Application of Gabor filters for detection of dense tissue in mammograms

Determining breast density in mammograms is important both in diagnostic and computer-aided detection applications. Knowing the right breast density and having knowledge of changes in breast density could give a hint of a process which started to happen in a patient. Mammograms are projection images and suffer from problem of overlapping tissue which results in possibility of inaccurate detection of tissue types. The main problem is the fibroglandular tissue which has rather high attenuation of x-rays and is visible as brighter area in the resulting image. Small blood vessels are usually the most common interfering objects in mammograms. In this paper we try to suppress scattered structures which do not represent glandular or dense tissue in order to divide mammograms more accurately in two major tissue types, fatty and dense tissue. For suppressing blood vessels we have used Gabor filters of different size and orientation to detect edges of blood vessels and subtract them from the original image. Obtained results show much more homogenous areas which could be used for easier discrimination between tissue types.