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This research theme is jointly led by:
Peter Jezzard (firstname.lastname@example.org)
Tom Okell (email@example.com)
We are collaborating with clinical colleagues to develop novel MRI acquisition and analysis methods that address the wide spectrum of cerebrovascular disease.
Cerebrovascular disease research is a growing interdisciplinary strength at Oxford, particularly with the opening of the Acute Vascular Imaging Centre (AVIC) in 2012. The FMRIB Physics Group is at the heart of this effort to initiate a neurovascular imaging research programme, developing methods that aim to improve diagnosis and treatment of diseases such as stroke, atherosclerosis and arteriovenous malformation. We are focusing on the development of non-invasive techniques to visualise both blood supply to the brain and alterations in tissue metabolism that result from blood flow disruption.
One area of focus is the use of a technique called arterial spin labelling (ASL) to non-invasively ”tag" the blood and subsequently visualise its passage through the arteries and into the brain tissue. We are developing methods which optimise the quantification of perfusion in the minimum possible time, allow simultaneous visualisation of blood flow within blood vessels and into the tissue, and separately identify the blood flow arising from individual vessels in the neck. This enables us to see whether narrowing or blockage of an artery is being compensated for by other arteries. We are also developing a related technique to allow the estimation of how much oxygen is being extracted from the blood in specific areas of the brain. Increased oxygen extraction can be indicative of tissue that is struggling to receive sufficient blood supply to meet its metabolic demand.
These approaches are being used in conjunction with a novel technique based on chemical exchange saturation transfer (CEST), which gives information about the chemical environment within the brain tissue. We are primarily using this technique to estimate tissue pH, which shows promise as a sensitive marker of metabolic stress and therefore tissue at increased risk of damage.
Finally, we are also developing methods to efficiently remove the signal arising from blood, enabling much clearer images of the vessel walls to be obtained. This will aid characterisation of atherosclerotic plaques, which can lead to the formation of a blood clot. These blood clots can block the artery entirely, or break free and block a smaller artery downstream, potentially causing a stroke.
View our publications.
This research is conducted as part of the Physics Group at the Wellcome Centre for Integrative Neuroimaging.