K-edge subtraction imaging for angiography at a compact synchrotron source

About one third of all deaths worldwide can be traced back to some form of cardiovascular disease. The gold standard for the diagnosis and interventional treatment of blood vessels is digital subtraction angiography (DSA). An alternative to DSA is K-edge subtraction (KES) imaging, which has been shown to be advantageous for moving organs and to eliminate image artifacts caused by patient movement. As highly brilliant, monochromatic X-rays are required for this method, it has been limited to synchrotron facilities so far, restraining the applicability in clinical routine. Over the past decades, compact synchrotron X-ray sources based on inverse Compton scattering have been evolving, which provide X-rays with sufficient brilliance and that meet spatial and financial requirements affordable in laboratory settings or for university hospitals. In this study, we demonstrate a proof-of-principle KES imaging experiment using the Munich Compact Light Source (MuCLS), the first user-dedicated installation of a compact synchrotron X-ray source worldwide. It is shown that the proposed filter-based KES method allows for iodine-contrast agent and calcium to be clearly separated, thereby providing X-ray images only showing one of the two materials. The results show that the quasi-monochromatic spectrum of the MuCLS enables filter-based K-edge subtraction imaging and can become an important tool in pre-clinical research and possible future clinical diagnostics.