Pushing Spatiotemporal Limits for 4D Flow MRI and Dynamic MRA in the Brain at Ultra-High Field

Study Overview
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Brief Summary
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This study aims at investigating the blood hemodynamics with high spatiotemporal resolution in patients with brain aneurysms and AVMs as well as in healthy controls. Parameters such as peak blood velocity, wall shear stress and other derived parameters will be obtained from 4D flow MRI data acquired at ultra-high field strength (7 Tesla).

Detailed Description
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The hemodynamic factors responsible for hemorrhagic stroke, resulting in wide variations in the clinical management of underlying vascular lesions, especially when they are found in asymptomatic individuals or individuals with symptoms not related to the disease. Therefore, there is an urgent need for the development of reliable biomarkers based on hemodynamic parameters, which can then enable improvements in risk assessment in patients presenting with these lesions. This need can be met by non-invasive Magnetic Resonance Imaging (MRI) techniques that provide information on high resolution vascular anatomy, visualization of cerebral hemodynamics and quantitative information about blood velocity. However, such techniques as presently employed at 1.5 or 3 Tesla are limited by spatial resolution and prolonged data acquisition times. The primary goal of this proposal is to overcome these current limitations by exploiting Ultra-High Fields (UHF, i.e. ≥ 7 Tesla (7T)) to attain significantly higher spatial resolution, faster acquisitions and increased lesion conspicuity utilizing Qualitative exploration of intracranial blood hemodynamics, Quantitative imaging of the spatiotemporally resolved blood velocity vector, Derivation of hemodynamic parameters.

Official Title
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Pushing Spatiotemporal Limits for 4D Flow MRI and Dynamic MRA in the Brain at Ultra-High Field

Conditions
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Stroke

Intervention / Treatment
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* Device: 7 Tesla MRI


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects / Patients between 18 and 75 Exclusion Criteria: Any kind of ferromagnetic implants. MR-unsafe non-ferromagnetic implants. Cardiac pacemakers. A history of shrapnel or shot gun injury. A body mass index > 40. Severe claustrophobia. Tattoos in the head/neck area or permanent makeup.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy subjects<br>Subjects with no contraindications to magnetic resonance imaging will undergo 4D flow MRI scanning. 7 Tesla MRI | Device: 7 Tesla MRI<br>* MR imaging using a 7 Tesla MR system.<br>|
| Patients<br>Patients with an unruptured brain aneurysm or an unruptured arteriovenous malformation (AVM) with no contraindications to magnetic resonance imaging will undergo 4D flow MRI scanning 7 Tesla MRI | Device: 7 Tesla MRI<br>* MR imaging using a 7 Tesla MR system.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Brain Flow Dynamics | Altered brain flow hemodynamics in patients with aneurysms and AVMs compared to normal subjects | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Stroke, AVM, Aneurysm