Breast peripheral area correction in digital mammograms.
Digital mammograms may present an overexposed area in the peripheral part of the breast, which is visually shown as a darker area with lower contrast. This has a direct impact on image quality and affects image visualisation and assessment. This paper presents an automatic method to enhance the overexposed peripheral breast area providing a more homogeneous and improved view of the whole mammogram. The method automatically restores the overexposed area by equalising the image using information from the intensity of non-overexposed neighbour pixels. The correction is based on a multiplicative model and on the computation of the distance map from the breast boundary. A total of 334 digital mammograms were used for evaluation. Mammograms before and after enhancement were evaluated by an expert using visual comparison. In 90.42% of the cases, the enhancement obtained improved visualisation compared to the original image in terms of contrast and detail. Moreover, results show that lesions found in the peripheral area after enhancement presented a more homogeneous intensity distribution. Hence, peripheral enhancement is shown to improve visualisation and will play a role in further development of CAD systems in mammography.
Department of Computer Architecture and Technology, University of Girona, Girona, Spain. Electronic address: txell@eia.udg.edu.
Meritxell
M
Tortajada
Department of Computer Architecture and Technology, University of Girona, Girona, Spain.
Arnau
A
Oliver
Department of Computer Architecture and Technology, University of Girona, Girona, Spain.
Robert
R
Martí
UDIAT-Centre Diagnòstic, Corporació Parc Taulí, 08208 Sabadell, Spain.
Sergi
S
Ganau
UDIAT-Centre Diagnòstic, Corporació Parc Taulí, 08208 Sabadell, Spain.
Lidia
L
Tortajada
UDIAT-Centre Diagnòstic, Corporació Parc Taulí, 08208 Sabadell, Spain.
Melcior
M
Sentís
Department of Computer Architecture and Technology, University of Girona, Girona, Spain.
Jordi
J
Freixenet
Department of Computer Science, Aberystwyth University, Aberystwyth SY23 3DB, UK.
Reyer
R
Zwiggelaar
D000465:Algorithms; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D018482:Muscle, Skeletal / Q000473:pathology; D010363:Pattern Recognition, Automated; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012984:Software
Computer-assisted diagnosis; Image processing; Image quality; Mammography; Radiographic image enhancement