Trace element analysis in biological samples by using XRF spectrometry with secondary radiation

Cesáreo, R.; Viezzoli, G

doi:10.1088/0031-9155/28/11/002

Cited by 24 publications

(7 citation statements)

References 4 publications

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“…Unfortunately, current methods for measuring elemental concentrations are not compatible with in vivo methods [4], [6], [10]- [18]. NSECT has the potential to non-invasively measure and image elemental concentrations; thereby, it has the potential to identify and map regions of the breast containing elemental abnormalities.…”

Section: Introductionmentioning

confidence: 99%

Design and Development of a High-Energy Gamma Camera for Use With NSECT Imaging: Feasibility for Breast Imaging

Sharma

Tourassi

Kapadia

et al. 2007

IEEE Trans. Nucl. Sci.

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A new spectroscopic imaging technique, Neutron Stimulated Emission Computed Tomography (NSECT), is currently being developed to non-invasively and non-destructively measure and image elemental concentrations within the body. NSECT has potential for use in breast imaging as several studies have shown a link between elemental concentration and tumor status. In NSECT, a region of interest is illuminated with a high-energy (3-5 MeV) beam of neutrons that scatter inelastically with elemental nuclei within the body. The characteristic gamma rays that are emitted as the excited nuclei relax allow the identification of elements and the formation of elemental composition images. This imaging technique requires high-resolution and high-energy gamma spectroscopy; thereby eliminating current scintillation crystal based position sensitive gamma cameras. Instead, we propose to adapt high-energy gamma imaging techniques used in space-based imaging. A High Purity Germanium (HPGe) detector provides high-resolution energy spectra while a rotating modulation collimator (RMC) placed in front of the detector modulates the incoming signal to provide spatial information. Counting the number of gamma events at each collimator rotation angle allows for reconstruction of images. Herein we report on the design and testing of a prototype RMC, a Monte Carlo simulation of this camera, and the use of this simulation tool to access the feasibility of imaging a breast with such a camera. The prototype RMC was tested with a 22 Na point source and verified that the RMC modulates the gamma rays in a predictable manner. The Monte Carlo simulation accurately modeled this behavior. Other simulations were used to accurately reconstruct images of a point source located within a 10 cm cube, suggesting NSECT's potential as a breast imaging method.

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Section: Introductionmentioning

confidence: 99%

Design and Development of a High-Energy Gamma Camera for Use With NSECT Imaging: Feasibility for Breast Imaging

Sharma

Tourassi

Kapadia

et al. 2007

IEEE Trans. Nucl. Sci.

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“…X-ray fluorescence (XRF) analysis is a highly sensitive technique capable of quantifying and identifying an element of interest such as gold by detecting XRF photons emitted from the element (Cesareo and Viezzoli, 1983;Pushie et al, 2014). XRF analysis can be combined with computed tomography (CT) to create a powerful spectroscopic/quantitative x-ray imaging modality known as x-ray fluorescence computed tomography (XFCT), traditionally associated with synchrotron x-ray sources (Rust and Weigelt, 1998;Cesareo and Mascarenhas, 1989).…”

Section: Introductionmentioning

confidence: 99%

A detector’s eye view (DEV)-based OSEM algorithm for benchtop x-ray fluorescence computed tomography (XFCT) image reconstruction

Deng¹,

Ahmed

Jayarathna

et al. 2019

Phys. Med. Biol.

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In this study, we developed a detector's eye view (DEV)-based ordered subsets expectation maximization (OSEM) algorithm for more accurate reconstruction of benchtop x-ray fluorescence computed tomography (XFCT) images. The proposed approach was tested using two sets of benchtop XFCT imaging data derived from a newly performed gold nanoparticle (GNP)containing phantom imaging study and a previously published postmortem benchtop XFCT imaging study of a tumor-bearing mouse injected with GNPs. DEV-based OSEM resulted in higher spatial resolution (up to 20% decrease in the full width at half maximum values of the regions of interest), compared with filtered back-projection (FBP) and traditional OSEM. It also resulted in up to an order of magnitude smaller background noise in the reconstructed images than FBP, while producing consistently less background noise than traditional OSEM.

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“…X-ray fluorescence (XRF) analysis is a well-known technique capable of accurately identifying and quantifying the concentrations of elements [1–3]. Combining it with computed tomography (CT) leads to a unique x-ray imaging modality known as x-ray fluorescence CT (XFCT), traditionally implemented using monochromatic synchrotron x-rays [4–9].…”

Section: Introductionmentioning

confidence: 99%

A Monte Carlo Model of a Benchtop X-Ray Fluorescence Computed Tomography System and Its Application to Validate a Deconvolution-Based X-Ray Fluorescence Signal Extraction Method

Ahmed

Yaşar

Cho

2018

IEEE Trans. Med. Imaging

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In this study, we developed and validated a Geant4-based Monte Carlo (MC) model of an experimental benchtop X-ray fluorescence (XRF) computed tomography (XFCT) system for quantitative imaging of metallic nanoparticles such as gold nanoparticles (GNPs) injected into small animals for preclinical testing of various NP-based diagnostic and therapeutic approaches. Detailed hardware components of the current benchtop XFCT system, including the X-ray source, excitation beam collimation and filtration, custom imaging phantoms with GNP solutions, and single/ring/linear array detectors with custom collimation, were incorporated into the MC model. In conjunction with a known CdTe detector response function, a deconvolution-based XRF signal extraction method was also developed in this study, which enabled complete separation of gold K-shell XRF peaks even when they almost overlapped and facilitated extraction of XRF signals from a broadband Compton scattered photon background. The extracted signal-to-background ratios were comparable with those expected using an ideal detector with high enough energy resolution (e.g., 0.1 keV full-width at half-maximum). Once convoluted with the CdTe detector response function, the MC-calculated spectra for excitation beams or emitted photons and XFCT image spatial resolutions agreed well with those measured experimentally. Thus, the current MC model can be used to optimize the beam/imaging parameters (e.g., beam geometry, excitation X-ray beam energy, and X-ray filter material) as well as the design of critical hardware components (e.g., detector collimators) within the current benchtop XFCT system. Also, the current XRF signal extraction method can relax the usual stringent requirement of detector energy resolution while not degrading the sensitivity of benchtop XFCT.

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Trace element analysis in biological samples by using XRF spectrometry with secondary radiation

Cited by 24 publications

References 4 publications

Design and Development of a High-Energy Gamma Camera for Use With NSECT Imaging: Feasibility for Breast Imaging

Design and Development of a High-Energy Gamma Camera for Use With NSECT Imaging: Feasibility for Breast Imaging

A detector’s eye view (DEV)-based OSEM algorithm for benchtop x-ray fluorescence computed tomography (XFCT) image reconstruction

A Monte Carlo Model of a Benchtop X-Ray Fluorescence Computed Tomography System and Its Application to Validate a Deconvolution-Based X-Ray Fluorescence Signal Extraction Method

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