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Concepts for evaluation of image quality in digital radiology

  • Concepts for digital image evaluation are presented for Computed Radiography (CR) and Digital Detector Arrays (DDAs) used for weld inspection. The precise DDA calibration yields an extra ordinary increase of contrast sensitivity up to 10 times in relation to film radiography. Restrictions in spatial resolution caused by pixel size of the DDA are compensated by increased contrast sensitivity. First CR standards were published in 2005 to support the application of phosphor imaging plates in lieu of X-ray film, but they need already a revision based on experiences reported by many users. One of the key concepts is the usage of signal-to-noise (SNR) measurements as equivalent to the optical density of film and film system class. The contrast sensitivity, measured by IQI visibility, depends on three essential parameters: The basic spatial resolution (SRb) of the radiographic image, the achieved signal-to-noise ratio (SNR) and the specific contrast (µeff - effective attenuation coefficient).Concepts for digital image evaluation are presented for Computed Radiography (CR) and Digital Detector Arrays (DDAs) used for weld inspection. The precise DDA calibration yields an extra ordinary increase of contrast sensitivity up to 10 times in relation to film radiography. Restrictions in spatial resolution caused by pixel size of the DDA are compensated by increased contrast sensitivity. First CR standards were published in 2005 to support the application of phosphor imaging plates in lieu of X-ray film, but they need already a revision based on experiences reported by many users. One of the key concepts is the usage of signal-to-noise (SNR) measurements as equivalent to the optical density of film and film system class. The contrast sensitivity, measured by IQI visibility, depends on three essential parameters: The basic spatial resolution (SRb) of the radiographic image, the achieved signal-to-noise ratio (SNR) and the specific contrast (µeff - effective attenuation coefficient). Knowing these 3 parameters for the given exposure condition, inspected material and monitor viewing condition permits the calculation of the just visible IQI element. Furthermore, this enables the optimization of exposure conditions. The new ISO/FDIS 17636-2 describes the practice for digital radiography with CR and DDAs. It considers the first time compensation principles, derived from the three essential parameters. The consequences are described.zeige mehrzeige weniger

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Metadaten
Autoren/innen:Uwe Zscherpel, Uwe Ewert, Mirko Jechow
Persönliche Herausgeber/innen:D. O. Thompson, D. E. Chimenti
Dokumenttyp:Beitrag zu einem Tagungsband
Veröffentlichungsform:Verlagsliteratur
Sprache:Englisch
Titel des übergeordneten Werkes (Englisch):Review of progress in quantitative nondestructive evaluation, volume 31
Jahr der Erstveröffentlichung:2012
Herausgeber (Institution):Iowa State University
Verlag:American Institute of Physics
Verlagsort:Melville, NY
Ausgabe/Heft:1430
Erste Seite:589
Letzte Seite:596
Freie Schlagwörter:Bildqualität; Digitale Detektoren; Filmersatz; Image resolution; Inspection; Production engineering computing; Radiographie; Radiography; Welding; X-ray imaging; ZfP
Veranstaltung:38th Annual Review of Progress in Quantitative Nondestructive Evaluation
Veranstaltungsort:Burlington, VT, USA
Beginndatum der Veranstaltung:2011-07-17
Enddatum der Veranstaltung:2011-07-22
DOI:https://doi.org/10.1063/1.4716281
ISSN:0743-0760
ISSN:0094-243X
ISBN:978-0-7354-1013-8
Bemerkung:
Serientitel: AIP conference proceedings – Series title: AIP conference proceedings
Verfügbarkeit des Dokuments:Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")
Bibliotheksstandort:Sonderstandort: Publica-Schrank
Datum der Freischaltung:19.02.2016
Referierte Publikation:Ja
Datum der Eintragung als referierte Publikation:18.10.2012