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PET-MRI Imaging in Patients With Symptomatic Carotid Artery Stenosis

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03215550
Recruitment Status : Completed
First Posted : July 12, 2017
Last Update Posted : February 11, 2020
Information provided by (Responsible Party):
University of Edinburgh

Brief Summary:
Ischaemic stroke is a major cause of death and disability worldwide. In patients with recent stroke, the 18F-fluoride positron emission tomography-computed tomography highlights high-risk culprit carotid plaque and is more discriminatory than 18F-fluorodeoxyglucose. Using hybrid positron emission tomography-magnetic resonance imaging investigators propose to build upon these findings by prospectively assessing 18F-fluoride uptake in a broad range of patients with acute transient ischaemic attack or ischaemic stroke. Investigators will specifically examine the association of 18F-fluoride uptake with multiparametric magnetic resonance imaging assessments of atherosclerotic plaque, especially the role of thrombus and lipid. Finally, using transcranial Doppler and diffusion-weighted magnetic resonance brain imaging, an assessment of the functional consequences of 18F-fluoride-positive atherosclerotic plaque will be performed. If successful, this technique has a number of valuable translational applications including the better selection of patients for carotid intervention.

Condition or disease Intervention/treatment
Stroke Carotid Stenosis Procedure: CEA Radiation: 18F PET-MRI Diagnostic Test: Transcranial Doppler

Detailed Description:
The ability to identify the culprit carotid plaque represents a key goal in carotid artery imaging. Although an array of non-invasive imaging techniques can detect a wide spectrum of complementary high-risk characteristics, no single modality can reliably identify vulnerable plaques associated with future stroke development. Substantial histological data suggests that specific plaque components identify patients at high-risk for future ipsilateral stroke and cardiovascular events. This implies that investigators need to look beyond the traditional paradigm where the basis for carotid endarterectomy were formulated by an invasive imaging modality that provided no information on the arterial wall composition. Alternative imaging strategies are therefore required targeting not only in vivo carotid morphology but also plaque biology and disease activity. This is fundamental to optimal risk-stratification and appropriate selection of patients for high-risk vascular intervention. One new approach is to use non-invasive molecular imaging targeted at plaque biology using hybrid systems such as positron emission tomography-magnetic resonance imaging.

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Study Type : Observational
Actual Enrollment : 20 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Hybrid 18F-fluoride Positron Emission Tomography-Magnetic Resonance Imaging in Patients With Symptomatic Carotid Artery Stenosis
Actual Study Start Date : October 12, 2017
Actual Primary Completion Date : January 10, 2020
Actual Study Completion Date : January 10, 2020

Resource links provided by the National Library of Medicine

Group/Cohort Intervention/treatment
Carotid Endarterectomy
Patients who are scheduled to undergo carotid endarterectomy for symptomatic carotid artery stenosis (≥50% by NASCET criteria for men, ≥70% for women) who are above 40 years of age.
Procedure: CEA
Carotid Endarterectomy

Radiation: 18F PET-MRI
18F-fluoride Hybrid PET-MRI

Diagnostic Test: Transcranial Doppler
Microembolic Signals detection

Primary Outcome Measures :
  1. 18F-fluoride uptake in the culprit plaque in carotid, aortic and intra-cranial vessels. [ Time Frame: 2 weeks ]
    18F-fluoride uptake will be measured by the mean and max Standardised Uptake Values (SUV) derived from the culprit atherosclerotic plaques.

Biospecimen Retention:   Samples Without DNA
At the time of carotid endarterectomy, which is an established surgical intervention aimed at reducing the future risk of stroke in symptomatic patients, tissue will be collected, and lesion integrity and geometry will be preserved as much as possible. Specimens will be photographed in detail to permit subsequent assessment by independent and blinded reviewers. The excised tissue will be aligned and labelled to permit orientation in the carotid artery axis before undertaking 7.4 T magnetic resonance spectroscopy. Subsequently, carotid plaque will be snap frozen in liquid nitrogen. Cellular content, macrophage infiltration, apoptosis, and calcification-associated molecules within the plaques will be assessed by RNA analysis, immunohistochemistry and immunofluorescence using a variety of validated markers.

Information from the National Library of Medicine

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Ages Eligible for Study:   40 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Patients with evidence of an acute stroke, transient ischaemic attack or amaurosis fugax will be recruited as early as possible, but within 14 days of symptom onset. All patients will undergo careful clinical evaluation including carotid Doppler ultrasound assessment and magnetic resonance imaging of the brain. This cohort will be identified at the point they are referred to a vascular surgeon at Edinburgh Royal Infirmary.

Inclusion Criteria:

• Patients with carotid artery stenosis (>50% for men and >70% for women, by NASCET criteria) above 40 years of age.

Exclusion Criteria:

  • Patients with new stroke and a modified Rankin score >3
  • Chronic kidney disease with an estimated Glomerular Filtration Rate (eGFR) of <30 ml/min/1.73 m2
  • Atrial fibrillation
  • Pregnant women
  • Prior ipsilateral carotid intervention
  • Prior neck radiotherapy
  • Inability to tolerate the supine position
  • Participation in the study would result in delay to surgery
  • Psychiatric illness/social situations that would limit compliance with study requirements
  • History of allergic reaction attributed to 18F-fluoride
  • History of allergic reaction to gadolinium contrast media
  • Metal implants and devices including pacemakers and defibrillators

Information from the National Library of Medicine

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 identifier (NCT number): NCT03215550

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United Kingdom
Centre for Cardiovascular Science
Edinburgh, United Kingdom, EH16 4SB
Sponsors and Collaborators
University of Edinburgh
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Responsible Party: University of Edinburgh Identifier: NCT03215550    
Other Study ID Numbers: AC17046
First Posted: July 12, 2017    Key Record Dates
Last Update Posted: February 11, 2020
Last Verified: February 2020
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by University of Edinburgh:
atherosclerosis, imaging
Additional relevant MeSH terms:
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Carotid Stenosis
Constriction, Pathologic
Pathological Conditions, Anatomical
Carotid Artery Diseases
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Arterial Occlusive Diseases
Vascular Diseases
Cardiovascular Diseases