Paul Segars, PhD and Ehsan Samei, PhD (Radiology) received an NIH/NIBIB R01 grant entitled “Simulation tools for 3D and 4D CT.” First funded in 2005, the latest competing renewal provides an additional 4 years of research support. Photon-counting CT (PCCT) is an emerging new medical imaging technology that can provide better spatial resolution, artifact reduction, and material decomposition. The purpose of this grant is to develop a virtual framework to optimize photon-counting devices and applications in CT imaging. Samei and Segars will use this framework to conduct virtual imaging trials (VITs), where the diagnostic performance of PCCT can be rigorously assessed using realistic models of patient anatomy, CT scanner physics, and radiologist interpretations. VITs can efficiently evaluate imaging technology in ways that are not practical or even possible in the real clinical trials. The long term goal is to establish the usefulness of PCCT in oncologic and cardiac applications. This research takes advantage of the close collaboration that Samei and Segars have developed with industry and the NIH Department of Radiology.