Document Detail


Characterisation of fan-beam collimators.
MedLine Citation:
PMID:  11303883     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Fan-beam collimators offer a good balance between resolution and noise. The collimator response may be included in iterative reconstruction algorithms in order to improve single-photon emission tomography (SPET) resolution. To this end, accurate determination of the focal region and characterisation of the collimator response as a function of the source co-ordinates must be performed. In this paper, a method to characterise fanbeam collimators is evaluated. First, we calculated the real focal region and the accuracy of the collimator convergence. Then, we confirmed the hypothesis that Gaussian distributions adequately fit the collimator responses, although no individualised treatment was performed for the tails of detector response which are associated with scattering and septal penetration. Finally, analytical functions were used to model the resolution and sensitivity. The parameter values in these functions were obtained from experimental measures by non-linear regression fitting. Our findings show differences of 1.43% between nominal and real focal length and standard deviations of 2.5 mm in the x-direction and 7.1 mm in the y-direction for the focal convergence. The correlation coefficients between experimental and predicted values were 0.994 for resolution and 0.991 for sensitivity. As a consequence, the proposed method can be used to characterise the collimator response.
Authors:
D Pareto; J Pavía; C Falcón; I Juvells; A Cot; D Ros
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Publication Detail:
Type:  Evaluation Studies; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  European journal of nuclear medicine     Volume:  28     ISSN:  0340-6997     ISO Abbreviation:  Eur J Nucl Med     Publication Date:  2001 Feb 
Date Detail:
Created Date:  2001-04-16     Completed Date:  2001-08-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7606882     Medline TA:  Eur J Nucl Med     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  144-9     Citation Subset:  IM    
Affiliation:
Laboratori de Biofísica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona, Spain.
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MeSH Terms
Descriptor/Qualifier:
Algorithms
Nonlinear Dynamics
Quality Control
Regression Analysis
Tomography, Emission-Computed, Single-Photon / instrumentation*,  standards,  statistics & numerical data

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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