磁敏感加权成像对弥漫性轴索损伤的诊断价值

Diagnostic value of magnetic susceptibility weighted imaging in diffuse axonal injury

目的探讨磁敏感加权成像（SWI）对弥漫性轴索损伤（DAI）的诊断价值及与临床、预后的关系。方法对20例临床确诊为DAI的脑外伤患者行3．0TMR常规序列扫描f包括T1W1、T2WI、液体衰减反转恢复（FLAIR）序列]及SWI序列扫描，格拉斯哥评分（GCS）为3．0～5．0分者8例，6．0～8．0分者4例，9．0～12．0分者8例。分别为伤后3h至20d内行MR扫描并加扫SWI序列，分别测量所有患者在MR常规序列扫描和SWI的病灶数量及体积。常规扫描序列和SWI检出病灶数量的比较采用Mann—WhitneyU检验，病灶体积比较采用配对t检验，观察有无差异；SWI检查与临床、预后采用Pearson相关分析。结果DAI病灶在SWI表现为：脑内皮髓质交界区、脑白质、培底节、胼胝体、脑干、小脑等区域散在大小不等的点状、串珠状、斑片状、条索状显著低信号灶（病灶直径〈2．0cm），病灶分布呈多灶性，大小不均，边界清晰。MRI常规序列扫描共发现78个病灶；SWI序列共发现424个病灶，SWI序列发现病灶数量明显多于常规MR扫描（U=-15．447，P〈0．01）；分别测量MRI常规序列扫描和SWI序列发现的病灶体积为19340mm^3和38042mm^2，两者比较差异有统计学意义（t=5．870，P〈0．01）。其中SWI序列显示的病灶数量和病灶体积与GCS评分之间呈明显的负相关，相关系数分别为-0．802、-0．767，P值均〈0．01。结论SWI序列可以在DAI患者中发现更多的出血病灶及较常规扫描明显扩大的病灶体积，并且病灶的体积和数量与GCS评分密切相天，对DAI的诊断及判断患者的预后有很高的价值。

Objective To study the diagnostic value of susceptibility weighted imaging （SWI） in diffuse axonal injury （DAI） and investigate the relationship between SWI and clinical prognosis. Methods Twenty patients （ 15 males and 5 females） with DAI were included in this study. Routine sequences （T1WI, T2WI and FLAIR） and SWI were performed on a 3.0 T MRI scanner. There were 8 cases whose Glasgow score scale （GCS） ranged from 3.0 to 5.0, 4 cases from 6. 0 to 8.0 and 8 from 9. 0 to 12.0. The interval time between injury and examination were from 3 hours to 20 days. The number and volume of lesions observed on SWI and routine sequence were compared using Mann-Whitney U-test and paired t-test. Pearson con＇elation was used to analyze the relationship between the number and volume of all lesions and GCS. Results The lesions showed punetate, beaded, patchy and cord-like hypointense signal with various size on SWI （lesion diameter 〈2. 0 era）. Distribution of lesions was muhifocal with clear boundary. Routine MRI scan fi）und a total of 78 lesions, while SWI sequence detected 424 lesions. The number of the lesions found （m SWI was more than that on conventional MRI （ U = - 15.447 ,P 〈0. 01 ）. The total volume of the lesions measured on routine MRI and SWI were 19 340 mm3 and 38 042 mm3, respectively. The total volume measured on SWI was more than that on routine MR （t = 5. 870 ,P 〈0.01 ）. The number and volume of all lesions were negatively correlated with GCS （ r = - 0. 802, - 0. 767, P 〈 0. 01 ） . Conclusion SWI sequence could find more bleeding lesions than the routine MRI sequences. The number and the volume of the lesions were closely related to GCS. SWI showed high value in the diagnosis and prediction of the prognosis of DAI.