Non-invasive Doppler ultrasonographic study of cerebral arteries [transcranial Doppler(TCD)] has been extensively applied on both outpatient and inpatient settings. It is performed placing a low-frequency(≤ 2 MHz) tr...Non-invasive Doppler ultrasonographic study of cerebral arteries [transcranial Doppler(TCD)] has been extensively applied on both outpatient and inpatient settings. It is performed placing a low-frequency(≤ 2 MHz) transducer on the scalp of the patient over specific acoustic windows, in order to visualize the intracranial arterial vessels and to evaluate the cerebral blood flow velocity and its alteration in many different conditions. Nowadays the most widespread indication for TCD in outpatient setting is the research of right to left shunting, responsable of so called "paradoxical embolism", most often due to patency of foramen ovale which is responsable of the majority of cryptogenic strokes occuring in patients younger than 55 years old. TCD also allows to classify the grade of severity of such shunts using the so called "microembolic signal grading score". In addition TCD has found many useful applications in neurocritical care practice. It is useful on both adults and children for day-to-day bedside assessment of critical conditions including vasospasm in subarachnoidal haemorrhage(caused by aneurysm rupture or traumatic injury), traumatic brain injury, brain stem death. It is used also to evaluate cerebral hemodynamic changes after stroke. It also allows to investigate cerebral pressure autoregulation and for the clinical evaluation of cerebral autoregulatory reserve.展开更多
Objective To discuss the clinical ultiliazation and significance of microembolus detection by transcranial Doppler （TCD） sonography in intracranial stenosis-occlusive disease. Data sources All related articles in th...Objective To discuss the clinical ultiliazation and significance of microembolus detection by transcranial Doppler （TCD） sonography in intracranial stenosis-occlusive disease. Data sources All related articles in this review were mainly searched from PubMed published in English from 1996 to 2012 using the terms of microembolic signal, transcranial Doppler, intracranial stenosis, stroke. Study selection Original articles and reviews were selected if they were related to the clinical utilization of microembolus detection in intracranial stenosis-occlusive disease. Results Intracranial stenosis is a significant cause of cerebral emboli, and microembolus detection by TCD sonography were widely used in exploring the mechanisms of ischemic stroke with intracranial stenosis （including the middle cerebral artery stenosis and the vertebral-basilar stenosis）, evaluating the prognosis of acute stroke, evaluating the therapeutic effects, and predicting the recurrent events of stroke. Conclusion Microembolus detection by TCD sonography plays an important role in the cerebral ischemic stroke patients with intracranial stenosis.展开更多
文摘Non-invasive Doppler ultrasonographic study of cerebral arteries [transcranial Doppler(TCD)] has been extensively applied on both outpatient and inpatient settings. It is performed placing a low-frequency(≤ 2 MHz) transducer on the scalp of the patient over specific acoustic windows, in order to visualize the intracranial arterial vessels and to evaluate the cerebral blood flow velocity and its alteration in many different conditions. Nowadays the most widespread indication for TCD in outpatient setting is the research of right to left shunting, responsable of so called "paradoxical embolism", most often due to patency of foramen ovale which is responsable of the majority of cryptogenic strokes occuring in patients younger than 55 years old. TCD also allows to classify the grade of severity of such shunts using the so called "microembolic signal grading score". In addition TCD has found many useful applications in neurocritical care practice. It is useful on both adults and children for day-to-day bedside assessment of critical conditions including vasospasm in subarachnoidal haemorrhage(caused by aneurysm rupture or traumatic injury), traumatic brain injury, brain stem death. It is used also to evaluate cerebral hemodynamic changes after stroke. It also allows to investigate cerebral pressure autoregulation and for the clinical evaluation of cerebral autoregulatory reserve.
基金This work was supported by grants from the National Natural Science Foundation of China （No. 81100855） and the Health Department of Jilin （No. 2009Z064）. Conflict of interest： none.
文摘Objective To discuss the clinical ultiliazation and significance of microembolus detection by transcranial Doppler （TCD） sonography in intracranial stenosis-occlusive disease. Data sources All related articles in this review were mainly searched from PubMed published in English from 1996 to 2012 using the terms of microembolic signal, transcranial Doppler, intracranial stenosis, stroke. Study selection Original articles and reviews were selected if they were related to the clinical utilization of microembolus detection in intracranial stenosis-occlusive disease. Results Intracranial stenosis is a significant cause of cerebral emboli, and microembolus detection by TCD sonography were widely used in exploring the mechanisms of ischemic stroke with intracranial stenosis （including the middle cerebral artery stenosis and the vertebral-basilar stenosis）, evaluating the prognosis of acute stroke, evaluating the therapeutic effects, and predicting the recurrent events of stroke. Conclusion Microembolus detection by TCD sonography plays an important role in the cerebral ischemic stroke patients with intracranial stenosis.
