Performance evaluation of total variation (TV) denoising technique for dual-energy contrast-enhanced digital mammography (CEDM) with photon counting detector (PCD): Monte Carlo simulation study

摘要

The dual-energy contrast-enhanced digital mammography (CEDM) system based on a photon counting detector (PCD) is very useful providing functional information for breast cancer detection. In particular, this system can be used to solve the spectral overlap and high radiation dose problems. However, imaging noise is a big problem because of the degradation image performance and cancer detection ratio in the CEDM system. To address this problem, a total variation (TV)-based denoising technique approach has recently been studied. Thus, the aim of this study was to evaluate and confirm the image performance of our TV-based denoising technique with dual energy CEDM with a PCD. For this purpose, we simulated a dual-energy CEDM with a PCD and breast phantom in Monte Carlo simulation using the Geant4 Application for Tomographic Emission (GATE) that is an essential open source program. We also designed a TV-based denoising technique based on the LI-norm estimation included correction and iteration steps for acquiring high edge preservation in X-ray images. To evaluate the image performance, we used evaluation parameters with a contrast-to-noise ratio (CNR) and coefficient of variation (COV) as a function of the absorbed dose levels (2.18, 1.53, 1.09, and 0.66 mGy). According to the results, the average of all iodine thicknesses and absorbed dose conditions for the CNR using our proposed TV-based de noising technique was 1.71, 1.39, and 1.13 times higher than that acquired for the noisy image, median filter and Wiener filter, respectively. We also acquired excellent COV results for the dual-energy CEDM with a PCD system (2.53 times higher than that of the noisy image). In conclusion, the results of this study suggested that a TV based denoising technique can be achieved with an improved image performance and the effect and feasibility of the TV-based denoising technique for dual-energy CEDM with a PCD can be investigated.