CORRELATION OF RADIOLOGICAL FINDINGS WITH GENE EXPERT ANDE BACTERIAL LOADIN TB POSITIVE PATIENTS IN LAHORE, PAKISTAN

Abstract

Background: Tuberculosis (TB) remains a critical public health challenge, particularly in high-burden settings such as Pakistan. Accurate evaluation of bacterial burden and disease severity is essential for effective patient care and infection control. GeneXpert MTB/RIF, using cycle threshold (Ct) values, offers rapid semi-quantitative bacterial load estimation, while radiological imaging delineates the extent of pulmonary involvement.

Objective: To determine the correlation between chest radiological findings and GeneXpert-derived bacterial load in pulmonary TB-positive patients.

Methods: A cross-sectional analytical study was conducted on 100 GeneXpert-positive pulmonary TB patients. Radiological features including cavitation, consolidation, fibrosis, nodules, pleural effusion, and extent of lung involvement were systematically assessed and correlated with GeneXpert bacterial load categories and Ct values using Spearman rank correlation and chi-square tests.

Results: Patients with higher bacterial loads exhibited more severe radiological abnormalities, particularly cavitary lesions and extensive bilateral lung involvement. GeneXpert Ct values showed a strong inverse correlation with bacterial burden (ρ = −0.905, p < 0.001) and smear grade (ρ = −0.825, p < 0.001). Radiological severity increased proportionally with bacterial load categories. Conclusion: Radiological severity correlates significantly with GeneXpert bacterial burden in pulmonary TB. Combined use of chest imaging and GeneXpert testing enhances diagnostic precision, infectivity assessment, and disease monitoring. In resource-limited settings, radiological findings may serve as a practical proxy for bacterial load estimation