对比T2FLAIR序列与增强T1WI序列在诊断脑转移瘤过程中的诊断价值

目的：比较增强T1WI及增强T2FLAIR两种序列对脑转移瘤的诊断价值。方法：回顾分析本院2008年9月～2010年3月34例经临床和影像检查确诊为脑转移瘤的患者资料,所有病例均行常规MRI平扫及SET1WI和T2FLAIR增强扫描,比较两种序列上转移瘤的数目、大小和部位以及转移瘤的强化显著性、病变强化区的边界等,并分析两者间偏差的原因。结果：34个病例,MRI平扫共检出129个病灶,增强T1WI发现194个病灶,而增强后T2WI FLAIR共发现185个病灶,4例增强后T2FLAIR较增强后T1WI显示的病灶多,6例增强后T2FLAIR显示的病灶少于增强后T1WI,25例两者显示的病灶相同,增强后T1WI因为脑浅表层血管混淆而漏诊误诊7个病灶,在对比增强后T2FLAIR均可明确诊断。大多数转移瘤在T1WI的强化程度高于T2FLAIR序列。转移瘤的肿瘤与灰质、肿瘤与白质的CR（对比率）以FLAIR序列为高,而转移瘤的肿瘤与灰质、肿瘤与白质的CNR（对比噪声比）以T1WI为高,两者有显著性差异（P〈0.01）。结论：增强后T2FLAIR序列可以有效显示脑转移灶,很好地鉴别大脑浅表部位的血管和转移瘤,增强T1WI序列能更明显地显示转移瘤的强化,两者同时使用,可以提高转移瘤的检出率与诊断准确性。

Comparison of the value of contrast T1 WI and contrast-enhancement T2 FLAIR in diagnosing intracranial metastases

Objective:To evaluate the diagnostic value of contrast-enhanced T1WI and contrast-enhanced T2FLAIR sequences in detection of brain metastases.Methods:34 cases(Sep,2008-Mar,2010) with brain metastases were enrolled in this study.Pre-contrast and post-contrast(SE T1WI,T2FLAIR) MRI in all patients were acquired.The number,size,position,the presence of abnormal contrast-enhancement and the edge of brain metastases were analyzed retrospectively.The difference between the two sequences was analized too.Results:Am...