ABSTRACT
Photon counting detector (PCD)-based x-ray computed tomography (CT) has a great potential in many clinical applications. One of the major challenges is that the spectrum recorded by PCDs is distorted due to charge sharing, K-escape x-rays, K-shell fluorescence emission and reabsorption, etc. The energy deposited by a photon may be split and detected by neighboring pixels, resulting in two to four counts at lower energies. PCD data may be spatially and energetically correlated. To our knowledge, detector models for such recorded spectra have been developed, presented, but not shared among imaging scientists and community. In addition, most simulation tools are stochastic Monte Carlo simulations that are not computationally efficient. It would be desirable to have a shared efficient simulation tool for simulating x-ray PCD-CT projection data with distorted spectra. In this chapter, we outline a PCD model for the cross-talks between neighboring PCD pixels due to charge sharing. The developed software package is called PcTK for Photon Counting Toolkit and available for researchers in academic institutions. Interested readers should visit https://pctk.jhu.edu">pctk.jhu.edu for more information.
