Spectral X-ray Scatter Correction with an Energy Resolved Photon-Counting Detector

Photon-counting detectors (PCDs) with energy-resolving capabilities are being investigated for x-ray imaging in medical applications. The spectral information obtained with PCDs allow for quantitative material identification of structures within the imaged object. Radiation that scatter from the object obscures the transmitted primary intensity and impedes accurate material identification. Although scatter correction methods have been widely developed for conventional energy-integrating detectors (EIDs), the spectral impact of the object scatter is only recently being investigated. We have explored the effectiveness of a scatter correction method previously designed for conventional EID imaging when applied to spectral imaging with PCDs. This technique relies on a scatter map database generated from homogeneous slabs of varying thickness with equivalent material and geometry as the object. Subtracting the object projection by the appropriate scatter map improves the image quantification. This practical technique provides an effective scatter correction without relying on additional exposure to the patient.