Imaging vascular calcification: Where are we headed

Abstract

Abstract Arterial calcium deposition occurs in response to a spectrum of inflammatory and degenerative processes. Hydroxyapatite crystals are the building blocks of vascular calcification and are laid down as an early feature. This microcalcification exhibits a distinct biological profile from established calcified plaque, which is often the marker of quiescent disease. Detecting microcalcification offers great promise because it is associated with intense biological activity within the vascular bed and increased plaque vulnerability. Established imaging techniques, such as computed tomography, cannot identify microcalcification because it occurs at an extremely small scale. 18F-sodium fluoride is a biological radiotracer that binds to exposed hydroxyapatite crystals and can be detected using positron emission tomography (PET). 18F-sodium fluoride PET identifies microcalcification associated with high-risk atherosclerotic plaques that would otherwise require invasive imaging to be detected. Anatomical imaging is already an essential tool to stratify the risk of future cardiovascular events caused by calcifying disease. Combining these imaging techniques with the molecular insights of 18F-sodium fluoride PET offers a comprehensive assessment of vascular calcification. Together, this combination of structural and molecular assessment represents the next major paradigm in cardiovascular imaging and risk stratification.