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Title: The use of wavelet filters for reducing noise in posterior fossa Computed Tomography images

Wavelet transform based de-noising like wavelet shrinkage, gives the good results in CT. This procedure affects very little the spatial resolution. Some applications are reconstruction methods, while others are a posteriori de-noising methods. De-noising after reconstruction is very difficult because the noise is non-stationary and has unknown distribution. Therefore, methods which work on the sinogram-space don’t have this problem, because they always work over a known noise distribution at this point. On the other hand, the posterior fossa in a head CT is a very complex region for physicians, because it is commonly affected by artifacts and noise which are not eliminated during the reconstruction procedure. This can leads to some false positive evaluations. The purpose of our present work is to compare different wavelet shrinkage de-noising filters to reduce noise, particularly in images of the posterior fossa within CT scans in the sinogram-space. This work describes an experimental search for the best wavelets, to reduce Poisson noise in Computed Tomography (CT) scans. Results showed that de-noising with wavelet filters improved the quality of posterior fossa region in terms of an increased CNR, without noticeable structural distortions.
Authors:
 [1] ; ; ;  [2]
  1. Centro de Ingeniería Clínica. Guacalote y Circunvalación, Santa Clara 50200 (Cuba)
  2. Centro de Estudios de Electrónica y Tecnologías de la Información (CEETI), Universidad Central Marta Abreu de las Villas, Carretera a Camajuaní, km. 5 1/2 Santa Clara 54830 (Cuba)
Publication Date:
OSTI Identifier:
22390514
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1626; Journal Issue: 1; Conference: 13. Mexican Symposium on Medical Physics, Leon, Guanajuato (Mexico), 15-16 Mar 2014; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CAT SCANNING; COMPARATIVE EVALUATIONS; FILTERS; IMAGE PROCESSING; IMAGES; NOISE; SHRINKAGE; SPACE; SPATIAL RESOLUTION