Holistic Contrast enhancement of Carpals Ossification sites for Skeletal Age Assessment System

Abstract

Pediatricians often apply bone age assessment to measure the skeletal maturity of children and to predict the future height. These discrepancies are good indicators for diagnosing growth disorders. Normally, left hand skeletal is employed in this assessment. The low quality of ossification sites of carpals deteriorates the pediatrician's visibility in inspecting the pertinent radiographic manifestations. This in turn affects the bone age assessment. Therefore, we have to enhance the quality before assessing them. Histogram equalization is one of the contrast enhancement techniques that suit this enhancement. Existing histogram equalizations, however, are confronting with problems in preserving the brightness and details as well as preventing the contrast from being over-enhanced or under-enhanced simultaneously. We propose the comprehensive histogram equalization considering all criteria of desired histogram-equalized image to produce moderately contrast enhanced carpals' ossification sites. Qualitative results show that the determining features of maturity stages have been emphasized in some of the Pareto optimized image. The improvement for Pareto optimized bi-histogram equalization is significant for all stages: 7.16%, 12.4%, 16.03%, 21.21% and 18.51%. We conclude that the Pareto optimized images able to improve the classifier accuracy that estimate the maturity stage of the carpal bones.