A scatter correction method for contrast-enhanced digital breast tomosynthesis with a dual-layer detector

Abstract

Contrast-enhanced digital breast tomosynthesis (CEDBT) utilizes iodinated contrast agents and spectral imaging techniques to highlight breast tumors with neo-angiogenesis. Conventional dual-shot (DS) CEDBT suffers from motion artifacts due to patient motion between two separate x-ray exposures for the sequential acquisitions of high- and low-energy (HE and LE) images. To mitigate motion artifacts, a new CEDBT system was designed with a direct-indirect dual-layer (DL) detector. It enables simultaneous acquisition of HE and LE images with a single exposure. Our previous study has demonstrated the feasibility of the DL detector to cancel normal breast tissue and provide lesion contrast comparable to DS. Due to the absence of anti-scatter grids, both DS- and DL-CEDBT suffer image quality degradation from scattered radiation, which introduces cupping artifacts and reduces lesion contrast. In this study, we are proposing a hybrid scatter correction method, which combines the straightforward kernel-based iterative convolution method and the empirical interpolation method. The hybrid method was applied to Monte Carlo (MC) simulated DL-DBT projection images of anthropomorphic digital breast phantoms of varying glandularity and compressed thickness. Results showed that the hybrid method improves scatter estimation accuracy compared to the single-kernel iterative convolution method. The hybrid method was applied to a clinical DS-CEDBT case for scatter correction. The results showed reduced cupping artifacts and improved lesion contrast.