A method for estimating a presence of a pneumothorax abnormality. The method comprises classifying at least one texture feature of each of a plurality of pixels of a chest radiograph (CXR) image to generate an output map, identifying at least one lung contour in said CXR image, identifying a plurality of multiple pixel segments along said at least one lung contour, combining values of pixels in each one of said plurality of multiple pixel segments from said output map to generate a global descriptor for said CXR image, and estimating a presence of said pneumothorax abnormality in said CXR image by applying a statistical classifier on said global descriptor.