Diagnostic Accuracy of Low-Dose CT Versus Chest X-Ray for Early Detection of Pulmonary Tuberculosis in High-Burden Districts of Balochistan.

Abstract

Background:
Pulmonary tuberculosis (TB) remains a global health challenge, particularly in high-burden, low-resource settings such as Balochistan. Early and accurate diagnosis is essential to control disease transmission and improve outcomes. Conventional chest X-ray (CXR), though widely used, has limited sensitivity for early-stage disease. Low-dose computed tomography (LDCT) offers improved image resolution with minimal radiation exposure, presenting a potential diagnostic advantage.

Objective:
To compare the diagnostic accuracy of LDCT and CXR for early detection of pulmonary tuberculosis in high-burden districts of Balochistan, Pakistan.

Methods:
A multicentric cross-sectional study was conducted in private hospitals across Quetta, Gwadar, and Sui over six months. A total of 270 suspected TB patients were enrolled, of whom 262 completed both imaging modalities and Gene-Xpert confirmation. Radiological findings were independently interpreted by blinded radiologists. Diagnostic performance parameters, including sensitivity, specificity, predictive values, and accuracy, were analyzed using SPSS version 26. Receiver Operating Characteristic (ROC) curves were generated to compare diagnostic capacities.

Results:
Out of 262 participants, 128 were confirmed TB cases. LDCT demonstrated a sensitivity of 92.9% and specificity of 89.2%, compared to 75.7% and 80.5% for CXR, respectively. The overall diagnostic accuracy was 91.9% for LDCT and 77.8% for CXR (p<0.001). LDCT identified subtle lesions, including small cavities and tree-in-bud patterns, missed by CXR. The mean radiation dose for LDCT was 1.27 mSv, remaining within international safety limits.

Conclusion:
LDCT provides superior diagnostic accuracy over CXR for early pulmonary TB detection while maintaining low radiation exposure. Its integration into diagnostic pathways in high-burden settings could significantly enhance early case detection and improve TB control outcomes.

Keywords:
Balochistan, Chest X-Ray, Diagnostic Accuracy, Low-Dose Computed Tomography, Pulmonary Tuberculosis, Radiography, Sensitivity and Specificity