Introduction to “Realistic Simulation of real CT systems with a basic-qualified Simulation Software - CTSimU2“ - Reuter, Tamara; Borges de Oliveira, Fabricio; Abt, Christian; Ballach, Frederic; Bartscher, Markus; Bellon, Carsten; Dennerlein, Frank; Fuchs, Patrick; Günnewig, Olaf; Hess, Jonathan; Kasperl, Stefan; Maass, Nicole; et al. (Special Issue of e-Journal of Nondestructive Testing (eJNDT), 2023)