In developing countries, pulmonary tuberculosis is still a common disease particularly among the socioeconomically disadvantaged, elderly and chronically debilitated individuals Chest radiography is the imaging modality of choice in the initial evaluation of patients with suspected pulmonary tuberculosis. HRCT is more sensitive than chest radiography in the detection and characterization of subtle disease in patients with suspected mycobacterial infection. Aim of my study was to assess the HRCT findings of active pulmonary tuberculosis and to find out the association between HRCT findings in active pulmonary tuberculosis with sputum positivity.

Materials and Methods- This is a Prospective Observational study conducted in Radio Diagnosis Department Govt. Medical College, Thrissur from January 2014- June 2015 (18 months). The study sample comprised of 100 patients clinically, radiologically or bacteriologically diagnosed as pulmonary tuberculosis. The findings we took to interpret active pulmonary tuberculosis include centrilobular nodule, “tree in bud” appearance, consolidation, cavity, ground glassing, lymphadenopathy, pleural effusion;  parenchymal calcifications, bronchiectasis, miliary nodules and emphysema.

Observation and Conclusion- HRCT findings like centrilobular nodules, “tree in bud”, cavitation and mediastinal lymphadenopathy are the best parameters of active pulmonary tuberculosis and there is statistically significant association between these findings and sputum positivity.

Keywords - High Resolution Computed Tomography, pulmonary tuberculosis, Centrilobular Nodules, Tree In Bud appearance.