Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
Cerebrovasc Dis. 2010 Aug;30(3):277-84. doi: 10.1159/000319070. Epub 2010 Jul 24.
In patients with carotid artery stenosis, ipsilateral hemodynamic compromise is associated with an increased risk of stroke. It is unclear which factors determine cerebral perfusion. We studied the effect of both the degree of the stenosis and the collateral circulation via the circle of Willis (CoW) on cerebral perfusion in patients with symptomatic carotid artery stenosis.
In 88 patients with unilateral symptomatic carotid artery stenosis of > or =50%, CT perfusion was used to measure the relative cerebral blood volume (rCBV), the difference in mean transit time (DeltaMTT) and the relative cerebral blood flow (rCBF). CT angiography was used to measure the degree of carotid stenosis and to assess the configuration of the CoW. Differences in mean rCBF, rCBV and DeltaMTT between patients with a carotid stenosis of < or =69, 70-79, 80-89 and 90-99%, and between patients with a complete and those with an incomplete CoW were determined by analysis of covariance.
The ipsilateral rCBF showed a gradual decrease with increasing severity of carotid stenosis (1.09 +/- 0.06, 0.93 +/- 0.06, 0.90 +/- 0.04 and 0.83 +/- 0.04 ml/100 g/min, respectively; p = 0.005), and the DeltaMTT showed a gradual increase (-0.02 +/- 0.33, 0.16 +/- 0.34, 1.08 +/- 0.22 and 1.47 +/- 0.20 s, respectively; p < 0.001). The rCBV was not related to the severity of stenosis. No relation was found between the configuration of the CoW and the cerebral perfusion parameters.
Cerebral perfusion is inversely related to the degree of stenosis in patients with symptomatic carotid artery stenosis. A relation between the configuration of the CoW and cerebral perfusion was not detected, suggesting that other collateral pathways play an important role.
在颈动脉狭窄患者中，同侧血液动力学受损与中风风险增加相关。目前尚不清楚哪些因素决定了脑灌注。我们研究了狭窄程度和通过 Willis 环（CoW）的侧支循环对症状性颈动脉狭窄患者脑灌注的影响。
在 88 例单侧症状性颈动脉狭窄≥50%的患者中，使用 CT 灌注测量相对脑血容量（rCBV）、平均通过时间差（DeltaMTT）和相对脑血流（rCBF）。使用 CT 血管造影测量颈动脉狭窄程度，并评估 CoW 的形态。通过协方差分析确定颈动脉狭窄<或=69%、70-79%、80-89%和 90-99%患者之间以及完全性和不完全性 CoW 患者之间平均 rCBF、rCBV 和 DeltaMTT 的差异。
随着颈动脉狭窄程度的增加，同侧 rCBF 逐渐降低（分别为 1.09±0.06、0.93±0.06、0.90±0.04 和 0.83±0.04ml/100g/min；p=0.005），DeltaMTT 逐渐增加（分别为-0.02±0.33、0.16±0.34、1.08±0.22 和 1.47±0.20s；p<0.001）。rCBV 与狭窄程度无关。CoW 的形态与脑灌注参数之间没有关系。
在有症状性颈动脉狭窄的患者中，脑灌注与狭窄程度呈负相关。未发现 CoW 的形态与脑灌注之间存在关系，这表明其他侧支途径起着重要作用。
