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Doing quantitative computed tomography (CT) using Bremsstrahlung sources requires an estimate of the spectrum emitted by the X-ray source. One method of beam hardening correction (BHC), as described by Lifton[1], first uses transmission…

Medical Physics · Physics 2025-08-13 Nikhil Deshmukh

Due to the energy-dependent nature of the attenuation coefficient and the polychromaticity of the X-ray source, beam hardening effect occurs when X-ray photons penetrate through an object, causing a nonlinear projection data. When a linear…

Medical Physics · Physics 2018-12-07 Wei Zhao , Dengwang Li , Kai Niu , Wenjian Qin , Hao Peng , Tianye Niu

Beam hardening (BH) is one of the major artifacts that severely reduces the quality of Computed Tomography (CT) imaging. In a polychromatic X-ray beam, since low-energy photons are more preferentially absorbed, the attenuation of the beam…

Image and Video Processing · Electrical Eng. & Systems 2022-03-10 Ammar Alsaffar , Kaicong Sun , Sven Simon

Purpose: To evaluate a proposed method to reconstruct CT numbers that accurately mimic conventional CT numbers from spectral CT data, as would have been produced by a conventional system without effects of beam hardening. Approach: We…

Medical Physics · Physics 2022-08-10 Fredrik Grönberg , Hans Bornefalk

This work is dedicated to computer modeling of the parameters of a tungsten converter for studying the processes of radiation damage during the interaction of ionizing radiation with solutions of organic dyes. Simulation was carried out in…

Computational Physics · Physics 2021-12-15 Tetiana Malykhina , Vladimir Kovtun , Valentin Kasilov , Sergey Gokov

We present new methods for lensing reconstruction from CMB temperature fluctuations which have smaller mean-field and reconstruction noise bias corrections than current lensing estimators, with minimal loss of signal-to-noise. These biases…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-08 Toshiya Namikawa , Duncan Hanson , Ryuichi Takahashi

Scanning Transmission Electron Microscopy (STEM) has become the main stay for materials characterization on atomic level, with applications ranging from visualization of localized and extended defects to mapping order parameter fields. In…

Instrumentation and Detectors · Physics 2019-01-15 Xin Li , Ondrej Dyck , Sergei V. Kalinin , Stephen Jesse

Scanning Transmission Electron Microscopy (STEM) offers high-resolution images that are used to quantify the nanoscale atomic structure and composition of materials and biological specimens. In many cases, however, the resolution is limited…

Signal Processing · Electrical Eng. & Systems 2021-12-23 Daniel Nicholls , Alex Robinson , Jack Wells , Amirafshar Moshtaghpour , Mounib Bahri , Angus Kirkland , Nigel Browning

We discuss a method to reconstruct two-dimensional proton bunch densities using vertex distributions accumulated during LHC beam-beam scans. The $x$-$y$ correlations in the beam shapes are studied and an alternative luminosity calibration…

High Energy Physics - Experiment · Physics 2019-04-10 Markus Klute , Catherine Medlock , Jakob Salfeld-Nebgen

The mathematical foundation of X-ray CT is based on the assumption that by measuring the attenuation of X-rays passing through an object, one can recover the integrals of the attenuation coefficient $\mu(x)$ along a sufficiently rich family…

Numerical Analysis · Mathematics 2025-05-07 Alexander Katsevich

Quantifying material mass and electron density from computed tomography (CT) reconstructions can be highly valuable in certain medical practices, such as radiation therapy planning. However, uniquely parameterising the X-ray attenuation in…

Medical Physics · Physics 2019-04-30 Jonathan H. Mason , Alessandro Perelli , William H. Nailon , Mike E. Davies

Sample thickness is an important parameter in transmission electron microscopy (TEM) imaging, for interpreting image contrast and understanding the relationship between properties and microstructure. In this study, we introduce a method for…

Materials Science · Physics 2021-11-15 Pengfei Nan , Zhiyao Liang , Yue Zhang , Yangrui Liu , Dongsheng Song , Binghui Ge

This paper provides a fast and patient-specific scatter artifact correction method for cone-beam computed tomography (CBCT) used in image-guided interventional procedures. Due to increased irradiated volume of interest in CBCT imaging,…

Medical Physics · Physics 2015-01-20 Wei Zhao , Stephen Brunner , Kai Niu , Sebastian Schafer , Kevin Royalty , Guang-Hong Chen

It is common, in deconvolution problems, to assume that the measurement errors are identically distributed. In many real-life applications, however, this condition is not satisfied and the deconvolution estimators developed for…

Statistics Theory · Mathematics 2008-12-18 Aurore Delaigle , Alexander Meister

Aberration corrected scanning transmission electron microscopes (STEM) enable to determine local strain fields, composition and bonding states at atomic resolution. The precision to locate atomic columns is often obstructed by scan…

Applied Physics · Physics 2019-01-16 Benjamin Berkels , Christian H. Liebscher

Computed tomography (CT) images are frequently degraded by acquisition artifacts, including noise, blur, streaking, aliasing, and metal artifacts. Yet CT enhancement is still largely evaluated using image quality metrics with limited…

This paper proposes a sinogram consistency learning method to deal with beam-hardening related artifacts in polychromatic computerized tomography (CT). The presence of highly attenuating materials in the scan field causes an inconsistent…

Medical Physics · Physics 2019-06-06 Hyung Suk Park , Sung Min Lee , Hwa Pyung Kim , Jin Keun Seo

Flatbed scanners have emerged as promising devices for high-resolution, single-image material capture. However, existing approaches assume very specific conditions, such as uniform diffuse illumination, which are only available in certain…

We have demonstrated the use of the bremsstrahlung radiation in energy dispersive x-ray fluorescence technique as a tool to perform non-destructive elemental analysis of solid samples employed in inter-disciplinary science research. The…

Instrumentation and Detectors · Physics 2023-03-06 Soumya Chatterjee , Sumana Ghosh , D. Mitra

Different technical and physical factors may affect the image quality reconstructed using a Computed Tomography system. We have developed and designed a 2D Gamma Computed Tomography set up to study the effect of some physical parameters.…

Instrumentation and Detectors · Physics 2022-08-19 Kajal Kumari , Mayank Goswami
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