Diagnosis of the Sputum Smear Positive and Sputum Smear Negative Pulmonary Tuberculosis - The Role of High - Resolution Computed Tomography of Chest

Abstract

BACKGROUND
 Mycobacterium tuberculosis complex causes pulmonary tuberculosis (PT) which is a major public health problem worldwide and endemic in India. PT diagnosis is done by high-resolution computed tomography (HRCT) which has high sensitivity and specificity.
 METHODS
 At a tertiary hospital, this cross-sectional study was conducted for 3 years. Patients presenting with productive cough with or without haemoptysis, shortness of breath, fever with night sweats or weight loss were suspected of having tuberculosis and underwent HRCT. PT was defined as the presence of consolidation, centrilobular nodules, and branching nodules with a tree in bud appearance with or without lymphadenopathy and pleural effusion on HRCT.
 RESULTS
 In this study, a total of 118 patients with a mean age of 51.85 ± 16.86 years were included. 64 (54.2%) were males and 54 (45.76%) were females out of 118 patients. Sputum smear was negative in a total of 66 (55.9%) patients and positive in 52(44.06%) patients. 84.26% was the diagnostic accuracy of HRCT in diagnosing PT with sensitivity, specificity, PPV and NPV of 84.28%, 83.33%, 78.98%, and 99.02%, respectively. HRCT had diagnostic accuracy, sensitivity, specificity, PPV and NPV of 86.40%, 89.46%, 83.42%, 94.14% and 72.43%, respectively in sputum smear positive patients. Whereas it was 83.87%, 91.54%, 75.40%, 64.57%, and 92.14%, respectively in sputum smear negative patients.
 CONCLUSIONS
 In diagnosing sputum smear-positive and sputum smear-negative PT, HRCT has high sensitivity. The specificity of HRCT was high in diagnosing sputum smear-positive PT, whereas in case of sputum smear-negative PT it was slightly low.