Abstract:
Objective: Exploring the potential of optimizing Mono+ technology resolution parameters for the reduction of image noise and radiation dose in virtual monoenergetic imaging (VMI). Methods A computerized tomography (CT) quality control phantom was scanned in energy CT mode at different radiation doses (0.8 to 15.0 mGy). Images were reconstructed from VMI acquisitions at 70 keV using Mono technology and Mono+ technology with different resolution parameters (2, 6, 10). A conventional CT scan was performed at 15.0 mGy, and corresponding images were reconstructed from poly-energetic imaging (PEI). The noise power spectrum (NPS) was used to analyze the image noise characteristics. The relationship between image noise and radiation dose was fitted to estimate the potential of VMI reconstructions using different technologies to reduce scan radiation dose. Results As the radiation dose decreased, the image noise in VMI increased. The images reconstructed from VMI using Mono technology had the highest image noise, whereas those reconstructed using Mono+ technology with a resolution parameter of 2 had the lowest image noise. The average and peak spatial frequency values of NPS curves of VMI were close to those of PEI. The images reconstructed from VMI using Mono technology and Mono+ technology with resolution parameters of 2, 6, and 10 achieved the noise level of PEI with radiation dose reductions of 12.0%, 37.3%, 23.6%, and 19.8%, respectively. Conclusion Optimizing the resolution settings in Mono+ technology has the potential to further reduce radiation dose, with an expected reduction of more than one-third compared to that of conventional CT scans.