脑梗死FLAIR高信号血管征的影响因素研究现状

Factors influencing hyperintense vessel sign on FLAIR sequence in cerebral infarction: current study status

高信号血管征(HVS)定义为液体衰减反转恢复(FLAIR)序列上大脑半球沿脑沟或脑表面分布相对于脑灰质的点状、线状或管状的高强度信号,可用于诊断血管狭窄或闭塞,预测缺血半暗带、评价病人临床预后。HVS具有时间依赖性,常见于急性脑梗死早期阶段。动脉狭窄程度及部位可不同程度地减慢供血动脉血流流速,随着血流流速减慢,HVS逐渐明显。脑侧支循环级别及临床其他相关因素决定侧支循环流速,而脑侧支循环缓慢逆流也是影响HVS成像的主要因素。MRI参数的改变也会影响FLAIR序列上HVS的显示。

Hyperintense vessel sign（HVS） is defined as focal, serpentine, or tubular hyperintensity relative to gray matter in the subarachnoid space or extending into the parenchyma on fluid-attenuated inversion recovery images（FLAIR）.HVS could be used for diagnosis of vascular stenosis or occlusion, prediction of ischemic penumbra, and evaluation of clinical outcome. HVS is time-dependent sign, often occurring in early stage of acute cerebral infarction. The degree or location of the artery stenosis can slowdown cerebral artery flow velocity in various degrees. When flow velocity decreases into a certain range, the HVS becomes prominent. The level of collateral circulation and other clinical related factors can affect collateral flow velocity, and the slow retrograde flow is also another important factor affecting HVS. MRI scanning parameters can affect the presentation of HVS on FLAIR.