Essig Marco, Nikolaou Konstantin, Meaney James F M
Department of Radiology, German Cancer Research Center Im Neuenheimer Feld 280, 69120 Heidelberg.
Eur Radiol. 2007 Mar;17 Suppl 2:B30-7.
Stroke, a major cause of death and disability in the developed world, is usually caused by atherosclerosis, most commonly an arterioocclusive lesion at the carotid bifurcation. Numerous multicentre trials have demonstrated that carotid endarterectomy can reduce the risk of stroke in these patients. However, because of the morbidity of catheter angiography coupled with the risks of surgery, the benefits outweigh the risks of surgery only for those with >70% carotid artery stenosis. The gold standard method for assessing the degree of stenosis is catheter-directed cerebral digital subtraction angiography; however, this is associated with a small but substantial stroke risk in addition to inherent risks associated with use of ionizing radiation and nephrotoxic contrast agents. The requirement for alternative imaging techniques that do not contribute to morbidity is ideally met by contrast-enhanced magnetic resonance angiography, which eliminates the need for direct catheterization and therefore eliminates stroke risk associated with a patient work-up. Advances in contrast-enhanced magnetic resonance angiography technology have led to a technique that achieves the goals of high spatial and temporal resolution required for stenosis assessment and streamlining of patients along surgical or medical lines. With the advent of a novel contrast agent, gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany), which has a high relaxivity and an extended imaging time, improved diagnosis of carotid artery stenoses with magnetic resonance angiography can be expected. Gadofosveset trisodium facilitates improved first-pass imaging and also delays steady-state imaging with one injection. Although developed for vascular imaging, gadofosveset trisodium may also allow assessment of brain vascularity, blood-brain barrier breakdown and neurodegenerative disease.
中风是发达国家死亡和残疾的主要原因，通常由动脉粥样硬化引起，最常见的是颈动脉分叉处的动脉闭塞性病变。众多多中心试验表明，颈动脉内膜切除术可降低这些患者中风的风险。然而，由于导管血管造影的发病率以及手术风险，仅对于那些颈动脉狭窄超过70%的患者，手术的益处才大于风险。评估狭窄程度的金标准方法是导管导向的脑数字减影血管造影；然而，除了与使用电离辐射和肾毒性造影剂相关的固有风险外，这还与小但显著的中风风险相关。对比增强磁共振血管造影理想地满足了对不增加发病率的替代成像技术的需求，它消除了直接导管插入的需要，因此消除了与患者检查相关的中风风险。对比增强磁共振血管造影技术的进步导致了一种技术，该技术实现了狭窄评估以及根据手术或医疗路线简化患者所需的高空间和时间分辨率的目标。随着新型造影剂钆特醇三钠（德国柏林拜耳先灵医药公司的 Vasovist）的出现，其具有高弛豫率和延长的成像时间，可以预期磁共振血管造影对颈动脉狭窄的诊断会得到改善。钆特醇三钠有助于改善首次通过成像，并且一次注射还能延迟稳态成像。尽管是为血管成像而开发的，但钆特醇三钠也可能允许评估脑血管情况、血脑屏障破坏和神经退行性疾病。
