Download or read book Construction and Evaluation of Differential Phase contrast Cone Beam CT Imaging System written by Jiangkun Liu and published by . This book was released on 2015 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: "When X-rays travel through an object, both the intensity and phase status are varied. The amount of variation depends on the attenuation coefficients and phase coefficients of the materials that the object consists of. In recent years, cone beam breast computed tomography (CBBCT) has emerged as a cutting-edge X-ray imaging modality by reconstructing the attenuation contrast. It is an effective method for screening and diagnosis for breast cancer by providing isotropic three-dimensional images with high resolution and high contrast-to-noise ratio (CNR). However, because the variation of attenuation coefficients among soft tissues is subtle, CBBCT is limited in further characterizing breast lesions. Phase contrast CT technology has been attracting research interests recently. It provides new insight into an object by imaging the phase coefficient, which is more sensitive than the attenuation coefficient. Therefore, it has the potential to overcome the limitations of CBBCT and deliver complementary information. Several phase contrast imaging methods have been developed in the past years. However, the requirement of a coherent X-ray source with a sufficiently small dimension impairs their application as a standard method in hospital-based medical imaging. In this thesis, a grating-based bench-top differential phase contrast cone beam CT (DPC-CBCT) system was designed and constructed. Based on the attenuation-based CBCT imaging system setup, it deploys three more major components: a source grating, a phase grating and an analyzer grating. The source grating enables the system to use a hospital-grade X-ray tube and together they provide sufficient X-ray output power and spatial coherence. The phase grating and the analyzer grating transform the phase shift into intensity contrast based on Talbot interferometry so that a high-resolution detector is not necessary. One of the major challenges of the system construction is grating fabrication because of their high aspect ratio and high precision requirements. This work presents designs for robust recipes that produced gratings meeting our demanding criteria. Another challenge is that the system requires highly precise grating alignment to produce the best contrast effect. An effective method is presented in this work that aligns the phase grating the analyzer grating precisely. The second part of this thesis is to evaluate our DPC-CBCT imaging system in terms of uniformity, CNR, noise property and contrast resolution using a cylinder phantom. As the field of view of the imaging system is limited due to the current grating fabrication technique, it is necessary to investigate the performance of volume of interest (VOI) imaging. The VOI imaging experiment was carried out by scanning a large cylinder phantom. In order to evaluate the performance of DPC-CBCT on actual soft tissues, human breast specimen and small animal experiments were carried out. Phantom experiment results indicate that, compared with attenuation imaging, phase contrast imaging provides higher CNR and contrast resolution. However, in specimen and small animal experiments, phase contrast image quality was greatly degraded. The coherence property of an X-ray beam is critical in phase contrast imaging because the image formation mechanism is based on X-ray beam diffraction. Inhomogeneous objects, such as bones and soft tissues, have a large amount of internal density fluctuations or small structures on a micrometer scale. These small structures produce strong small-angle scattering and greatly reduce the coherence of X-ray beams reaching the detector. In order to evaluate the coherence loss caused by an object quantitatively, the last part of this thesis introduces dark-field imaging, which forms an image by computing small-angle scattering power. Dark-field imaging is also based on grating interferometry and the data can be obtained from the same scan with phase contrast imaging. It can be used to characterize the distribution of micro-structures and to investigate coherence loss in DPC-CBCT imaging. Besides coherence loss, several other factors affect the performance of DPC-CBCT, such as polychromatic X-ray spectrum and imperfect gratings. We believe that phase contrast imaging has the potential to be a more powerful imaging tool and more work will be dedicated to the improvement of DPC-CBCT"--Pages vi-viii.
Download or read book Feasibility Study of Phase contrast Cone Beam CT Imaging Systems written by Weixing Cai and published by . This book was released on 2009 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cone beam X ray Phase Contrast Tomography of Biological Samples written by Matthias Bartels and published by Universitätsverlag Göttingen. This book was released on 2013 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three-dimensional information of entire objects can be obtained by the remarkable technique of computed tomography (CT). In combination with phase sensitive X-ray imaging high contrast for soft tissue structures can be achieved as opposed to CT based on classical radiography. In this work biological samples ranging from micrometer sized single cells over multi-cellular nerve tissue to entire millimeter sized organs are investigated by use of cone-beam propagationbased X-ray phase contrast. Optimization with respect to contrast, resolution and field of view is achieved by addressing instrumentation, sample preparation and phase reconstruction techniques. By using laboratory sources functional soft tissue within the bony capsule of mouse cochleae is visualized in 3D with unprecedented image quality. At synchrotron storage rings the technique reveals more than 1000 axons running in parallel within a mouse nerve and enables doseefficient three-dimensional cellular imaging as well as two-dimensional imaging at high resolutions below 50 nm.
Download or read book Cone Beam CT and 3D imaging written by Pietro Caruso and published by Springer Science & Business Media. This book was released on 2013-09-24 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cone beam computed tomography (CBCT) has become the standard of reference in dental imaging. The distribution of CBCT devices is increasingly wide, and the number of required examinations is constantly growing. In this setting, it is now essential that medical and technical staff receive specific training in the use of CBCT and that technical guidelines for CBCT examinations are established. This clearly structured book on CBCT will be an ideal aid in daily clinical practice. It clearly explains basic CBCT anatomy, examination technique, and the use of 3D reformatting software. A wide range of cases are presented, covering the most frequent and relevant conditions and pathologies, including dental anomalies, inflammatory and degenerative disease, tumors, and implants.
Download or read book Cone Beam Computed Tomography written by Chris C. Shaw and published by Taylor & Francis. This book was released on 2014-02-14 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conventional computed tomography (CT) techniques employ a narrow array of x-ray detectors and a fan-shaped x-ray beam to rotate around the patient to produce images of thin sections of the patient. Large sections of the body are covered by moving the patient into the rotating x-ray detector and x-ray source gantry. Cone beam CT is an alternative technique using a large area detector and cone-shaped x-ray beam to produce 3D images of a thick section of the body with one full angle (360 degree or 180 degree plus detector coverage) rotation. It finds applications in situations where bulky, conventional CT systems would interfere with clinical procedures or cannot be integrated with the primary treatments or imaging systems. Cone Beam Computed Tomography explores the past, present, and future state of medical x-ray imaging while explaining how cone beam CT, with its superior spatial resolution and compact configuration, is used in clinical applications and animal research. The book: Supplies a detailed introduction to cone beam CT, covering basic principles and applications as well as advanced techniques Explores state-of-the-art research and future developments while examining the fundamental limitations of the technology Addresses issues related to implementation and system characteristics, including image quality, artifacts, radiation dose, and perception Reviews the historical development of medical x-ray imaging, from conventional CT techniques to volumetric 3D imaging Discusses the major components of cone beam CT: image acquisition, reconstruction, processing, and display A reference work for scientists, engineers, students, and imaging professionals, Cone Beam Computed Tomography provides a solid understanding of the theory and implementation of this revolutionary technology.
Download or read book Evaluation of In room Cone beam CT Imaging Techniques Compared to CT for Dose Calculation written by Sherry A. Leeper and published by . This book was released on 2009 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computed Tomography written by Willi Kalender and published by Publicis. This book was released on 2000-11-23 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book provides a comprehensive and user-friendly description of the theoretical and technical essentials of computed tomography (CT), an imaging technique used extensively by the medical community." --Book Jacket.
Download or read book Evaluation of Cone Beam Computed Tomography Enhancement Using a Liver Specific Contrast Agent For Stereotactic Body Radiation Therapy Guidance written by John Lincoln and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study evaluated contrast enhancement provided by Gadoxetate Disodium, a liver specific contrast agent. Image quality from cone-beam computed tomography was benchmarked against helical fan-beam computed tomography for comparison in cylindrical and ellipsoidal geometries. Concentrations were diluted to 0.0125 - 0.1 mmol/kg corresponding to expected physiological concentrations in the liver. CBCT imaging parameters tube voltage, tube current, and filtration were investigated on board a TrueBeam STx linear accelerator. All parameters were optimized according to the contrast-noise ratio, following the Rose criterion. Acceptable combinations of contrast dose, tube voltage, tube exposure-time product, and filtration gave CNR greater than three. This was found in a range of expected concentrations from 0.025 to 0.1 mmol/kg for a tube voltage of 100 kV, half-fan bowtie filtration, and exposures between 2025 and 5085 mAs. This research provides optimized pre-clinical dosing information and imaging parameters to use Gadoxetate Disodium in a clinical trial with CBCT.
Download or read book Three dimensional Image Quality Evaluation and Improvement in Flat panel Detector Based Cone beam CT Imaging written by Yan Zhang and published by . This book was released on 2009 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of State of the Art Hardware Architectures for Fast Cone Beam CT Reconstruction written by Holger Scherl and published by Springer Science & Business Media. This book was released on 2011-07-29 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Holger Scherl introduces the reader to the reconstruction problem in computed tomography and its major scientific challenges that range from computational efficiency to the fulfillment of Tuy's sufficiency condition. The assessed hardware architectures include multi- and many-core systems, cell broadband engine architecture, graphics processing units, and field programmable gate arrays.
Download or read book Differential Diagnosis in Computed Tomography written by Francis A. Burgener and published by Thieme. This book was released on 2011-11-09 with total page 1748 pages. Available in PDF, EPUB and Kindle. Book excerpt: Differential Diagnosis in Computed Tomography, 2nd edition, is an invaluable reference aid in the evaluation of CT images to help confidently gain a general diagnostic impression and a reasonable differential diagnosis. In contrast to disease-oriented radiology texts, this book is organized by CT findings, enabling the reader to quickly match the appropriate differential diagnosis to CT results. Special features of the second edition: Continuation of the successful Burgener concept: Comprehensive tables describe the imaging patterns of the various diseases that may present on CT, along with other characteristically associated imaging findings and pertinent physiopathologic, pathologic, and clinical data Over 2,000 detailed, high-quality images demonstrating a wide range of common and uncommon CT findings Chapters organized according to anatomic regions, from the brain to the pelvis and the musculoskeletal system, with new chapters on meningeal and calvarian lesions and on trauma Updated and revised sections reflecting the latest advances in CT technology and indications, including accurate staging of intra-articular and spinal fractures and evaluation of vascular diseases Extensive index systematically cross-references diseases and CT findings for optimal access to information Recognizing the central role that CT plays in the field of modern medical imaging, this book is essential for physicians who want to strengthen their diagnostic acumen and CT interpretation skills: radiologists in practice; residents preparing for board exams; and any other physician charged with understanding and interpreting CT images.
Download or read book Characterization and Improvement of a Cone beam CT Scanner for Quantitative Imaging written by Jimish Dilip Joshi and published by . This book was released on 2010 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectral Multi detector Computed Tomography sMDCT written by Xiangyang Tang and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "X-ray computed tomography (CT) has been one of the most popular diagnostic imaging modalities for decades in the clinic for saving patients' life or improving their quality of life. This book is an introductory "one-stop shop" for technological and clinical topics in Computed Tomography (CT). Starting with its fundamentals in physics and mathematics, the book then explores the system architecture and imaging chain, signal detection mechanisms, scan modes and protocols, image reconstruction solutions, and emerging new technologies, such as spectral CT and phase contrast CT. In addition to an in-depth introduction on the major aspects of multi-detector row CT (MDCT) that is being extensively utilized in the clinic for diagnostic imaging, the introduction extends its coverage on cone bean CT (CBCT) dedicated for image-guided oncologic treatment planning, surgery, breast imaging, and cardiovascular/neurological intervention in clinical applications. This book will be an invaluable reference for researchers, engineers, radiological physicians and technologists, and graduate and senior undergraduate students"--
Download or read book Evaluation of Dose and Image Quality Parameters for Cone beam CT Localization Protocols in Radiation Therapy written by Victor Roland Jacome and published by . This book was released on 2009 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development and Evaluation of a Dedicated Breast CT Scanner written by Kai Yang and published by . This book was released on 2007 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A CLINICAL EVALUATION OF CONE BEAM COMPUTED TOMOGRAPHY written by Thomas Patrick Carroll and published by . This book was released on 2015 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Medical Imaging Systems written by Andreas Maier and published by Springer. This book was released on 2018-08-02 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book gives a complete and comprehensive introduction to the fields of medical imaging systems, as designed for a broad range of applications. The authors of the book first explain the foundations of system theory and image processing, before highlighting several modalities in a dedicated chapter. The initial focus is on modalities that are closely related to traditional camera systems such as endoscopy and microscopy. This is followed by more complex image formation processes: magnetic resonance imaging, X-ray projection imaging, computed tomography, X-ray phase-contrast imaging, nuclear imaging, ultrasound, and optical coherence tomography.
