their boundaries in 29 patients.Results:Contrast enhanced T 1 weighted imaging was proved to be most sensitive in demonstrating the numbers and boundaries of the cerebral metastases among the scanning techniques.The difference was significant between contrast enhanced T 1 weighted images and FLAIR images,routine T 1 weighted images and routine T 2 weighted images( P <0.01).FLAIR images were more sensitive than routine T 2 weighted images in demonstrating the numbers and boundaries of the cerebral metastases which were located in the leptomeninges or cortex adjacent to subarachnoid space and their sizes were larger than 1.0cm( P <0.05),but the difference was not significant to the metastases which sizes were smaller than 1.0cm and all that located in central brain tissues( P >0.05).Conclusion:Contrast enhanced T 1 weighted image is the best technique in diagnosing cerebral metastases.FLAIR sequence can substitute routine T 2 weighted images.