Impact of additive noise on system performance of a digital X-ray imaging system.
IEEE Trans Biomed Eng
; 54(1): 69-73, 2007 Jan.
Article
em En
| MEDLINE
| ID: mdl-17260857
ABSTRACT
The impact of additive noise on the performance of a digital X-ray imaging system was investigated. The X-ray system is uniquely designed for small animal studies with a focal spot of 20 microm and an adjustable source-to-object distance for radiography. The noise power spectrum and the detective quantum efficiency of this system were measured. The additive noise increased rapidly when the exposure time exceeded a certain range, since the charge-coupled devices of the detector had no cooling system. The noise power spectrum for the additive noise and the noise of the entire imaging system were studied and compared at different exposure times. The detective quantum efficiency was also measured at different exposure times. It was observed that for exposure times less than 10 s, the detective quantum efficiency ((DQE)(0)) is approximately 0.26, dropping to 0.13 at 4 lp/mm and to 0.026 at 8 lp/mm. However, when the exposure exceeds a certain limit (10 s in this study), the rapidly increased additive noise caused the system to be no longer quantum noise limited, resulting in a decreased detective quantum efficiency and a degraded system performance. For example, at an exposure of 20 s, the DQE(O) is approximately 0.22, dropping to 0.11 at 3 lp/mm and to 0.022 at 8 lp/mm.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Algoritmos
/
Interpretação de Imagem Radiográfica Assistida por Computador
/
Intensificação de Imagem Radiográfica
/
Artefatos
Tipo de estudo:
Diagnostic_studies
Idioma:
En
Revista:
IEEE Trans Biomed Eng
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Estados Unidos