Cardiovascular Imaging
Cardiovascular diseases are the leading cause of death globally. We use advanced biomedical imaging techniques to monitor disease progression and efficacy of novel therapeutics.
Using biomedical imaging to tackle heart disease
Every year, approximately 8 million people die from coronary heart disease and 7 million from stroke. Although treatments are improving, mortality rates continue to increase, and it is vital that we develop new therapies.
Imaging is integral to the diagnosis and prognosis of cardiovascular disease. We use advanced biomedical imaging techniques to monitor disease progression and efficacy of novel therapeutics in live rodent models of cardiovascular disease.
This research identifies new treatment strategies and novel physiological and pathological pathways.
Principal investigators
Meet the principal investigators advancing imaging to drive breakthroughs in heart disease research.
Professor of Cardiovascular Imaging at the Department of Imaging
Professor of Cardiovascular Imaging at the Department of Imaging
Imaging cardiac morphology and function
Heart structure and function are altered by disease. Using CINE-MRI and ultrasound we can accurately identify changes in contractility, chamber volume, mass, and aortic flow, while vascular structures can be assessed using contrast enhanced CT.
Image: An infarcted mouse heart.
Image: Top row: CINE-MRI at 3 progressing time-points (columns). Bottom row: late gadolinium enhancement for viability imaging. The evolution of the infarcted scar tissue and ventricular dilation over time shows from left to right.
Imaging cardiac viability and fibrosis
Ischemia rapidly leads to cell death and subsequent fibrosis. These changes can be indirectly assessed by MRI after injection of Gadolinium based contrast agents. In myocardial infarction the contrast agent accumulates within the infarcted tissue, enhancing the MRI signal from the effected region, while in pathologies such as hypertension and aortic stenosis that result in diffuse accumulation of fibrosis, the increased contrast accumulation can be detected using T1 mapping. Positron emission tomography (PET) can also be used to assess tissue viability after infusion of 18F-FDG - a radioactive glucose analogue. Damaged myocardium has lower metabolic rate meaning that the accumulation of glucose is lower in affected regions.
Imaging cardiac perfusion
The rate of blood flow within the myocardium can dramatically affect cardiac function. We use arterial spin labelling (ASL) MRI and first pass dynamic contrast enhancement (DCE) MRI to quantify perfusion within hearts of animal models of cardiac disease.
Image: First pass perfusion of contrast agent in the mouse heart. The hyper-enhancement caused by the contrast can be seen moving first into the blood pool before perfusing the myocardium.
Image: Iron overload: Pathological accumulation of iron in the heart is quantifiable through MRI. The reduction in signal intensity caused by the presence of iron is clear in the iron overload image.
Imaging cardiac iron load
Beta thalassemia major results to accumulation of iron within the myocardium and can lead to cardiac dysfunction. Iron accumulation can be assessed in patients using T2* MRI. We have developed preclinical MRI methods for monitoring iron accumulation and response to therapy in a mouse model of thalassemia.
Imaging cardiac ultrastructure
The helical array of myofibers that make up the structure of the heart are important for efficient contraction. Using diffusion tensor imaging (DTI) and 3D optical imaging, such as optical projection tomography (OPT) we can assess the alignment and disarray of myofibers within whole heart specimens ex vivo.
Image: Imaging across scales: DT-MRI can be used for myofibre orientation and OPT for superstructural anatomical information. Co-registering image sets enables complete quantification of cardiac architecture.
Image: Imaging cardiac regeneration: Fluorescent stem cells form a patch to regenerate regions of myocardium.
Imaging cardiac regeneration
One of the most promising therapies for myocardial infarction and prevention of heart disease is regenerative medicine. In CABI, we investigate the benefits of cardiac and mesenchymal stem cell therapy for the heart.
We follow the beneficial effects of cell therapy on cardiac function using the techniques above. We also track the fate of grafted cells using genetic reporter genes such as luciferase for bioluminescence imaging or norepinephrine transporter for PET/SPECT, and with direct cell labelling with iron oxides, gold nanoparticles and radiotracers.
Retention of grafted stem cells within the heart is low, meaning that beneficial effects are small. We are using tissue engineering approaches to enhance cell engraftment. By grafting cells within nurturing hydrogels or seeded them onto scaffolds we aim to support stem cell survival and enhance regenerative effect.
Specifically, we are developing methods that track the in vivo fate of the biomaterials and the stem cells, providing in vivo information on biomaterial location and degradation, as well as survival of cells within the engineered tissue.
Imaging stroke
MRI can be used to monitor changes in brain tissue after ischemic stroke. We use T2 weighted imaging to monitor vasogenic edema, and a combination of diffusion and perfusion imaging to identify the potentially salvageable penumbra of a stroke lesion.
Image: Using T2 weighted MRI, regions of the brain affected by stroke become hyper-enhanced.
