Open Access

Franka Risch

• This cumulative dissertation introduces the technical principles of spectral imaging using computed tomography (CT) and, in subsequent publications, presents potential clinical applications of photon-counting detector CT data. Photon-counting detectors, which became available for clinical use in 2021, are characterized in part by their ability to directly measure the energy of each incident photon. This inherent spectral sensitivity allows easy application of various post-processing techniques, such as material decomposition and virtual monoenergetic imaging, which can be translated into a variety of clinical applications. The results of the studies comprising this dissertation have shown that the signal of iodinated contrast agent can be reliably removed from CT angiography, providing additional information. The resulting virtual noncontrast image series are suitable for quantification of coronary and aortic valve calcification as well as epicardial adipose tissue. Precise contrastThis cumulative dissertation introduces the technical principles of spectral imaging using computed tomography (CT) and, in subsequent publications, presents potential clinical applications of photon-counting detector CT data. Photon-counting detectors, which became available for clinical use in 2021, are characterized in part by their ability to directly measure the energy of each incident photon. This inherent spectral sensitivity allows easy application of various post-processing techniques, such as material decomposition and virtual monoenergetic imaging, which can be translated into a variety of clinical applications. The results of the studies comprising this dissertation have shown that the signal of iodinated contrast agent can be reliably removed from CT angiography, providing additional information. The resulting virtual noncontrast image series are suitable for quantification of coronary and aortic valve calcification as well as epicardial adipose tissue. Precise contrast agent concentration measurements were demonstrated on the complementary iodine image series. Virtual monoenergetic reconstructions were evaluated for its utility in contrast enhancement for cryoablation in the low keV range and artifact reduction of dental material at high keV with promising results. In summary, several research questions have been pursued that explore the potential and limitations of the detector technology for clinical application.…