High-spatial-resolution Monte Carlo simulations of small-animal x-ray fluorescence tomography

2020 ◽  
Author(s):  
Kian Shaker ◽  
Jakob C. Larsson ◽  
Hans M. Hertz
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Small Animal ◽  
Fluorescence Tomography ◽  
X Ray

Low-voltage EDS of magnesium ferrite Dendrites in a FEG-SEM

1996 ◽  
Vol 54 ◽  
pp. 478-479
Author(s):  
Matthew T. Johnson ◽  
Ian M. Anderson ◽  
Jim Bentley ◽  
C. Barry Carter
Keyword(s):  
Monte Carlo ◽  
Quantitative Analysis ◽  
Monte Carlo Simulations ◽  
Cross Section ◽  
Spatial Resolution ◽  
Low Voltage ◽  
Magnesium Ferrite ◽  
X Ray ◽  
Interaction Volume ◽  
Ferrite Spinel

Energy-dispersive X-ray spectrometry (EDS) performed at low (≤ 5 kV) accelerating voltages in the SEM has the potential for providing quantitative microanalytical information with a spatial resolution of ∼100 nm. In the present work, EDS analyses were performed on magnesium ferrite spinel [(MgxFe1−x)Fe2O4] dendrites embedded in a MgO matrix, as shown in Fig. 1. spatial resolution of X-ray microanalysis at conventional accelerating voltages is insufficient for the quantitative analysis of these dendrites, which have widths of the order of a few hundred nanometers, without deconvolution of contributions from the MgO matrix. However, Monte Carlo simulations indicate that the interaction volume for MgFe2O4 is ∼150 nm at 3 kV accelerating voltage and therefore sufficient to analyze the dendrites without matrix contributions.Single-crystal {001}-oriented MgO was reacted with hematite (Fe2O3) powder for 6 h at 1450°C in air and furnace cooled. The specimen was then cleaved to expose a clean cross-section suitable for microanalysis.

scholarly journals High-spatial-resolution x-ray fluorescence tomography with spectrally matched nanoparticles

2018 ◽  
Vol 63 (16) ◽  
pp. 164001 ◽  
Author(s):  
Jakob C Larsson ◽  
Carmen Vogt ◽  
William Vågberg ◽  
Muhammet S Toprak ◽  
Johanna Dzieran ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Fluorescence Tomography ◽  
X Ray

High-spatial-resolution nanoparticle x-ray fluorescence tomography

2016 ◽  
Author(s):  
Jakob C. Larsson ◽  
William Vågberg ◽  
Carmen Vogt ◽  
Ulf Lundström ◽  
Daniel H. Larsson ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Fluorescence Tomography ◽  
X Ray

scholarly journals A Library of Potential Nanoparticle Contrast Agents for X-Ray Fluorescence Tomography Bioimaging

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Yuyang Li ◽  
Kian Shaker ◽  
Jakob C. Larsson ◽  
Carmen Vogt ◽  
Hans M. Hertz ◽  
...  
Keyword(s):  
Contrast Agents ◽  
High Spatial Resolution ◽  
Tumor Imaging ◽  
Small Animal ◽  
Laboratory System ◽  
Fluorescence Tomography ◽  
X Ray ◽  
Tomography System ◽  
Compton Background ◽  
Biological Optimization

Nanoparticles (NPs) have been used as contrast agents for several bioimaging modalities. X-ray fluorescence (XRF) tomography can provide sensitive and quantitative 3D detection of NPs. With spectrally matched NPs as contrast agents, we demonstrated earlier in a laboratory system that XRF tomography could achieve high-spatial-resolution tumor imaging in mice. Here, we present the synthesis, characterization, and evaluation of a library of NPs containing Y, Zr, Nb, Rh, and Ru that have spectrally matched K-shell absorption for the laboratory scale X-ray source. The K-shell emissions of these NPs are spectrally well separated from the X-ray probe and the Compton background, making them suitable for the lab-scale XRF tomography system. Their potential as XRF contrast agents is demonstrated successfully in a small-animal equivalent phantom, confirming the simulation results. The diversity in the NP composition provides a flexible platform for a better design and biological optimization of XRF tomography nanoprobes.

scholarly journals High-Spatial-Resolution Bone Densitometry with Dual-Energy X-ray Absorptiometric Region-free Analysis

Radiology ◽  
2015 ◽  
Vol 275 (1) ◽  
pp. 310-310 ◽  
Author(s):  
Richard M. Morris ◽  
Lang Yang ◽  
Miguel A. Martín-Fernández ◽  
Jose M. Pozo ◽  
Alejandro F. Frangi ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Bone Densitometry ◽  
High Spatial Resolution ◽  
Dual Energy ◽  
X Ray

scholarly journals A Monte Carlo Determination of Dose and Range Uncertainties for Preclinical Studies with a Proton Beam

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1889
Author(s):  
Arthur Bongrand ◽  
Charbel Koumeir ◽  
Daphnée Villoing ◽  
Arnaud Guertin ◽  
Ferid Haddad ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Proton Beam ◽  
Dose Response ◽  
Small Animal ◽  
Absorbed Dose ◽  
Normal Tissue Damage ◽  
Dose Homogeneity ◽  
And Control ◽  
The Impact

Proton therapy (PRT) is an irradiation technique that aims at limiting normal tissue damage while maintaining the tumor response. To study its specificities, the ARRONAX cyclotron is currently developing a preclinical structure compatible with biological experiments. A prerequisite is to identify and control uncertainties on the ARRONAX beamline, which can lead to significant biases in the observed biological results and dose–response relationships, as for any facility. This paper summarizes and quantifies the impact of uncertainty on proton range, absorbed dose, and dose homogeneity in a preclinical context of cell or small animal irradiation on the Bragg curve, using Monte Carlo simulations. All possible sources of uncertainty were investigated and discussed independently. Those with a significant impact were identified, and protocols were established to reduce their consequences. Overall, the uncertainties evaluated were similar to those from clinical practice and are considered compatible with the performance of radiobiological experiments, as well as the study of dose–response relationships on this proton beam. Another conclusion of this study is that Monte Carlo simulations can be used to help build preclinical lines in other setups.

scholarly journals Modular MA-XRF Scanner Development in the Multi-Analytical Characterisation of a 17th Century Azulejo from Portugal

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1913
Author(s):  
Sergio Augusto Barcellos Lins ◽  
Marta Manso ◽  
Pedro Augusto Barcellos Lins ◽  
Antonio Brunetti ◽  
Armida Sodo ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
17Th Century ◽  
Scanning System ◽  
X Ray ◽  
Portable Instruments ◽  
Complementary Techniques ◽  
Non Destructive ◽  
Suitable Technique ◽  
Cobalt Blue

A modular X-ray scanning system was developed, to fill in the gap between portable instruments (with a limited analytical area) and mobile instruments (with large analytical areas, and sometimes bulky and difficult to transport). The scanner has been compared to a commercial tabletop instrument, by analysing a Portuguese tile (azulejo) from the 17th century. Complementary techniques were used to achieve a throughout characterisation of the sample in a complete non-destructive approach. The complexity of the acquired X-ray fluorescence (XRF) spectra, due to inherent sample stratigraphy, has been resolved using Monte Carlo simulations, and Raman spectroscopy, as the most suitable technique to complement the analysis of azulejos colours, yielding satisfactory results. The colouring agents were identified as cobalt blue and a Zn-modified Naples-yellow. The stratigraphy of the area under study was partially modelled with Monte Carlo simulations. The scanners performance has been compared by evaluating the images outputs and the global spectrum.

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