Results 111 to 120 of about 1,044,520 (358)

Anomalous scaling law for noise variance and spatial resolution in differential phase contrast computed tomography [PDF]

, 2010
In conventional absorption based x-ray computed tomography (CT), the noise variance in reconstructed CT images scales with spatial resolution following an inverse cubic relationship. Without reconstruction, in x-ray absorption radiography, the noise variance scales as an inverse square with spatial resolution.
arxiv   +1 more source

Assessing HyperSight iterative CBCT for dose calculation in online adaptive radiotherapy for pelvis and breast patients compared to synthetic CT

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Purpose/objectives Recent technological advancements have increased efficiency for clinical deliverability of online‐adaptive‐radiotherapy (oART). Previous cone‐beam‐computed‐tomography (CBCT) generations lacked the ability to provide reliable Hounsfield‐units (HU), thus requiring oART workflows to rely on synthetic‐CT (sCT) images derived ...
Jingwei Duan, Joel A. Pogue, Dennis N. Stanley, Sui Shen, Natalie N. Viscariello, Carlos E. Cardenas, Richard A. Popple, Joseph Harms   +7 more
wiley   +1 more source

Multi-view polarimetric scattering cloud tomography and retrieval of droplet size [PDF]

arXiv, 2020
Tomography aims to recover a three-dimensional (3D) density map of a medium or an object. In medical imaging, it is extensively used for diagnostics via X-ray computed tomography (CT). Optical diffusion tomography is an alternative to X-ray CT that uses multiply scattered light to deliver coarse density maps for soft tissues.
arxiv  

Stored Luminescence Computed Tomography [PDF]

, 2013
The phosphor nanoparticles made of doped semiconductors, pre-excited by well-collimated X-ray radiation, were recently reported for their light emission upon NIR light stimulation. The characteristics of X-ray energy storage and NIR stimulated emission is highly desirable to design targeting probes and improve molecular and cellular imaging.
arxiv   +1 more source

Evaluating the use of diagnostic CT with flattening filter free beams for palliative radiotherapy: Dosimetric impact of scanner calibration variability

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Purpose Palliative radiotherapy comprises a significant portion of the radiation treatment workload. Volumetric‐modulated arc therapy (VMAT) improves dose conformity and, in conjunction with flattening filter free (FFF) delivery, can decrease treatment times, both of which are desirable in a population with a high probability of retreatment ...
Madeleine L. Van de Kleut, Lesley A. Buckley, Elsayed S. M. Ali   +2 more
wiley   +1 more source

Evaluation of the effect of metal stents on dose perturbation in the carbon beam irradiation field

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Propose Carbon ion therapy is indicated for cases in which stents have been inserted, such as bile ducts, but the effect of metal stents on carbon ion therapy is unclear. In this study, the dose perturbation of carbon ion therapy caused by metallic bile duct stents was evaluated by dosimetry. Materials and methods Five different types of metal
Yuya Miyasaka, Tetsuya Ishizawa, Yoshihito Nawa, Hikaru Souda, Shohei Kawashiro, Hongbo Chai, Miyu Ishizawa, Hiraku Sato, Takeo Iwai   +8 more
wiley   +1 more source

X‐ray computed tomography and its potential in ecological research: A review of studies and optimization of specimen preparation

Ecology and Evolution, 2018
Imaging techniques are a cornerstone of contemporary biology. Over the last decades, advances in microscale imaging techniques have allowed fascinating new insights into cell and tissue morphology and internal anatomy of organisms across kingdoms ...
Yeisson Gutiérrez, David Ott, M. Töpperwien, T. Salditt, C. Scherber   +4 more
semanticscholar   +1 more source

Undersampled dynamic X-ray tomography with dimension reduction Kalman filter [PDF]

arXiv, 2018
In this paper, we consider prior-based dimension reduction Kalman filter for undersampled dynamic X-ray tomography. With this method, the X-ray reconstructions are parameterized by a low-dimensional basis. Thus, the proposed method is a) computationally very light; and b) extremely robust as all the computations can be done explicitly.
arxiv  

Stereotactic radiotherapy for metastatic brain tumors: A comparative analysis of dose distributions among VMAT, Helical TomoTherapy, CyberKnife, Gamma Knife, and ZAP‐X

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract This study evaluates various radiotherapy techniques for treating metastatic brain tumor (BT), focusing on non‐coplanar volumetric modulated arc radiotherapy (NC‐VMAT), coplanar VMAT (C‐VMAT), Helical TomoTherapy (HT), CyberKnife (CK), Gamma Knife (GK), and ZAP‐X.
Toshihiro Suzuki, Masahide Saito, Ryutaro Nomura, Hikaru Nemoto, Naoto Yanagisawa, Ryuma Sawada, Zennosuke Mochizuki, Naoki Sano, Hiroshi Onishi, Hiroshi Takahashi   +9 more
wiley   +1 more source

Exploring surface‐guided systems for intelligent breathing‐adapted four‐dimensional computed tomography: A comparison to infrared‐based reflective marker systems

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Purpose This study evaluates the technical feasibility of adapting a surface monitoring system, designed for conventional four‐dimensional computed tomography (4DCT), to an intelligent, breathing‐adapted 4DCT and examines its potential to expand the currently limited range of supported surrogate systems.
Niklas Lackner, Andre Karius, Rainer Fietkau, Christoph Bert, Juliane Szkitsak   +4 more
wiley   +1 more source