Comparison of chest computed tomography features between pulmonary tuberculosis patients with culture-positive and culture-negative sputum for non-mycobacteria: A retrospective observational study

Abstract Although complication with non-mycobacterial pneumonia among patients with pulmonary tuberculosis (TB) may lead to poor prognosis, discrimination between TB complicated with and without non-mycobacterial pneumonia using radiological imaging has not been fully elucidated. We aimed to clarify the differences in chest computed tomography (CT) features between pulmonary TB patients with culture-positive and culture-negative sputum for non-mycobacteria.We retrospectively included consecutive patients admitted to our hospital from January 2013 to December 2015 for bacteriologically-confirmed pulmonary TB, who were tested by sputum culture for non-mycobacteria, and who underwent chest CT within 2 weeks before or after admission. Chest CT features were compared between pulmonary TB patients who had positive non-mycobacterial cultures and in those who had not.Of 202 patients with pulmonary TB, 186 (92%) were tested by sputum culture for non-mycobacteria and underwent chest CT. Among these, non-mycobacteria were isolated in 118 patients (63%), while 68 patients (37%) had negative cultures. Patients with a positive culture for non-mycobacteria were significantly older and had lower levels of physical activity and albumin, higher levels of C-reactive protein, and a greater number of respiratory failures. By CT, emphysematous lesions, ground-glass opacities, airspace consolidation, air-bronchogram, interlobular septal thickening, bronchiectasis, pleural effusion, pleural thickening, and lymph node enlargement were more frequently in patients with a positive culture for non-mycobacteria. These chest CT features could be helpful for detecting complication with non-mycobacterial pneumonia in patients with pulmonary TB.