High-DQE EPIDs based on thick, segmented BGO and CsI:Tl scintillators: performance evaluation at extremely low dose
Abstract
PURPOSE: Electronic portal imaging devices (EPIDs) based on active matrix, flat-panel imagers (AMFPIs) have become the gold standard for portal imaging and are currently being investigated for megavoltage cone-beam computed tomography (CBCT) and cone-beam digital tomosynthesis (CBDT). However, the practical realization of such volumetric imaging techniques is constrained by the relatively low detective quantum efficiency (DQE) of AMFPI-based EPIDs at radiotherapy energies, approximately 1% at 6 MV. In order to significantly improve DQE, the authors are investigating thick, segmented scintillators, consisting of 2D matrices of scintillating crystals separated by septal walls.
METHODS: A newly constructed segmented BGO scintillator (11.3 mm thick) and three segmented CsI:Tl scintillators (11.4, 25.6, and 40.0 mm thick) were evaluated using a 6 MV photon beam. X-ray sensitivity, modulation transfer function, noise power spectrum, DQE, and phantom images were obtained using prototype EPIDs based on the four scintillators.
RESULTS: The BGO and CsI:Tl prototypes were found to exhibit improvement in DQE ranging from approximately 12 to 25 times that of a conventional AMFPI-based EPID at zero spatial frequency. All four prototype EPIDs provide significantly improved contrast resolution at extremely low doses, extending down to a single beam pulse. In particular, the BGO prototype provides contrast resolution comparable to that of the conventional EPID, but at 20 times less dose,…
Read the paper
Related studies
- Developing high safety Li-metal anodes for future high-energy Li-metal batteries: strategies and perspectives
- Structure and Energy Transfer in Photosystems of Oxygenic Photosynthesis
- Ground- and Space-Based Gamma-Ray Astronomy
- Energy Functions in De Novo Protein Design: Current Challenges and Future Prospects
- Electronic structure of ions and molecules in solution: a view from modern soft X-ray spectroscopies
- Arising 2D Perovskites for Ionizing Radiation Detection
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.