A Method for Enhancing Dot-like Regions in Chest X-rays Based on Directional Scale LoG Filter ?

Chest radiography for detection of lung nodules can benefit from enhancement of suspicious structures in the lung-in many cases, these are regions containing a spherical structure and appear as a dot. In order to visualize such areas in chest radiography more clearly, and to better determine the extent of that region, in this paper, an improved Laplacian of Gaussian (LoG) filter based method for enhancing dot-like regions in chest X-rays is proposed. By permitting different scale values in the X and Y direction, the proposed method allows specific directional textures in lung nodules to be enhanced. To compensate for the visual vague problem caused by Gaussian operation, a visual correction factor is also introduced. Experiments show that the technique proposed in this paper can effectively enhance the contrast between lung nodules and its surrounding tissue, and make lung nodule easier be detected by human visual perception.