Reproducibility Study of Transcranial Doppler
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ClinicalTrials.gov Identifier: NCT03050567 |
Recruitment Status :
Completed
First Posted : February 13, 2017
Last Update Posted : June 25, 2018
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Condition or disease | Intervention/treatment |
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Stroke | Diagnostic Test: Transcranial Doppler Ultrasound |
Study Type : | Observational |
Actual Enrollment : | 40 participants |
Observational Model: | Cohort |
Time Perspective: | Prospective |
Official Title: | Reproducibility Study of Transcranial Doppler Microembolic Signals Detection in the Middle Cerebral Artery |
Actual Study Start Date : | March 17, 2017 |
Actual Primary Completion Date : | August 1, 2017 |
Actual Study Completion Date : | August 9, 2017 |
Group/Cohort | Intervention/treatment |
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Healthy Volunteers
Healthy volunteers with no previous history of cerebrovascular disease and aged over 18 years old.
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Diagnostic Test: Transcranial Doppler Ultrasound
Transcranial Doppler will be performed on the symptomatic (ipsilateral to an index event) middle cerebral artery in a quiet temperature controlled room. The middle cerebral artery will be identified through the temporal window in a supine position with a flow direction towards the probe. The subject will have a head frame (Marc 600 Spencer Technologies, USA) fitted to reduce motion and to secure a constant angle of the middle cerebral artery insonation depth at 50-60 mm from the skull surface. All recordings will be made using the ST3 Transcranial Doppler Ultrasound System (Spencer Technologies, USA) with a 2-MHz transducer for 1 hour. Emboli will be detected by listening for their characteristic short audible sound (range 10-100 ms, intensity threshold above 7 dB) and spectral appearance using the International Consensus Group microembolus identification criteria and an automated Embolus Detection Software (Spencer Technologies, USA). |
Subjects with symptomatic carotid artery stenosis
Patients with symptomatic cerebrovascular event (stroke, transient ischaemic attack or amaurosis fugax) and image confirmed carotid artery stenosis of >30%. This will include patients scheduled for carotid endarterectomy (>50% for men and >70% for women, by North American Symptomatic Carotid Endarterectomy Trial criteria) or treated conservatively with an optimal medical therapy (if patient declined surgical intervention or is outside surgical criteria for carotid endarterectomy).
|
Diagnostic Test: Transcranial Doppler Ultrasound
Transcranial Doppler will be performed on the symptomatic (ipsilateral to an index event) middle cerebral artery in a quiet temperature controlled room. The middle cerebral artery will be identified through the temporal window in a supine position with a flow direction towards the probe. The subject will have a head frame (Marc 600 Spencer Technologies, USA) fitted to reduce motion and to secure a constant angle of the middle cerebral artery insonation depth at 50-60 mm from the skull surface. All recordings will be made using the ST3 Transcranial Doppler Ultrasound System (Spencer Technologies, USA) with a 2-MHz transducer for 1 hour. Emboli will be detected by listening for their characteristic short audible sound (range 10-100 ms, intensity threshold above 7 dB) and spectral appearance using the International Consensus Group microembolus identification criteria and an automated Embolus Detection Software (Spencer Technologies, USA). |
- Presence of microembolic signals in the Middle Cerebral Artery. [ Time Frame: 14 days ]

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Sampling Method: | Non-Probability Sample |
Two cohorts of subjects including healthy volunteers and those with symptomatic carotid artery stenosis will be recruited in different ways. All subjects will undergo basic clinical evaluation prior to participation. In the second cohort, this will include assessment of relevant carotid artery and brain imaging investigations as well.
Healthy volunteers will be recruited from the Centre for Cardiovascular Science at Edinburgh University by the Primary Investigator (PI).
Patients with evidence of an acute neurovascular event (stroke, transient ischaemic attach and retinal ischaemia) due to a symptomatic carotid artery stenosis will be recruited from the acute TIA/Stroke clinics and inpatients at Edinburgh Royal Infirmary by the responsible Consultant Neurologist or Stroke Physician. Once eligible patients are identified at this point PI will recruit subjects into the study.
Inclusion Criteria:
- Healthy volunteers with no previous history of cerebrovascular disease and aged over 18 years old.
- Patients with symptomatic cerebrovascular event (stroke, transient ischaemic attack or amaurosis fugax) and image confirmed carotid artery stenosis of >30%. This will include patients scheduled for carotid endarterectomy (>50% for men and >70% for women, by North American Symptomatic Carotid Endarterectomy Trial criteria) or treated conservatively with an optimal medical therapy (if patient declined surgical intervention or is outside surgical criteria for carotid endarterectomy).
Exclusion Criteria:
- Subjects unable to comply with the study procedures such as a severe disabling stroke.
- Inadequate temporal window for Transcranial Doppler assessment.
- Adults with incapacity.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03050567
United Kingdom | |
Centre for Cardiovascular Science | |
Edinburgh, United Kingdom, EH16 4SB |
Responsible Party: | University of Edinburgh |
ClinicalTrials.gov Identifier: | NCT03050567 |
Other Study ID Numbers: |
AC16131 |
First Posted: | February 13, 2017 Key Record Dates |
Last Update Posted: | June 25, 2018 |
Last Verified: | May 2017 |
Microemboli |