Detecting Tuberculosis in Chest Radiographs Using SVM Classifier

Abstract
Tuberculosis (TB)and HIV/AIDS are the main causes of mortality in adults aged 15-49 years in Sub Saharan Africa (SSA). The interaction between tuberculosis and HIV/AIDS makes the diagnosis and management of the confection difficult. A cross sectional hospital based study was conducted at Haydom Lutheran Hospital (HLH) to assess the interaction between tuberculosis, HIV/AIDS and coinfection in relation to the CD4 T cells. Furthermore, CD4 T cell counts in healthy subjects in different age groups were determined for the purpose of establishing reference values. Physical examination and investigation including sputum for fluorescence microscopy and culture, tuberculosis drugs susceptibility testing and Chest X-Ray (CXR) were done for all tuberculosis and HIV/AIDS patients. Sputum samples were stained using aura mine and examined by fluorescence microscopy. Sputum culture was done using Lowenstein Jensen media and sensitivity to the first line TB drugs was tested. The proposed computer-aided diagnostic system for TB screening, which is ready for field deployment, achieves a performance that approaches the performance of human experts achieve an area under the ROC curve (AUC) of 87% (78.3%accuracy) for the first set, and an AUC of 90% (84% accuracy)for the second set. For the first set, compare the system performance with the performance of radiologists. When trying not to miss any positive cases, radiologists achieve an accuracy of about 82% on this set, and their false positive rate is about half of system’s rate.
Index Terms— Chest radiographs, computer-aided diagnosis, lung pattern recognition and classification, segmentation, tuberculosis (TB), X-ray imaging.
I.Introduction
TUBERCULOSIS (TB) is the second leading cause of death from an infectious disease worldwide, after HIV, with a mortality rate of over 1.2 million people in 2010 [1].With about onethird of the world’s population having latent TB, and an estimated nine million new cases occurring every year, TB is a major global health problem [2]. TB is an infectious disease caused by the bacillus Mycobacterium tuber culosis, which typically affects the lungs. It spreads through the air when people with active TB cough, sneeze, or otherwise expel infectious bacteria. Moreover, opportunistic infections in immunocompromised HIV/AIDS patients have exacerbated the problem. The increasing appearance of multi-drug resistant TB has further created an urgent need for acost effective screening technology to monitor progress duringtreatment.Several antibiotics exist for treating TB. While mortalityrates are high when left untreated, treatment with antibioticsgreatly improves the chances of survival. In clinical trials, curerates over 90% have been documented. Unfortunately, diagnosing TB is still a major challenge.The definitive test for TBis the identification of Mycobacterium tuberculosis in a clinicalsputum or pus sample, which is the current gold standard. However, it may take several months to identify thisslow-growing organism in the laboratory. Another techniqueis sputum smear microscopy, in which bacteria in sputumsamples are observed under a microscope.
This technique was developed more than 100 years ago. In addition, several skin tests based on immune response are available for determining whether an individual has contracted TB. However, skin testsare not always reliable. The latest development for detectionare molecular diagnostic tests that are fast and accurate, and that are highly sensitive and specific. However, further financialsupport is required for these tests to become common place. Thus the rest of the paper organized in such a way that the Section 2 describes Methods, Section 3 shows proposed system, section 4 ends with conclusion.