SWAN序列在脑白质病变中心静脉检测中的应用

目的：探讨SWAN序列在脑白质病变中心静脉检测中的应用价值。方法：20例多发性硬化及20例脑微血管性白质病变的患者，分别行FLAIR及SWAN序列MRI扫描，在FLAIR图像上对所有病变按部位（幕上侧脑室旁、幕上外围及幕下区域）进行分类，病变内中心静脉的显示情况应用SWAN序列进行评估。结果：FLAIR序列共检出622处多发性硬化白质病变及769处微血管白质病变，上述病变在SWAN序列图像上均可见。SWAN序列对中心静脉的显示率在多发性硬化及微血管白质病变中分别为78．0％和76．2％，其中多发性硬化及微血管白质病变幕上外围区中心静脉的显示率分别为74．2％和75．1％，幕上脑室旁为89．8％和91．2％，幕下白质病变为68．8％和71．5％，两组间差异无统计学意义（P〉0．05）。结论：SWAN序列是检测中心静脉的敏感方法，多发性硬化白质病变及微血管白质病变中均可见中心静脉，中心静脉的显像并非诊断多发性硬化的特异性征象。

Appliciation of detecting a central vein within white matter lesions on T2-star weighted angiography

Objective.To investigate the clinical value of detecting a central vein within white matter lesions by using T2-star weighted angiography （SWAN）. Methods： Twenty patients with multiple sclerosis （MS） and 20 patients with mi- croangiopathic white matter lesions （m-WML） underwent 1.5T MRI from December,2009 to April, 2011,including a fluid- attenuated inversion recovery sequence （FLAIR） and a Tz-star weighted angiography （SWAN）. All white matter lesions （WMLs） were identified on FLAIR and assigned to one of the following localizations., supratentorial peripheral,supratento- rial periventricular, or infratentorial. Subsequently, the presence of a central vein within these lesions was assessed on SWAN. Result： A total of 622 MS-WMLs and 769 m-WMLs were identified on FLAIR,all of which could also be visualized on SWAN. A central vein was detectable in 78% of the MS-WMLs and in 76.2% of the m-WMLs （in 74.2% and 75.1% of the peripheral,in 89.8% and 91.2% of the periventricular,and in 68.8% and 71.5% of the infratentorial MS-WMLs and m-WMLs, respectively） ,there was no significant difference. With regard to the supratentorial peripheral lesions, significant- ly more m-WMLs showed a central vein compared to the MS-WMLs. Conclusion： SWAN sequence may be an optimization method on detecting central vein. A central vein could be showed in both m-WML and MS-WMLs. The detection of a central vein within a WML should not be considered a specific finding for MS.