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Assessment of radiographic screen-film systems: a comparison between the use of a microdensitometer and a drum film digitiser

Verdun, F. R. ; Pachoud, M. ; Bergmann, D. ; Buhr, E.

In: Radiation Protection Dosimetry, 2005, vol. 114, no. 1-3, p. 208-213

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    Titre
    • Assessment of radiographic screen-film systems: a comparison between the use of a microdensitometer and a drum film digitiser
    Auteur
    • Verdun, F. R.. University Institute for Applied Radiophysics, Grand-Pré 1, CH-Lausanne, Switzerland
    • Pachoud, M.. University Institute for Applied Radiophysics, Grand-Pré 1, CH-Lausanne, Switzerland
    • Bergmann, D.. Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, D-38116 Braunschweig, Germany
    • Buhr, E.. Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, D-38116 Braunschweig, Germany
    Type de document
    • Postprint
    Langue
    • Anglais
    Publié dans
    • Radiation Protection Dosimetry, 2005, vol. 114, no. 1-3, p. 208-213. Oxford University Press
    Autre version électronique
    Classification
    • Santé
    Identifiant OAI-PMH
    • oai:doc.rero.ch:292800
    Summary
    A high-end drum film digitiser (Tango, Germany) and a calibrated linear microdensitometer developed by PTB were used to assess the modulation transfer function (MTF) and the noise power spectra (NPS) of 3 mammographic screen film systems at optical density levels of 0.8, 1.5 and 2.5. The use of a drum scanner to assess MTF and NPS data appears to be adequate but requires an appropriate characterisation of the scanner to verify its internal noise level and its MTF. It is further necessary to calibrate the scanner output in terms of visual diffuse optical densities. Processing of two-dimensional digital data of grating images need to be more strictly defined for accurate MTF measurements of screen-film systems. Nevertheless, even now it seems to be feasible to use commercially available high-end and well calibrated scanners to assess screen film systems. This is especially important for quality assurance purposes because important parameters of screen film systems such like MTF and NPS can now be determined without using sophisticated microdensitometers which are not commercially available