三维增强MR血管成像在常见脑血管病诊断中的价值

目的:评价三维增强磁共振血管造影(3D CE-MRA)对常见脑血管病的诊断及其临床应用价值.方法:头颅血管3D CE-MRA检查907例,226例同期行DSA检查.常规横断面T2加权像扫描,发现病变时加扫横断面T1加权及冠状面T2加权像;3D CE-MRA用钆对比剂(Gd-DTPA) 0.2 mmol/kg,注射速率3 ml/s,行增强前、增强后动脉期及静脉期3次扫描,图像减影后至工作站上三维重建.结果:(1)脑动脉狭窄或闭塞者244例,其中81例有DSA对照,82.5%(80/97)狭窄或闭塞的3D CE-MRA与DSA一致,17.5%(17/97)的3D CE-MRA所示的动脉狭窄较DSA程度重,约重10个百分点.(2)临床高度怀疑脑动脉瘤者118均有同期DSA对照,两者共诊断84例98个动脉瘤,3D CE-MRA对颅内动脉瘤的敏感性为96.1%(98/102),特异性为76.7%,准确性为91.7%.(3)脑动静脉畸形35例,27例有DSA对照,3D CE-MRA对供血动脉的显示率为81.2%(56/69),对引流静脉的显示率为87.2%(41/47),3D CE-MRA结合MRI对异常血管团的定位及立体显示优于DSA,在显示某些细节上不如DSA.结论:3D CE-MRA能无创、快速、有效诊断常见脑血管病,一次检查即能为临床提供较为全面的信息,可作为脑血管病患者的首选诊断方法.

Diagnostic value of 3D contrast-enhanced MR angiography for common cerebrovascular diseases

Objective: To assess the clinical value of three-dimensional dynamic contrast-enhanced MR angiography (3D CE-MRA) in the diagnosis of common cerebrovascular diseases. Methods: Nine hundred and seven patients underwent cerebral 3D CE-MRA and among them 226 patients also received DSA contemporaneously. Transverse T_2-weighted imaging was used in all patients firstly, and transverse T_1-weighted and coronal T_2-weighted imaging were used if any pathological change was suspected. A three-dimensional fast low angle shot (3D FLASH) was used for 3D CE-MRA with Gd-DTPA (0.2 mmol/kg). The source images were subtracted and transferred to computer workstation using 3D reconstruction. Results: Cerebral artery stenosis or occlusion was found in 244 patients, among whom 81 patients also received DSA, with the accordance rate between 3D CE-MRA and DSA being 82.5% (80/97). The artery stenosis appeared more severe with 3D CE-MRA than with DSA in 17(17.5%) patients. One hundred and eighteen patients highly suspected as having cerebral aneurysms underwent 3D CE-MRA and DSA contemporaneously, and 98 aneurysms in 84 patients were diagnosed with both examinations. The sensitivity of 3D CE-MRA was 96.1%, the specificity 76.7%, and the accuracy 91.7%. Twenty seven of 35 patients with cerebral arteriovenous malformations underwent 3D CE-MRA and DSA contemporaneously. The sensitivity of 3D CE-MRA was 81.2%(56/69) in depicting feeding arteries, and 87.2%(41/47) in depicting draining veins. 3D CE-MRA combined with MRI was better than DSA in localization and 3D demonstration of the nidus, but was inferior in demonstrating some details. Conclusion: 3D CE-MRA, a fast non-invasive and effective technique, can accurately diagnose common cerebrovascular diseases. It can provide overall information for treatment planning and can be used as the first choice for the diagnosis of cerebrovascular diseases.