Newell D W, Aaslid R
Department of Neurological Surgery, University of Washington School of Medicine, Seattle.
Cerebrovasc Brain Metab Rev. 1992 Summer;4(2):122-43.
Blood flow velocity in the basal intracranial arteries can be reliably recorded using transcranial Doppler (TCD) ultrasonography. The utility of Doppler ultrasound in detecting stenosis of arteries has therefore been extended to include the intracranial basal arteries. This has been useful in detecting intracranial stenosis from a variety of causes including atherosclerosis and vasospasm induced by subarachnoid hemorrhage. Changes in cerebral hemodynamics during significantly increased intracranial pressure have also been detected, and have been useful in warning of compromise of the cerebral circulation in head injury. The assessment of the final hemodynamic effects of occlusive disease on the middle cerebral artery can be studied using the CO2 reactivity test. This offers additional diagnostic information in these patients. The direct detection of intracranial microemboli using TCD is also now possible and this has implications in the management of patients with stroke and transient ischemic attacks. Continuous monitoring of the middle cerebral artery velocity has been useful in indicating relative blood flow changes through this artery under certain specific circumstances. By providing continuous information on relative blood flow changes, the dynamics of the cerebral circulation can be studied in more detail. This has allowed the assessment of cerebral autoregulation, as well as blood flow changes, due to changes in cortical activity induced by visual stimulation. Further research on the dynamics of the human cerebral circulation will be possible using this technology.
使用经颅多普勒（TCD）超声检查能够可靠地记录颅内基底动脉的血流速度。因此，多普勒超声在检测动脉狭窄方面的应用已扩展至颅内基底动脉。这在检测由多种原因引起的颅内狭窄方面很有用，这些原因包括动脉粥样硬化和蛛网膜下腔出血所致的血管痉挛。颅内压显著升高时脑血流动力学的变化也已被检测到，这对于警告头部损伤时脑循环受损很有帮助。使用二氧化碳反应性试验可以研究闭塞性疾病对大脑中动脉最终血流动力学的影响。这为这些患者提供了额外的诊断信息。现在使用TCD直接检测颅内微栓子也是可行的，这对中风和短暂性脑缺血发作患者的管理具有重要意义。在某些特定情况下，持续监测大脑中动脉速度有助于指示通过该动脉的相对血流变化。通过提供有关相对血流变化的持续信息，可以更详细地研究脑循环动力学。这使得能够评估脑自动调节以及由于视觉刺激引起的皮质活动变化导致的血流变化。使用这项技术对人类脑循环动力学进行进一步研究将成为可能。
