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Algebraic Reconstruction Technique
frame, Animated sequence of reconstruction steps, one iteration. The algebraic reconstruction technique (ART) is an iterative reconstruction technique used in computed tomography. It reconstructs an image from a series of angular projections (a sinogram). Gordon, Bender and Herman first showed its use in image reconstruction; whereas the method is known as Kaczmarz method in numerical linear algebra. An advantage of ART over other reconstruction methods (such as filtered backprojection) is that it is relatively easy to incorporate prior knowledge into the reconstruction process. ART can be considered as an iterative solver of a system of linear equations A x = b , where: : A is a sparse m \times n matrix whose values represent the relative contribution of each output pixel to different points in the sinogram ( m being the number of individual values in the sinogram, and n being the number of output pixels); : x represents the pixels in the generated (output) imag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algebraic Reconstruction Technique - Animated
Algebraic may refer to any subject related to algebra in mathematics and related branches like algebraic number theory and algebraic topology. The word algebra itself has several meanings. Algebraic may also refer to: * Algebraic data type, a datatype in computer programming each of whose values is data from other datatypes wrapped in one of the constructors of the datatype * Algebraic numbers, a complex number that is a root of a non-zero polynomial in one variable with integer coefficients * Algebraic functions, functions satisfying certain polynomials * Algebraic element, an element of a field extension which is a root of some polynomial over the base field * Algebraic extension, a field extension such that every element is an algebraic element over the base field * Algebraic definition, a definition in mathematical logic which is given using only equalities between terms * Algebraic structure, a set with one or more finitary operations defined on it * Algebraic, the order of ent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iterative Reconstruction
Iterative reconstruction refers to Iteration, iterative algorithms used to reconstruct 2D and 3D reconstruction, 3D images in certain Digital imaging, imaging techniques. For example, in computed tomography an image must be reconstructed from projections of an object. Here, iterative reconstruction techniques are usually a better, but computationally more expensive alternative to the common filtered back projection (FBP) method, which directly calculates the image in a single reconstruction step.Herman, G. T.Fundamentals of computerized tomography: Image reconstruction from projection 2nd edition, Springer, 2009 In recent research works, scientists have shown that extremely fast computations and massive parallelism is possible for iterative reconstruction, which makes iterative reconstruction practical for commercialization. Basic concepts The reconstruction of an image from the acquired data is an inverse problem. Often, it is not possible to exactly solve the inverse problem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computed Tomography
A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or radiology technologists. CT scanners use a rotating X-ray tube and a row of detectors placed in a gantry to measure X-ray attenuations by different tissues inside the body. The multiple X-ray measurements taken from different angles are then processed on a computer using tomographic reconstruction algorithms to produce tomographic (cross-sectional) images (virtual "slices") of a body. CT scans can be used in patients with metallic implants or pacemakers, for whom magnetic resonance imaging (MRI) is contraindicated. Since its development in the 1970s, CT scanning has proven to be a versatile imaging technique. While CT is most prominently used in medical diagnosis, it can also be used to form images of non-living objects. The 1979 N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Gordon (theoretical Biologist)
Richard "Dick" Gordon (born November 6, 1943) is an American theoretical biologist. He was born in Brooklyn, New York, the eldest son of Jack Gordon, a salesman and American handball champion, and artist Diana Gordon. He is married to retired scientist Natalie K Björklund with whom he co-wrote his second book and several academic publications. He has three sons, Leland, Bryson and Chason Gordon and three stepchildren Justin, Alan and Lana Hunstad. Gordon was a professor at the University of Manitoba in Winnipeg, Manitoba from 1978 to 2011. He is retired and currently volunteers as a scientist for the Gulf Specimen Marine Laboratory in Panacea, Florida where he winters, and he holds an adjunct position in the Department of Obstetrics & Gynecology, Wayne State University. Gordon lives in Alonsa, Manitoba, Canada. Academic career Gordon was educated at University of Chicago where he did an undergraduate degree in mathematics and a PhD at University of Oregon in chemical physics u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gabor Herman
Gabor Tamas Herman is a Hungarian-American professor of computer science. He is Emiritas Professor of Computer Science at The Graduate Center, City University of New York (CUNY) where he was Distinguished Professor until 2017. He is known for his work on computerized tomography. He is a fellow of the Institute of Electrical and Electronics Engineers (IEEE). Early life and education Herman studied mathematics at the University of London, receiving his B.Sc. in 1963 and M.Sc. in 1964. In 1966, he received his M.S. in electrical engineering from the University of California, Berkeley, and in 1968 his Ph.D. in mathematics from the University of London. Career In 1969, Herman joined the department of computer science at State University of New York at Buffalo as an assistant professor. He became an associate professor in 1970 and a full professor in 1974. In 1976, he formed the Medical Image Processing Group. In 1980, he published the first edition of ''Reconstruction from Projections' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Theoretical Biology
The ''Journal of Theoretical Biology'' is a biweekly peer-reviewed scientific journal covering theoretical biology, as well as mathematical, computational, and statistical aspects of biology. Some research areas covered by the journal include cell biology, evolutionary biology, population genetics, morphogenesis, and immunology. The journal was established in 1961. Its founding editor-in-chief was English biologist James F. Danielli, who remained editor until his death in 1984. The journal is published by Elsevier and, , the editors-in-chief are Denise Kirschner ( University of Michigan Medical School), Mark Chaplain ( University of St. Andrews), and Akira Sasaki (The university for advanced studies, SOKENDAI, Hayama). Lewis Wolpert served as editor-in-chief for more than 55 years. According to the ''Journal Citation Reports'' the journal has a 2020 impact factor of 2.691. Notable articles The following are the most highly cited articles (more than 2,000 citations at April ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaczmarz Method
The Kaczmarz method or Kaczmarz's algorithm is an iterative algorithm for solving linear equation systems A x = b . It was first discovered by the Polish mathematician Stefan Kaczmarz, and was rediscovered in the field of image reconstruction from projections by Richard Gordon, Robert Bender, and Gabor Herman in 1970, where it is called the Algebraic Reconstruction Technique (ART). ART includes the positivity constraint, making it nonlinear. The Kaczmarz method is applicable to any linear system of equations, but its computational advantage relative to other methods depends on the system being sparse. It has been demonstrated to be superior, in some biomedical imaging applications, to other methods such as the filtered backprojection method. It has many applications ranging from computed tomography (CT) to signal processing. It can be obtained also by applying to the hyperplanes, described by the linear system, the method of successive projections onto convex sets (POCS). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal-to-noise Ratio (imaging)
Signal-to-noise ratio (SNR) is used in imaging to characterize image quality. The sensitivity of a (digital or film) imaging system is typically described in the terms of the signal level that yields a threshold level of SNR. Industry standards define sensitivity in terms of the ISO film speed equivalent, using SNR thresholds (at average scene luminance) of 40:1 for "excellent" image quality and 10:1 for "acceptable" image quality. SNR is sometimes quantified in decibels (dB) of signal power relative to noise power, though in the imaging field the concept of "power" is sometimes taken to be the power of a voltage signal proportional to optical power; so a 20 dB SNR may mean either 10:1 or 100:1 optical power, depending on which definition is in use. Definition of SNR Traditionally, SNR is defined to be the ratio of the average signal value \mu_\mathrm to the standard deviation of the signal \sigma_\mathrm: : \mathrm = \frac when the signal is an optical intensity, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Imaging
Medical imaging is the technique and process of imaging the interior of a body for clinical analysis and medical intervention, as well as visual representation of the function of some organs or tissues (physiology). Medical imaging seeks to reveal internal structures hidden by the skin and bones, as well as to diagnose and treat disease. Medical imaging also establishes a database of normal anatomy and physiology to make it possible to identify abnormalities. Although imaging of removed organ (anatomy), organs and Tissue (biology), tissues can be performed for medical reasons, such procedures are usually considered part of pathology instead of medical imaging. Measurement and recording techniques that are not primarily designed to produce images, such as electroencephalography (EEG), magnetoencephalography (MEG), electrocardiography (ECG), and others, represent other technologies that produce data susceptible to representation as a parameter graph versus time or maps that contain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
