نتایج جستجو برای: tomography scanners x ray computed

تعداد نتایج: 839821  

2014
Julien Pansiot Lionel Revéret Edmond Boyer

This paper considers 3D imaging of moving objects and introduces a technique that exploits visible and x-ray images to recover dense 3D models. While recent methods such as tomography from cone-beam x-ray can advantageously replace more expensive and higher-dose CT scanners, they still require specific equipment and immobilised patients. We investigate an alternative strategy that combines a si...

2015
Taihei Mukaide Atsuo Iida Masatoshi Watanabe Kazuhiro Takada Takashi Noma Qinghui Zhang

We demonstrate a new analytical X-ray computed tomography technique for visualizing and quantifying the mass density of materials comprised of low atomic number elements with unknown atomic ratios. The mass density was obtained from the experimentally observed ratio of the imaginary and real parts of the complex X-ray refractive index. An empirical linear relationship between the X-ray mass att...

Introduction: Crosstalk is a leakage of X-ray or light produced in a matrix of X-ray detectors or array of photodiodes in one element to other elements affecting on image contrast and spatial resolution. In this study, we assessed X-ray crosstalk in a computed tomography (CT) scanner with small detector elements to estimate the effect of various parameters such as X-ray tube voltage, detector e...

2009
Vasilios Skiadas Vasilios Koutoulidis Andreas Koureas Lia Moulopoulos Athanasios Gouliamos

An 18-year-old male patient presented with chronic nonspecific pain of three months located at his left proximal tibia. The patient was admitted to our department for plain X-ray, computed tomography and magnetic resonance imaging examination. Plain X-ray and computed tomography revealed a geographic lytic lesion at the medial aspect of the proximal tibia. Biopsy of the lesion showed telangiect...

Journal: :Photonics 2021

X-ray fluorescence computed tomography (XFCT) is a molecular imaging technique that can be used to sense different elements or nanoparticle (NP) agents inside deep samples tissues. However, XFCT has not been popular tool because it limited sensitivity and spatial resolution. We present benchtop system in which superfine pencil-beam source ring of spectrometers were simulated using GATE (Geant4 ...

2017
Jun Li Wenyin Shi David Andrews Maria Werner-Wasik Bo Lu Yan Yu Adam Dicker Haisong Liu

PURPOSE The study was aimed to compare online 6 degree-of-freedom image registrations of TrueBeam cone-beam computed tomography and BrainLab ExacTrac X-ray imaging systems for intracranial radiosurgery. METHODS Phantom and patient studies were performed on a Varian TrueBeam STx linear accelerator (version 2.5), which is integrated with a BrainLab ExacTrac imaging system (version 6.1.1). The p...

Journal: :Revista Brasileira de Física Médica 2022

A proposed method to obtain the dose for Computed Tomography was evaluated on long a phantom, made of polyethylene. This phantom is 600 mm large. Adopting an empirical characterized function , tendency asymptotical grow by increase scanning length can estimate in infinite single axial rotation x-ray tube. The curve estimated different clinical protocols: tension, pitch, head/body, and center/pe...

2011
Konstantin Ignatyev Peter R.T. Munro Deeph Chana Robert D. Speller Alessandro Olivo

X-ray baggage scanners play a basic role in the protection of airports, customs, and other strategically important buildings and infrastructures. The current technology of baggage scanners is based on x-ray attenuation, meaning that the detection of threat objects relies on how various objects differently attenuate the x-ray beams going through them. This capability is enhanced by the use of du...

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