Cardiovascular disease (CVD) is the leading cause of death in Europe and costs the economy nearly
€ 200 billion each year. Consequently, there is an urgent need for reliable diagnostic tests which identify patients at risk of CVD, so they can be given the appropriate treatment at an earlier stage, increasing their chance of survival and reducing the cost burden of administering unnecessary treatment. Perfusion, the flow of blood and hence oxygen, is essential to the functioning of the heart, and reduced perfusion, or ischemia, is an early marker of CVD. Accurately measuring perfusion can indicate areas with inadequate blood supply, and therefore patients at risk.
However, the current ‘gold standard’ for accurately quantifying cardiac perfusion is through invasive measurements with catheters which is both costly and has undesirable side-effects. There are non-invasive medical imaging modalities, such as Positron Emission Tomography (PET), Magnetic Resonance Imaging (MRI) and Computed tomography (CT), from which a perfusion measurement can be determined. From the image acquired, a cardiac perfusion map is derived which is used to make clinical decisions. The results can vary significantly between imaging techniques and indeed within the same imaging technique applied at different centres. In addition it can take years of experience to accurately diagnose a patient based on a perfusion map as it is hard to detect small changes in blood flow visually.