| Nonlinear polychromatic and noise artifacts in x-ray computed tomography images. | |
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MedLine Citation:
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PMID: 457966 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The variance of the image noise in computed X-ray transmission tomography (CT) due to quantum noise is in a first approximation a nonlinear function of X-ray attenuation. Beam hardening in CT is also a nonlinear function of attenuation. We present a theoretical study of both phenomena. Computer simulations and numerical results show that both nonlinear dependencies have quite similar effects on image quality. We also show how the two-dimensional distribution of the noise variance in a CT image is a weighted superposition of images obtained by backprojecting integer powers of the noiseless projection data corresponding to the scanned object. The streak-like pattern in the image noise due to the anisotropic nature of the noise cross-correlation function is discussed. We also discuss how these nonlinear phenomena affect noise filtering and tissue characterization using statistical parameters. |
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Authors:
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A J Duerinckx; A Macovski |
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Publication Detail:
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Type: Comparative Study; Journal Article |
Journal Detail:
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Title: Journal of computer assisted tomography Volume: 3 ISSN: 0363-8715 ISO Abbreviation: J Comput Assist Tomogr Publication Date: 1979 Aug |
Date Detail:
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Created Date: 1979-09-25 Completed Date: 1979-09-25 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 7703942 Medline TA: J Comput Assist Tomogr Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 519-26 Citation Subset: IM |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Electronics, Medical Humans Mathematics Models, Theoretical Radiographic Image Enhancement* Technology, Medical Tomography, X-Ray Computed / methods* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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