Characterization of a Pixelated Cadmium Telluride Detector System Using a Polychromatic X-Ray Source and Gold Nanoparticle-Loaded Phantoms for Benchtop X-Ray Fluorescence Imaging
| Autor: | Foiez Ahmed, Sandun Jayarathna, Yonggang Cui, Sang Hyun Cho, Liam O'ryan, Hem Moktan |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Photon General Computer Science X-ray fluorescence 01 natural sciences Article 030218 nuclear medicine & medical imaging Charge sharing HEXITEC 03 medical and health sciences 0302 clinical medicine Optics 0103 physical sciences General Materials Science Pixelated CdTe detector x-ray fluorescence 010308 nuclear & particles physics business.industry benchtop x-ray fluorescence computed tomography Detector Resolution (electron density) General Engineering X-ray Cadmium telluride photovoltaics Full width at half maximum gold nanoparticles lcsh:Electrical engineering. Electronics. Nuclear engineering business lcsh:TK1-9971 |
| Zdroj: | IEEE Access IEEE Access, Vol 9, Pp 49912-49919 (2021) |
| ISSN: | 2169-3536 |
| Popis: | Pixelated semi-conductor detectors providing high energy resolution enable parallel acquisition of x-ray fluorescence (XRF) signals, potentially leading to performance enhancement of benchtop XRF imaging or computed tomography (XFCT) systems utilizing ordinary polychromatic x-ray sources. However, little is currently known about the characteristics of such detectors under typical operating conditions of benchtop XRF imaging/XFCT. In this work, a commercially available pixelated cadmium telluride (CdTe) detector system, HEXITEC (High Energy X-ray Imaging Technology), was characterized to address this issue. Specifically, HEXITEC was deployed into our benchtop cone-beam XFCT system, and used to detect gold $\text{K}\alpha $ XRF photons from gold nanoparticle (GNP)–loaded phantoms. To facilitate the detection of XRF photons, various parallel-hole stainless steel collimators were fabricated and coupled with HEXITEC. A pixel-by-pixel spectrum merging algorithm was introduced to obtain well-defined XRF + scatter spectra with parallel-hole collimators. The effect of charge sharing addition (CSA) and discrimination (CSD) algorithms was also investigated for pixel-level CS correction. Finally, the detector energy resolution, in terms of the full-width at half-maximum (FWHM) values at two gold $\text{K}\alpha $ XRF peaks (~68 keV), was also determined. Under the current experimental conditions, CSD provided the best energy resolution of HEXITEC (~1.05 keV FWHM), compared with CSA and no CS correction. This FWHM value was larger (by up to ~0.35 keV) than those reported previously for HEXITEC (at ~60 keV Am-241 peak) and single-crystal CdTe detectors (at two gold $\text{K}\alpha $ XRF peaks). This investigation highlighted characteristics of HEXITEC as well as the necessity for application-specific detector characterization. |
| Databáze: | OpenAIRE |
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