BJR
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Costaridou, L
Right arrow Articles by Panayiotakis, G
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Costaridou, L
Right arrow Articles by Panayiotakis, G
British Journal of Radiology 74 (2001),913-919 © 2001 The British Institute of Radiology

Full paper

Quantifying image quality at breast periphery vs mammary gland in mammography using wavelet analysis

L Costaridou, PhD P Sakellaropoulos, MSc A P Stefanoyiannis, MSc E Ungureanu, MSc and G Panayiotakis, PhD

Department of Medical Physics, School of Medicine, University of Patras, 26500 Patras, Greece

Correspondence: George Panayiotakis

Use of high contrast film–screen systems in mammography, in combination with the fact that exposure parameters are selected to ensure good visualization of the mammary gland, results in overexposure of the film area corresponding to the breast periphery, therefore decreasing image quality. The aim of this work was to provide a quantitative evaluation of image quality at the breast periphery compared with the mammary gland. To deal with the difficulties in quantification of image quality introduced by low contrast encountered at the breast periphery, wavelet analysis has been used for derivation of a contrast indicator (CI) and a noise indicator (NI), taking into account local grey level variations. Gradient magnitude coefficients corresponding to region of interest (ROI) grey level values are the basis of CI definition. Mammary gland and breast periphery were sampled by equally spaced ROIs, the quantity of which was determined by a heuristic method. For NI definition, the power values of gradient magnitude coefficients corresponding to the ROI were utilized. Image quality at the breast periphery compared with the mammary gland was evaluated using 150 craniocaudal images from the Digital Database for Screening Mammography. Measurements were carried out using a tool developed in our department. A 50% contrast decrease at the breast periphery was observed, while noise decreased by approximately 2%.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
BJR DMFR IMAGING  ALL BIR JOURNALS 
Copyright © 2001 by the British Institute of Radiology.