血流通过梯度磁场和射频场产生的信号变化可使血管区别于周围的静止组织而成像。ＭＲ血管成像的信号可通过二种标准技术采集，即相位对比（ＰＣ）法和时间飞越（ＴＯＦ）法，使用或者不用Ｇｄ－ＤＴＰＡ增强。本文报道我们早期的６６例ＴＯＦ法ＭＲＡ的经验，探讨了其临床价值与限度。结果表明ＭＲＡ作为无创性方法用于评价正常脑血管解剖及变异、动静脉畸形、动脉瘤、动脉硬化和闭塞、肿瘤血管和血管移位及包埋、硬脑膜窦侵犯等，可提供更多的诊断信息。 Changes in blood flow through the gradient magnetic field and the changes in the RF field can cause blood vessels to differentiate from surrounding static tissue. Signals for MR angiography can be acquired by two standard techniques, the phase contrast (PC) method and the time-of-flight (TOF) method, with or without Gd-DTPA enhancement. This article reports our earlier 66 cases of TOF MRA experience, discusses its clinical value and limits. The results show that MRA as a noninvasive method for the evaluation of normal cerebral vascular anatomy and variability, arteriovenous malformations, aneurysms, atherosclerosis and occlusion, tumor vessels and vascular displacement and embedding, dural sinus invasion, etc., can provide more Diagnostic information.