Room: Exhibit Hall | Forum 1
Purpose: This study investigated contrast cancellation phenomenon of diluted contrast agents in energy integrating system and compared it with photon counting system in contrast enhanced digital mammography (CEDM).
Methods: We simulated two different systems which were constructed with amorphous Selenium (a-Se) and Cadmium Zinc Telluride (CZT) using Geant4 Application for Tomographic Emission (GATE) version 6.0. The simulation was modeled for a range of low concentration of iodine and tube voltage. To improve the contrast of iodine, the projection-based weighting technique was applied to each energy bin (22-29, 30-33, 34-37, 38-40, and 41-45 keV) based on photon counting system.
Results: For comparison with projection-based weighted images, we obtained energy integrating images and K-edge image at bin 3 (34-37 keV). The results indicated that the CNR value for the low concentration of iodine in the energy integrating image and K-edge imaging are less than or equal to zero. On the other hand, the CNR values of low concentration iodine were significantly improved in the projection-based weighted image.
Conclusion: In conclusion, contrast cancellation phenomenon, which was usually occurred in diluted iodine contrast agent, was effectively overcome by using projection-based weighting method based on photon counting system. Therefore, we expected that our study would contribute to reduce concentration of iodine contrast agent in clinical applications.
Funding Support, Disclosures, and Conflict of Interest: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2017R1A2B2001818).
Contrast Agent, Photon Detectors, Image Analysis