Image quality determination of a novel digital detector for X-ray imaging and cone -beam computed tomography applications
Affiliation
Research Department of Tissue and Energy, Division of Surgery and Interventional Science, University College London, LondonIssue Date
2020
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The demand for adequate image quality with low radiation doses for patients has greatly increased. This is especially true in the case of position verification in radiotherapy which requires a high number of images per patient. This study presents a physical characterisation of a new clinical detector named “Lassena (CsI)” based on a thick layer of structured thallium activated caesium iodide and complementary metal-oxide semiconductor technology with active pixel sensor architecture for general X-ray imaging and cone-beam computed tomography (CBCT) applications. We made a critical appraisal of its performance for the first time and determined its signal transfer property (STP) and its detective quantum efficiency (DQE) by acquiring the pre-sampling modulation transfer function (pMTF) and normalised noise power spectrum (NNPS) in addition to the dark current calculation. The investigation was conducted with the application of three X-ray beam qualities: (50 kV (RQA3), 70 kV (RQA5) and 90 kV (RQA7)) in compliance with the International Electrotechnical Commission (IEC 62220-1(2003)) standard. The STP was found to be linear with the coefficient of determination (R²) more than 0.9995 in all cases. The spatial resolution and NNPS results led to acceptable DQE values at all energies; in particular the DQE values at 0.5 line pairs per mm (DQE(0.5)) which were 0.46 for RQA3, 0.52-0.56 for RQA5 and 0.55-0.59 for RQA7. Lastly, the dark current was 2.51 pA/cm² for a 50?m pixel pitch. For CBCT applications, Lassena (CsI) showed very promising results.Citation
Alzahrani H, Richards S, Sedgwick I, Seller P, Konstantinidis A, Royle G, et al. Image quality determination of a novel digital detector for X-ray imaging and cone-beam computed tomography applications. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 2020;968:163914.Journal
Nuclear Instruments & Methods in Physics Research Section a-Accelerators Spectrometers Detectors and Associated EquipmentDOI
10.1016/j.nima.2020.163914PubMed ID
No PMIDAdditional Links
https://dx.doi.org/10.1016/j.nima.2020.163914Type
Meetings and ProceedingsLanguage
enae974a485f413a2113503eed53cd6c53
10.1016/j.nima.2020.163914