Dual Energy and Spectral CT Techniques in Cardiovascular Imaging

Abstract

More and more clinical CT scanners have Dual Energy CT capabilities, and routine usage of this technique, as well as the number of scientific publications on this topic, is increasing rapidly. At the moment, several technical approaches are commercially available that have different strengths and weaknesses. Also, post-processing features differ considerably between different software products. However, the need for a certain degree of standardization has already been recognized by the community. For cardiovascular imaging, the main focus of Dual Energy CT is on the visualization and quantification of iodinated contrast media in vessels. Virtual monoenergetic images allow for an interactive optimization of iodine contrast relative to soft tissue, calcium, or stent material. Virtual monoenergetic CT number values are independent of the patient or the prefiltration of the used scanner; they are in this way more objective and reproducible. Additional diagnostic information is available through the calculation of iodine maps for the heart and lungs. While some of the discussed applications are at the very early stage of feasibility studies, others, such as bone removal, virtual monoenergetic imaging, or visualization of iodine uptake in the lung parenchyma, are already now widely used.