Image quality of a digital chest radiography system based on a selenium detector.
Med Phys
; 21(4): 509-16, 1994 Apr.
Article
em En
| MEDLINE
| ID: mdl-8058016
ABSTRACT
A digital chest radiography system has been developed, with a detector based on the photoelectric properties of amorphous selenium. The selenium layer is deposited on a cylindrical aluminium drum, large enough to cover the full field of view for chest imaging. The electrostatic charge image which is formed on the selenium surface after x-ray exposure is read out by electrometer probes using fast drum rotation. For a physical evaluation of the attainable image quality, the characteristic curve, the modulation transfer function, and the noise spectra were measured. From these measurements, the signal-to-noise properties of the detector in terms of detective quantum efficiency (DQE) and noise equivalent quanta (NEQ) were derived. The results show that the selenium-based detector has a wide dynamic range and a significantly better DQE than screen-film and storage phosphor systems for spatial frequencies below the Nyquist limit (2.7 lp/mm). As a consequence, the detectability of small, low-contrast details is considerably improved.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Radiografia Torácica
/
Intensificação de Imagem Radiográfica
Tipo de estudo:
Diagnostic_studies
/
Evaluation_studies
Limite:
Humans
Idioma:
En
Revista:
Med Phys
Ano de publicação:
1994
Tipo de documento:
Article