Download or read book Statistical Reconstruction Algorithms for Polyenergetic X ray Computed Tomography written by Idris A. Elbakri and published by . This book was released on 2003 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Statistical Image Reconstruction for Quantitative Computed Tomography written by Joshua D. Evans and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Statistical iterative reconstruction (SIR) algorithms for x-ray computed tomography (CT) have the potential to reconstruct images with less noise and systematic error than the conventional filtered backprojection (FBP) algorithm. More accurate reconstruction algorithms are important for reducing imaging dose and for a wide range of quantitative CT applications. The work presented herein investigates some potential advantages of one such statistically motivated algorithm called Alternating Minimization (AM). A simulation study is used to compare the tradeoff between noise and resolution in images reconstructed with the AM and FBP algorithms. The AM algorithm is employed with an edge-preserving penalty function, which is shown to result in images with contrast-dependent resolution. The AM algorithm always reconstructed images with less image noise than the FBP algorithm. Compared to previous studies in the literature, this is the first work to clearly illustrate that the reported noise advantage when using edge-preserving penalty functions can be highly dependent on the contrast of the object used for quantifying resolution. A polyenergetic version of the AM algorithm, which incorporates knowledge of the scanner's x-ray spectrum, is then commissioned from data acquired on a commercially available CT scanner. Homogeneous cylinders are used to assess the absolute accuracy of the polyenergetic AM algorithm and to compare systematic errors to conventional FBP reconstruction. Methods to estimate the x-ray spectrum, model the bowtie filter and measure scattered radiation are outlined which support AM reconstruction to within 0.5% of the expected ground truth. The polyenergetic AM algorithm reconstructs the cylinders with less systematic error than FBP, in terms of better image uniformity and less object-size dependence. Finally, the accuracy of a post-processing dual-energy CT (pDECT) method to non-invasively measure a material's photon cross-section information is investigated. Data is acquired on a commercial scanner for materials of known composition. Since the pDECT method has been shown to be highly sensitive to reconstructed image errors, both FBP and polyenergetic AM reconstruction are employed. Linear attenuation coefficients are estimated with residual errors of around 1% for energies of 30 keV to 1 MeV with errors rising to 3%-6% at lower energies down to 10 keV. In the ideal phantom geometry used here, the main advantage of AM reconstruction is less random cross-section uncertainty due to the improved noise performance.
Download or read book Iterative Reconstruction Algorithms for Polyenergetic X Ray Computerized Tomography written by Nargol Rezvani and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Statistical Modeling and Path based Iterative Reconstruction for X ray Computed Tomography written by Meng Wu and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray computed tomography (CT) and tomosynthesis systems have proven to be indispensable components in medical diagnosis and treatment. My research is to develop advanced image reconstruction and processing algorithms for the CT and tomosynthesis systems. Streak artifacts caused by metal objects such as dental fillings, surgical instruments, and orthopedic hardware may obscure important diagnostic information in X-ray computed tomography (CT) images. To improve the image quality, we proposed to complete the missing kilovoltage (kV) projection data with selectively acquired megavoltage (MV) data that do not suffer from photon starvation. We developed two statistical image reconstruction methods, dual-energy penalized weighted least squares and polychromatic maximum likelihood, for combining kV and selective MV data. Cramer-Rao Lower Bound for Compound Poisson was studied to revise the statistical model and minimize radiation dose. Numerical simulations and phantom studies have shown that the combined kV/MV imaging systems enable a better delineation of structures of interest in CT images for patients with metal objects. The x-ray tube on the CT system produces a wide x-ray spectrum. Polychromatic statistical CT reconstruction is desired for more accurate quantitative measurement of the chemical composition and density of the tissue. Polychromatic statistical reconstruction algorithms usually have very high computational demands due to complicated optimization frameworks and the large number of spectrum bins. We proposed a spectrum information compression method and a new optimization framework to significantly reduce the computational cost in reconstructions. The new algorithm applies to multi-material beam hardening correction, adaptive exposure control, and spectral imaging. Model-based iterative reconstruction (MBIR) techniques have demonstrated many advantages in X-ray CT image reconstruction. The MBIR approach is often modeled as a convex optimization problem including a data fitting function and a penalty function. The tuning parameter value that regulates the strength of the penalty function is critical for achieving good reconstruction results but is difficult to choose. We have developed two path seeking algorithms that are capable of generating a path of MBIR images with different strengths of the penalty function. The errors of the proposed path seeking algorithms are reasonably small throughout the entire reconstruction path. With the efficient path seeking algorithm, we suggested a path-based iterative reconstruction (PBIR) to obtain complete information from the scanned data and reconstruction model. Additionally, we have developed a convolution-based blur-and-add model for digital tomosynthesis systems that can be used in efficient system analysis, task-dependent optimization, and filter design. We also proposed a computationally practical algorithm to simulate and subtract out-of-plane artifacts in tomosynthesis images using patient-specific prior CT volumes.
Download or read book Fundamentals of Computerized Tomography written by Gabor T. Herman and published by Springer Science & Business Media. This book was released on 2009-07-14 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: This revised and updated second edition – now with two new chapters - is the only book to give a comprehensive overview of computer algorithms for image reconstruction. It covers the fundamentals of computerized tomography, including all the computational and mathematical procedures underlying data collection, image reconstruction and image display. Among the new topics covered are: spiral CT, fully 3D positron emission tomography, the linogram mode of backprojection, and state of the art 3D imaging results. It also includes two new chapters on comparative statistical evaluation of the 2D reconstruction algorithms and alternative approaches to image reconstruction.
Download or read book Statistical Signal Processing and Reconstruction Algorithms for Grating based X ray Imaging and Computed Tomography written by Maximilian Teuffenbach and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Statistical Iterative Reconstruction and Dose Reduction in Multi Slice Computed Tomography written by Katharina Hahn and published by . This book was released on 2022-02-14 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computed tomography is one of the most important imaging methods in medical technology. Although computed tomography examinations only make up a small proportion of X-ray examinations, they do make a great contribution to civilizing radiation exposure of the population. By using statistical iterative reconstruction methods, it is possible to reduce the mean radiation dose per examination. While statistical iterative reconstruction methods enable the modeling of physical imaging properties, the user can decide freely and independently about the choice of numerous free parameters. However, every parameterization decision has an influence on the final image quality. In this work, inter alia the definition of the modeling of the forward projection is examined as well as the influence of statistical weights and data redundancies in interaction with various iterative reconstruction techniques. Several extensive studies were put together, which challenge these different combinations in every respect and push the models to their limits. Image quality was assessed using the following quantitative metrics: basic metrics and task-based metrics. The investigation shows that the definition of iterative reconstruction parameters is not always trivial and must always be understood comprehensively to obtain an optimal image quality. Finally, a novel reconstruction algorithm, called FINESSE, is presented, which improves some of the weaknesses of other reconstruction techniques.
Download or read book 3D Image Reconstruction for CT and PET written by Daniele Panetta and published by CRC Press. This book was released on 2020-10-11 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a practical guide to tomographic image reconstruction with projection data, with strong focus on Computed Tomography (CT) and Positron Emission Tomography (PET). Classic methods such as FBP, ART, SIRT, MLEM and OSEM are presented with modern and compact notation, with the main goal of guiding the reader from the comprehension of the mathematical background through a fast-route to real practice and computer implementation of the algorithms. Accompanied by example data sets, real ready-to-run Python toolsets and scripts and an overview the latest research in the field, this guide will be invaluable for graduate students and early-career researchers and scientists in medical physics and biomedical engineering who are beginners in the field of image reconstruction. A top-down guide from theory to practical implementation of PET and CT reconstruction methods, without sacrificing the rigor of mathematical background Accompanied by Python source code snippets, suggested exercises, and supplementary ready-to-run examples for readers to download from the CRC Press website Ideal for those willing to move their first steps on the real practice of image reconstruction, with modern scientific programming language and toolsets Daniele Panetta is a researcher at the Institute of Clinical Physiology of the Italian National Research Council (CNR-IFC) in Pisa. He earned his MSc degree in Physics in 2004 and specialisation diploma in Health Physics in 2008, both at the University of Pisa. From 2005 to 2007, he worked at the Department of Physics "E. Fermi" of the University of Pisa in the field of tomographic image reconstruction for small animal imaging micro-CT instrumentation. His current research at CNR-IFC has as its goal the identification of novel PET/CT imaging biomarkers for cardiovascular and metabolic diseases. In the field micro-CT imaging, his interests cover applications of three-dimensional morphometry of biosamples and scaffolds for regenerative medicine. He acts as reviewer for scientific journals in the field of Medical Imaging: Physics in Medicine and Biology, Medical Physics, Physica Medica, and others. Since 2012, he is adjunct professor in Medical Physics at the University of Pisa. Niccolò Camarlinghi is a researcher at the University of Pisa. He obtained his MSc in Physics in 2007 and his PhD in Applied Physics in 2012. He has been working in the field of Medical Physics since 2008 and his main research fields are medical image analysis and image reconstruction. He is involved in the development of clinical, pre-clinical PET and hadron therapy monitoring scanners. At the time of writing this book he was a lecturer at University of Pisa, teaching courses of life-sciences and medical physics laboratory. He regularly acts as a referee for the following journals: Medical Physics, Physics in Medicine and Biology, Transactions on Medical Imaging, Computers in Biology and Medicine, Physica Medica, EURASIP Journal on Image and Video Processing, Journal of Biomedical and Health Informatics.
Download or read book Medical Imaging and Informatics written by Xiaohong Gao and published by Springer Science & Business Media. This book was released on 2008-07-07 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the thoroughly refeered post-conference proceedings of the Second Interational Conference on Medical Imaging and Informatics, MIMI 2007, held in Beijing, China, in August 2007. The 40 revised full papers presented together with 4 keynote talks were carefully reviewed and selected from 110 submissions. The papers are organized in topical sections on medical image segmentation and registration, medical informatics, PET, fMRI, ultrasound and thermal imaging, 3D reconstruction and visualization. The volume is rounded off by 4 papers from 2 workshops on legal, ethical and social issues in medical imaging and informatics, as well as on computer-aided diagnosis (CAD).
Download or read book Computed Tomography written by Jiang Hsieh and published by SPIE Press. This book was released on 2003 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides an overview of the evolution of CT, the mathematical and physical aspects of the technology, and the fundamentals of image reconstruction using algorithms. Image display is examined from traditional methods through the most recent advancments. Key performance indices, theories behind the measuremet methodologies, and different measurement phantoms in image quality are discussed. The CT scanner is broken down into components to provide the reader with an understanding of their function, their latest advances, and their impact on the CT system. General descriptions and different categories of artifacts, their causes, and their corrections are considered at length.
Download or read book Cone Beam Computed Tomography written by David Sarment and published by John Wiley & Sons. This book was released on 2013-10-18 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written for the clinician, Cone Beam Computed Tomography helps the reader understand how CBCT machines operate, perform advanced diagnosis using CT data, have a working knowledge of CBCT-related treatment planning for specific clinical tasks, and integrate these new technologies in daily practice. This comprehensive text lays the foundation of CBCT technologies, explains how to interpret the data, recognize main pathologies, and utilize CBCT for diagnosis, treatment planning, and execution. Dr. Sarment first addresses technology and principles, radiobiologic risks, and CBCT for head and neck anatomy. The bulk of the text discusses diagnosis of pathologies and uses of CBCT technology in maxillofacial surgical planning, orthodontic and orthognathic planning, implant surgical site preparation, CAD/CAM surgical guidance, surgical navigation, endodontics airway measurements, and periodontal disease.
Download or read book Medical Image Understanding and Analysis written by María Valdés Hernández and published by Springer. This book was released on 2017-06-20 with total page 955 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 21st Annual Conference on Medical Image Understanding and Analysis, MIUA 2017, held in Edinburgh, UK, in July 2017. The 82 revised full papers presented were carefully reviewed and selected from 105 submissions. The papers are organized in topical sections on retinal imaging, ultrasound imaging, cardiovascular imaging, oncology imaging, mammography image analysis, image enhancement and alignment, modeling and segmentation of preclinical, body and histological imaging, feature detection and classification. The chapters 'Model-Based Correction of Segmentation Errors in Digitised Histological Images' and 'Unsupervised Superpixel-Based Segmentation of Histopathological Images with Consensus Clustering' are open access under a CC BY 4.0 license.
Download or read book Reconstruction Algorithms for Dose Reduction in X ray Computed Tomography written by J. E. Gray and published by . This book was released on 1982 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Image Reconstruction from Projections written by Gabor T. Herman and published by . This book was released on 1980 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Image reconstruction from projections. Probability and random variables. An overview of the process of CT. Physical problems associated with data collection in CT. Computer simulation of data collection in CT. Data collection and reconstruction of the head phantom under various assumptions. Basic concepts of reconstruction algorithms. Backprojection. Convolution method for parallel beams. Other transform methods for parallel beams. Convolution methods for divergent beams. The algebraic reconstruction techniques. Quadratic optimization methods. Noniterative series expansion methods. Truly three-dimensional reconstruction. Three-dimensional display of organs. Mathematical background.
Download or read book Fourier Optics and Computational Imaging written by Kedar Khare and published by John Wiley & Sons. This book was released on 2015-09-21 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers both the mathematics of inverse problems and optical systems design, and includes a review of the mathematical methods and Fourier optics. The first part of the book deals with the mathematical tools in detail with minimal assumption about prior knowledge on the part of the reader. The second part of the book discusses concepts in optics, particularly propagation of optical waves and coherence properties of optical fields that form the basis of the computational models used for image recovery. The third part provides a discussion of specific imaging systems that illustrate the power of the hybrid computational imaging model in enhancing imaging performance. A number of exercises are provided for readers to develop further understanding of computational imaging. While the focus of the book is largely on optical imaging systems, the key concepts are discussed in a fairly general manner so as to provide useful background for understanding the mechanisms of a diverse range of imaging modalities.
Download or read book Medical Image Reconstruction written by Gengsheng Lawrence Zeng and published by Walter de Gruyter GmbH & Co KG. This book was released on 2023-07-04 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook introduces the essential concepts of tomography in the field of medical imaging. The medical imaging modalities include x-ray CT (computed tomography), PET (positron emission tomography), SPECT (single photon emission tomography) and MRI. In these modalities, the measurements are not in the image domain and the conversion from the measurements to the images is referred to as the image reconstruction. The work covers various image reconstruction methods, ranging from the classic analytical inversion methods to the optimization-based iterative image reconstruction methods. As machine learning methods have lately exhibited astonishing potentials in various areas including medical imaging the author devotes one chapter to applications of machine learning in image reconstruction. Based on college level in mathematics, physics, and engineering the textbook supports students in understanding the concepts. It is an essential reference for graduate students and engineers with electrical engineering and biomedical background due to its didactical structure and the balanced combination of methodologies and applications,
Download or read book Medical Imaging written by Troy Farncombe and published by CRC Press. This book was released on 2017-12-19 with total page 857 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book has two intentions. First, it assembles the latest research in the field of medical imaging technology in one place. Detailed descriptions of current state-of-the-art medical imaging systems (comprised of x-ray CT, MRI, ultrasound, and nuclear medicine) and data processing techniques are discussed. Information is provided that will give interested engineers and scientists a solid foundation from which to build with additional resources. Secondly, it exposes the reader to myriad applications that medical imaging technology has enabled.
