Diagnostic utility of chest computerized tomography in the diagnosis of recurrence among sputum scarce and sputum negative previously treated pulmonary tuberculosis suspects

Abstract

Objective: The objective was to study the sensitivity, specificity, and diagnostic accuracy of various computed tomography (CT) chest findings in diagnosing recurrence among pulmonary tuberculosis (PTB) suspects. Materials and Methods: A prospective observational study was conducted in a tertiary care hospital in New Delhi. A total of 130 suspects with a past history of treatment for PTB, who presented with any of the symptoms suggestive of recurrence were included. Sputum-positive, HIV-positive patients, pregnant females, and patients aged 90%). Hemoptysis was the predominant symptom among patients with chronic pulmonary aspergillosis (66.6%). Necrotic mediastinal lymph nodes had good diagnostic accuracy of 88.71% with area under the curve of 0.806, P < 0.001 in diagnosing recurrent TB. BAL GeneXpert and mycobacteria growth indicator tube had good sensitivity (83.33% and 84.62%, respectively), specificity (100% for both), and excellent diagnostic accuracy (95.16% and 96.36%, respectively) for diagnosing recurrence in sputum negative and sputum scarce patient, (P < 0.001) when compared with composite reference standard. For culture-positive cases, BAL GeneXpert MTB/RIF had 100% sensitivity and 97.73% specificity in diagnosing recurrent PTB patients. Conclusion: The presence of mediastinal necrotic lymph node is the most accurate CT finding that can differentiate recurrent TB from post-TB sequelae. No other single chest CT scan finding had reliable diagnostic accuracy in comparison to microbiological tools in diagnosing recurrence among sputum negative or scarce previously treated PTB suspects.

Keywords

• bronchoalveolar lavage genexpert
• composite reference standard
• sputum scarce