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We introduce theoretically and demonstrate experimentally a contrast transfer function based phase retrieval algorithm that reconstructs the projected thickness of an homogeneous sample using a polychromatic x-ray source. We show excellent quantitative recovery of test samples in 2D using a synchrotron source with significant harmonic contamination, and in 3D using a laboratory source.
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http://dx.doi.org/10.1364/OE.19.008127 | DOI Listing |
AJR Am J Roentgenol
September 2025
Department of Radiology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.
Patients with inflammation-associated coronary artery disease (CAD) may exhibit rapid progression and require regular coronary imaging. To evaluate the diagnostic performance of spectral photon-counting detector (PCD) coronary CTA with reduced radiation and contrast media doses for detecting coronary stenosis and in-stent restenosis in patients with inflammation-associated CAD. This prospective study enrolled patients with inflammation-associated CAD from January 2023 to March 2024.
View Article and Find Full Text PDFNucl Instrum Methods Phys Res A
March 2025
Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
x-ray fluorescence (XRF) photons induced from gold nanoparticles (GNPs) after being irradiated by an x-ray beam allow for highly sensitive XRF imaging/computed tomography (XFCT) of biological samples containing GNPs at low concentrations on the order of parts-per-million (ppm). The primary goal of this Monte Carlo (MC) study was to investigate the feasibility of upgrading an existing experimental benchtop XRF/XFCT imaging setup adopting a single silicon drift detector (SDD), developed based on the aforementioned concept (often known as XFCT), by deploying another SDD within the same setup. Specifically, an MC model of the original single SDD XFCT setup, along with a filtered 62 kVp polychromatic x-ray beam, was developed using the Geant4 MC toolkit, and added with a second SDD at an equidistance of 11 cm from the isocenter on the opposite side.
View Article and Find Full Text PDFSci Rep
August 2025
Institute of Theoretical and Applied Mechanics, Czech Academy of Sciences, Prosecka 809/76, 190 00, Prague, Czech Republic.
In this work, an in-situ study of phase transitions in low-carbon steel is presented. The phase changes were monitored by the transmission energy dispersive X-ray diffraction technique during the heating, annealing and quenching cycle of the sample under standard laboratory conditions. During energy dispersive X-ray diffraction, the sample volume was transmitted with a pencil beam generated by a standard polychromatic X-ray tube without any spectral filtering.
View Article and Find Full Text PDFPhys Med Biol
August 2025
Department of Radiation Oncology, Mayo Clinic in Florida, Jacksonville, FL 32224, United States of America.
This study aims to develop and validate a pencil beam (PB) algorithm for computing Mayo Clinic Florida microdosimetric kinetic model (MCF MKM)-based relative biological effectiveness (RBE) weighted doses in carbon-ion radiotherapy (CIRT), and to compare its accuracy and efficiency against Monte Carlo (MC) simulations using real patient computed tomography (CT) data.A PB algorithm was implemented to calculate both physical and microdosimetric parameters-using the abridged microdosimetry distribution methodology (AMDM)-for the MCF MKM model, and subsequently the RBE-weighted dose. Four clinical cases (brain, head and neck, lung and prostate) were planned in-house and computed using the PB algorithm and tool for particle simulation (TOPAS) MC simulations.
View Article and Find Full Text PDFAnn Biomed Eng
July 2025
Research Unit of Health Sciences and Technology, University of Oulu, Aapistie 5A, 90220, Oulu, Finland.
Purpose: Image inaccuracies and distortions are amplified in cone-beam computed tomography (CBCT), with beam hardening and metal artifacts being particularly pronounced, thereby complicating diagnostic interpretation. An approach, combining dual-energy CBCT based projection-domain material decomposition with virtual monochromatic imaging (VMI) technique, was leveraged to mitigate beam hardening artifacts originating from dental restorative and prosthetic materials on a diagnostic CBCT scanner in a phantom setting.
Methods: Severe artifact-causing dental restorative and prosthetic materials were identified from the literature and six of them were selected for the study.