Spectral Beam Shaping in X-Ray CT: Survey of Clinical Applications, Dose and Image Quality

Abstract

This survey synthesizes evidence on spectral beam shaping in X-ray computed tomography (CT) using tin/silver filtration (Sn/Ag-filtered acquisition), focusing on clinical applications, radiation dose, and image quality. Target domains include chest imaging, pediatrics, paranasal sinuses, musculoskeletal examinations, urinary stone detection, coronary calcium scoring, interventional radiology, and the localizer radiograph. Across indications, many studies reported substantial reductions in output dose and effective dose (approximately 20-90％) with preserved diagnostic performance. Trade-offs include decreased tissue contrast in some organs, limitations on applicable tube voltages, and dependence on patient diameters and scanner output. Sn/Ag filtration increases the effective beam energy by approximately 20-30％. Overall, spectral beam shaping is useful option for non-contrast, high-contrast tasks (e.g., chest and bone) and scenarios requiring repeated scanning.