Correction of nonuniform attenuation in cardiac SPECT imaging.
J Nucl Med
; 30(4): 497-507, 1989 Apr.
Article
em En
| MEDLINE
| ID: mdl-2786944
ABSTRACT
Correction for photon attenuation in cardiac SPECT imaging using a measured attenuation distribution with an iterative expectation maximization (EM) algorithm and an iterative Chang algorithm were compared with the conventional filtered backprojection and an iterative EM algorithm without attenuation correction. The attenuation distribution was determined from a transmission computed tomography study that was obtained using an external collimated sheet source. The attenuation of the emitting photons was modeled in the EM algorithm by an attenuated projector-backprojector that used the estimated attenuation distribution to calculate attenuation factors for each pixel along each projection and backprojection ray. Results from a heart-lung phantom study and a 201Tl patient study demonstrated that the iterative EM algorithm with attenuation correction provided improved image quality in terms of reduced streak artifacts and noise, and more accurate quantitative information in terms of improved radioactivity distribution uniformity where uniformity existed, and better anatomic object definition.
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Base de dados:
MEDLINE
Assunto principal:
Algoritmos
/
Tomografia Computadorizada de Emissão
/
Coração
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
J Nucl Med
Ano de publicação:
1989
Tipo de documento:
Article