TY - JOUR
T1 - 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
AU - Jayarathna, Sandun
AU - Ahmed, Md Foiez
AU - O’Ryan, Liam
AU - Moktan, Hem
AU - Cui, Yonggang
AU - Cho, Sang Hyun
N1 - Publisher Copyright:
© 2021 American Institute of Physics Inc.. All rights reserved.
PY - 2021
Y1 - 2021
N2 - 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 Kα 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 Kα 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 Kα XRF peaks). This investigation highlighted characteristics of HEXITEC as well as the necessity for application-specific detector characterization.
AB - 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 Kα 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 Kα 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 Kα XRF peaks). This investigation highlighted characteristics of HEXITEC as well as the necessity for application-specific detector characterization.
KW - Benchtop x-ray fluorescence computed tomography
KW - Gold nanoparticles
KW - HEXITEC
KW - Pixelated CdTe detector
KW - X-ray fluorescence
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U2 - 10.1109/ACCESS.2021.3069368
DO - 10.1109/ACCESS.2021.3069368
M3 - Article
C2 - 33996343
AN - SCOPUS:85107219209
SN - 2169-3536
VL - 9
SP - 49912
EP - 49919
JO - IEEE Access
JF - IEEE Access
M1 - 9388666
ER -