A simple scatter correction method for dual energy contrast-enhanced digital breast tomosynthesis

Abstract

Dual-Energy Contrast Enhanced Digital Breast Tomosynthesis (DE-CE-DBT) has the potential to deliver diagnostic information for vascularized breast pathology beyond that available from screening DBT. DE-CE-DBT involves a contrast (iodine) injection followed by a low energy (LE) and a high energy (HE) acquisitions. These undergo weighted subtraction then a reconstruction that ideally shows only the iodinated signal. Scatter in the projection data leads to “cupping” artifacts that can reduce the visibility and quantitative accuracy of the iodinated signal. The use of filtered backprojection (FBP) reconstruction ameliorates these types of artifacts, but the use of FBP precludes the advantages of iterative reconstructions. This motivates an effective and clinically practical scatter correction (SC) method for the projection data. We propose a simple SC method, applied at each acquisition angle. It uses scatter-only data at the edge of the image to interpolate a scatter estimate within the breast region. The interpolation has an approximately correct spatial profile but is quantitatively inaccurate. We further correct the interpolated scatter data with the aid of easily obtainable knowledge of SPR (scatter-to-primary ratio) at a single reference point. We validated the SC method using a CIRS breast phantom with iodine inserts. We evaluated its efficacy in terms of SDNR and iodine quantitative accuracy. We also applied our SC method to a patient DE-CE-DBT study and showed that the SC allowed detection of a previously confirmed tumor at the edge of the breast. The SC method is quick to use and may be useful in a clinical setting.