Computer-Aided Detection of Acinar Shadows in Chest Radiographs

Despite the technological advances in medical diagnosis, accurate detection of infectious tuberculosis (TB) still poses challenges due to complex image features and thus infectious TB continues to be a public health problem of global proportions. Currently, the detection of TB is mainly conducted visually by radiologists examining chest radiographs (CXRs). To reduce the backlog of CXR examination and provide more precise quantitative assessment, computer-aided detection (CAD) systems for potential lung lesions have been increasingly adopted and commercialized for clinical practice. CADs work as supporting tools to alert radiologists on suspected features that could have easily been neglected. In this paper, an effective CAD system aimed for acinar shadow regions detection in CXRs is proposed. This system exploits textural and photometric features analysis techniques which include local binary pattern (LBP), grey level co-occurrence matrix (GLCM) and histogram of oriented gradients (HOG) to analyze target regions in CXRs. Classification of acinar shadows using Adaboost is then deployed to verify the performance of a combination of these techniques. Comparative study in different image databases shows that the proposed CAD system delivers consistent high accuracy in detecting acinar shadows.