Detection of Calcifications in Digitized Mammograms Using Modification of Wavelet Packet Transform Coefficients


IEICE TRANSACTIONS on Information and Systems   Vol.E85-D   No.1   pp.96-107
Publication Date: 2002/01/01
Online ISSN: 
Print ISSN: 0916-8532
Type of Manuscript: Special Section PAPER (Special Issue on Measurements and Visualization Technology of Biological Information)
Category: Image Processing
breast cancer,  mammograms,  detection of calcifications,  computer assisted diagnosis,  image processing,  

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This paper presents a method for detection of calcification, which is an important early sign of breast cancer in mammograms. Since information of calcifications is located in inhomogeneous background and noises, it is hard to be detected. This method uses wavelet packet transform (WPT) for elimination of the background image related to low frequency components. However, very high frequency signals of noises exist with the calcifications and make it hard to suppress them. Since calcification location can be represented as vertical, horizontal, and diagonal edges in time-frequency domain, the edges in spatial domain can be utilized as a filter for noise suppression. Then the image from inverse transform will contain only required information. A free-response operating characteristic (FROC) curve is used to evaluate a performance of proposed method by applying it to thirty images of calcifications. The results show 82.19 percent true positive detection rate at the cost of 6.73 false positive per image.