Abstract:
Breast cancer is one of the leading cancers in the female population and
most of them are lethal; to save lives breast cancer should be identified in
its early stage. In Sri Lanka 25% of the detected cancers are recognized as
breast cancers in each successive year between 2000 to 2005.
Mammography is the most successful method to diagnose breast cancers.
Mostly mammograms are poor quality images, and doesn‘t provide any
hard evidence to diagnose cancers although it has the accuracy of 80% -
90%. And this is where the mammogram enhancement is essentially
needed. Among various image enhancement techniques, histogram
equalization is the most convenient method to enhance images. But
unfortunately many prevailing histogram equalization techniques are not
suitable for mammogram enhancement, because they can‘t accurately
separate noise from the image. Detecting cancers in a Mammogram is
rather delicate process which needs fairly controlled image enhancement
with noise reduction. The proposed histogram equalization technique can
control the amount of enhancement and it intelligently separates the noise
from the interested regions and enhances the suspicious areas.
Many histogram equalization methods are available to enhance images.
But the common problem with all these algorithms is they did not concern
about the actual intensities of the pixels at all. In fact, this leads the whole
image enhancement into failures by over enhancing the images. However,
lack of controllability is the major obstacle to use histogram equalization
in mammogram enhancement. Actual intensities of the pixels must be
contributed to the process of enhancement to control the amount of
enhancement and prevent destroying the valuable information. The
proposed algorithm uses a set of candidate intensities to pick the most
appropriate intensity for the enhancement just like a genetic algorithm.
Newly taken mammograms were used to experiment the power of
enhancement of the algorithm. The image samples were taken from the
Karapitiya hospital, Galle, Sri Lanka, with the authorization from the
Director there. The major concerns were how well the algorithm can reduce the noise and highlight the cancerous areas of the images.
Obviously this enhancement must assist the observers to find hard
evidence to detect cancers. Following shows a mammogram image before
and after the enhancement.Identifying a breast cancer is a tough job and it needs years of practice
and some sophisticated technology. But still 10% of breast cancers are
missed by radiologists. This happens mainly due to noise of the images
and complex overlying and underlying structures in the cancer images.
Almost every Mammogram is a poor quality image which doesn‘t provide
enough hard evidence to pursue and diagnose cancers. This research led
to produce an image enhancing algorithm which can be used to enhance
mammograms to detect early stage breast cancers to support and assist in
medical treatments.
