CT Systems

Flohr, Thomas

doi:10.1007/s40134-012-0005-5

Cited by 26 publications

(19 citation statements)

References 53 publications

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“…In this study, the experiments were performed at the BL1U beamline located at the UVSOR-III Synchrotron Radiation Facility [15], [22]. The developed NRF-CT system was based on a first-generation CT scanner [23]. Fig.…”

Section: Methodsmentioning

confidence: 99%

Selective Isotope CT Imaging Based on Nuclear Resonance Fluorescence Transmission Method

Ali

Ohgaki

Zen

et al. 2020

IEEE Trans. Nucl. Sci.

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The isotope selectivity of computed tomography (CT) imaging based on nuclear resonance fluorescence (NRF) transmission method using a quasi-monochromatic laser Compton scattering (LCS) gamma-ray beam in the MeV region was demonstrated at the Ultra Violet Synchrotron Orbital Radiation-III (UVSOR-III) Synchrotron Radiation Facility (Institute of Molecular Science, National Institute of Natural Science) for two enriched lead isotope rods (206 Pb and 208 Pb) implanted in an aluminum cylinder. Since these two rods show the same gamma-ray attenuation in atomic processes, it is impossible to differentiate between them using a standard Gamma-CT technique based on atomic attenuation of gamma rays. The LCS gamma-ray beam had a maximum energy of 5.528 MeV and an intensity of approximately 5.5 photons/s/eV at the resonance energy (J π = 1 − at 5.512 MeV in 208 Pb). A lead collimator with a hole diameter of 1 mm was used to define the size of the LCS gamma-ray beam at the CT target. The CT image of the 208 Pb rod was selectively obtained with a 2-mm pixel size resolution, which was determined by the horizontal step size of the CT stage. Index Terms-Computed tomography (CT), isotope distribution, laser Compton scattering (LCS) gamma-ray beam, nuclear resonance fluorescence (NRF). I. INTRODUCTION N ONDESTRUCTIVE assay (NDA) technology, which is used to identify specific isotopes in a substance,

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Section: Methodsmentioning

confidence: 99%

Selective Isotope CT Imaging Based on Nuclear Resonance Fluorescence Transmission Method

Ali

Ohgaki

Zen

et al. 2020

IEEE Trans. Nucl. Sci.

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“…However, a wider detector z-coverage screening applied may increase radiation scattering. Scattered radiation can cause hypodense artefacts, affect the stability of the CT number, and the scatter-induced noise in the images may decrease the CNR [44].…”

Section: Discussionmentioning

confidence: 99%

Evaluation of Organ Dose and Image Quality Metrics of Pediatric CT Chest-Abdomen-Pelvis (CAP) Examination: An Anthropomorphic Phantom Study

et al. 2021

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The aim of this study is to investigate the impact of CT acquisition parameter setting on organ dose and its influence on image quality metrics in pediatric phantom during CT examination. The study was performed on 64-slice multidetector CT scanner (MDCT) Siemens Definition AS (Siemens Sector Healthcare, Forchheim, Germany) using various CT CAP protocols (P1–P9). Tube potential for P1, P2, and P3 protocols were fixed at 100 kVp while P4, P5, and P6 were fixed at 80 kVp with used of various reference noise values. P7, P8, and P9 were the modification of P1 with changes on slice collimation, pitch factor, and tube current modulation (TCM), respectively. TLD-100 chips were inserted into the phantom slab number 7, 9, 10, 12, 13, and 14 to represent thyroid, lung, liver, stomach, gonads, and skin, respectively. The image quality metrics, signal to noise ratio (SNR) and contrast to noise ratio (CNR) values were obtained from the CT console. As a result, this study indicates a potential reduction in the absorbed dose up to 20% to 50% along with reducing tube voltage, tube current, and increasing the slice collimation. There is no significant difference (p > 0.05) observed between the protocols and image metrics.

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“…The first generation of CT scanners [7,[16][17][18]] operated as follows. The X-ray pencil beam was measured by a single detector, and the X-ray tube and detector moved together (translation movement).…”

Section: Developments Of Computed Tomography Scannermentioning

confidence: 99%

Basic Physical Principles and Clinical Applications of Computed Tomography

Jung

2021

Progress in Medical Physics

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The evolution of X-ray computed tomography (CT) has been based on the discovery of X-rays, the inception of the Radon transform, and the development of X-ray digital data acquisition systems and computer technology. Unlike conventional X-ray imaging (general radiography), CT reconstructs cross-sectional anatomical images of the internal structures according to X-ray attenuation coefficients (approximate tissue density) for almost every region in the body. This article reviews the essential physical principles and technical aspects of the CT scanner, including several notable evolutions in CT technology that resulted in the emergence of helical, multidetector, cone beam, portable, dual-energy, and phase-contrast CT, in integrated imaging modalities, such as positronemission-tomography一CT and single-photon-emission-computed-tomography一CT, and in clinical applications, including image acquisition parameters, CT angiography, image adjustment, versatile image visualizations, volumetric/surface rendering on a computer workstation, radiation treatment planning, and target localization in radiotherapy. The understanding of CT characteristics will provide more effective and accurate patient care in the fields of diagnostics and radiotherapy, and can lead to the improvement of image quality and the optimization of exposure doses.

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CT Systems

Cited by 26 publications

References 53 publications

Selective Isotope CT Imaging Based on Nuclear Resonance Fluorescence Transmission Method

Selective Isotope CT Imaging Based on Nuclear Resonance Fluorescence Transmission Method

Evaluation of Organ Dose and Image Quality Metrics of Pediatric CT Chest-Abdomen-Pelvis (CAP) Examination: An Anthropomorphic Phantom Study

Basic Physical Principles and Clinical Applications of Computed Tomography

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