A software package, Virtual Photographic Radiographic Imaging Simulator (ViPRIS), has been developed for optimizing x-ray radiographic imaging. A tomographic phantom, VIP-Man, constructed from Visible Human anatomical color images is used to simulate the scattered portion of an x-ray system and to compute organ doses using the ESGnrc Monte Carlo code. The primary portion of an x-ray image is simulated using the projection ray-tracing method through the Visible Human CT data set. To produce a realistic image, the software simulates quantum noise, blurring effects, lesions, detector absorption efficiency, and other imaging artifacts. The primary and scattered portions of an x-ray chest image are combined to form a final image for observer studies using computerized simulated observers. Absorbed doses in organs and tissues of the segmented VIP-Man phantom were also obtained from the Monte Carlo simulations to derive effective dose, which is a radiation risk indicator. Approximately 2000 simulated images and 200,000 vectorized image data files were analyzed using ROC/AUC analysis. Results demonstrated the usefulness of this approach and the software for studying x-ray image qualify and radiation dose. |