ABSTRACT
Since the advent of spiral computed tomography in the early 1990s, the chase of the “magic triangle of CT imaging” (see Figure 39.1), was the driving force for the Computed Tomography (CT) “slice war” that went on for about two decades. Having reached a plateau regarding speed, coverage, and isotropic resolution, and having managed to adequately fulfill the demands for reliable cardiac CT and perfusion studies, the CT slice war was brought to an end in the late 2000s. However, a new challenge between vendors soon emerged, associated with the dual energy CT (DECT) imaging (Lell et al. 2015, Mahesh et al. 2013). The term “dual energy CT” refers to acquisition of data corresponding to two different photon spectra, and, therefore, it is also referred as “spectral CT.” The idea to employ CT beams of different spectra to enhance material differentiation had already been conceptualized during the 1970s, soon after the first clinical CT (Alvarez and Macovski 1976), but DECT did not achieve clinical significance and widespread clinical application till the introduction of dual-source CT systems in 2006. Ever since, DECT has been a new exciting field for the radiology community, and the main driving force for CT technology advancement.
