Cardiovascular — Sub-theme 4: Cardio- and Neuro-vascular Imaging Development

Sub-theme leads: Prof Peter Jezzard and Dr Matthew Robson

Oxford has an internationally leading programme in this area, mainly focused on novel MRI techniques, with cutting-edge facilities (www.ocmr.ox.ac.uk, www.fmrib.ox.ac.uk and www.avic.ox.ac.uk), and closely integrated with the clinical research teams. For example, we have the only human 7T Magnetic Resonance system in the UK capable of whole-body imaging; we plan to install the UKs first clinical MRI hyperpolarisation system at the Oxford Centre for Clinical Magnetic Resonance Research (OCMR) by end of 2012.

Diffusion in hypertrophic cardiomyopathy

Diffusion in hypertrophic cardiomyopathy
SSFP and DTI (fractional anisotrophy) images of a normal volunteer (top two images) and an HCM patient. The HCM patient demonstrates hypertrophy and fibre disarray, indicated by a reduced fractional anisotrophy.

We are developing novel imaging methods to phenotype the cardiovascular system such as tissue characterisation techniques to define the state of the heart muscle based on novel MRI methods, without need for contrast agent or stress. At 7T, we are establishing non-invasive coronary angiography (imaging of the blood vessels of the heart) in order to evaluate them and improved assessment of heart muscle energetics (energy transformation) by MR spectroscopy. We also have the opportunity to establish the revolutionary new technology of hyperpolarised cardiac 13C-MRI, which amplifies the 13C-MR signal up to 100,000-fold. This will allow us to assess many aspects of heart metabolism in heart conditions at high temporal and spatial resolution. In brain imaging, we work on quantitative measures of cerebral (brain) blood flow (CBF), vessel wall imaging and dynamic angiography to assess collateral circulation, (the different pathways for blood to reach the tissues). We are further speeding up acquisition, to achieve 3D high resolution and dynamic temporal coverage. MR-based indicators of metabolically stressed brain tissue (of local oxygen extraction fraction and pH) are being compared with existing methods (e.g. diffusion-perfusion mismatch). MR spectroscopy in acute stroke will yield insights into glial and astrocytic control of CBF.

Relevance of research to the health of patients and the public: Safer, quicker and more informative imaging tools will improve understanding of disease mechanisms, diagnosis, therapy monitoring and prognosis assessment.