ABSTRACT
Over time, imaging systems have become highly specialized with a broad spectrum of X-ray-related modalities. Key characteristics of the X-ray sources largely differ with respect to X-ray spectra, mechanical interfaces, and energy throughput. Since the mid-1970s, computed tomography (CT) has become the workhorse of diagnostic imaging. Information complementary to magnetic resonance imaging and other modalities has made it indispensable for challenging X-ray diagnostic tasks, as once more demonstrated during the current COVID-19 pandemic. Radon died in 1956 without ever anticipating the great importance of his work of pure mathematics for modern medicine. As a basis for solving the conundrum of the spatial interior of a patient, CT measures the so-called Radon transform from X-ray flux signals and backprojects the spatially distributed X-ray attenuation characteristics of the object as a function in real space. The mathematics of efficient image reconstruction and its numeric is too complex to be comprehensively discussed in this context. Sophisticated details are vendor-specific and proprietary.
