Unilateral lower lung field opacities on chest radiography: a comparison of the clinical manifestations of tuberculosis and pneumonia.

Background: The radiological manifestations of lower lung field (LLF) tuberculosis (LLFTB) are similar to those of LLF pneumonia (LLFP), making diagnosis challenging. The aim of this study was to determine if there are differences in the clinical manifestations of LLFTB and LLFP in patients with unilateral LLF opacities.

Methods: We performed a retrospective review of patient records to identify those with unilateral LLF opacities who were subsequently diagnosed with LLFTB or LLFP. We compared demographics, clinical manifestations, hematological data, and radiographic findings between the groups of patients.

Results: We identified 22 and 72 patients diagnosed with LLFTB and LLFP, respectively. Multivariate analysis revealed that age (odds ratio [OR]=1.05, 95% confidence interval [CI]=0.99-1.11, P=0.072), lack of fever>38°C (OR=9.04, 95% CI=1.69-48.40, P=0.001), duration of symptoms≥7 days (OR=4.57, 95% CI=1.09-19.26, P=0.038), and the lack of air bronchograms upon radiography (OR=12.08, 95% CI=1.98-73.64, P=0.007) were significant predictors of LLFTB in patients with LLF opacities. We used these predictors to construct a mathematical model for predicting LLFTB in patients with LLF opacities.

Conclusions: Our findings suggest that older age, prolonged duration of symptoms, lack of fever>38°C, and the absence of air bronchograms are more common in patients with LLFTB than patients with LLFP. These findings may help clinicians differentiate between LLFTB and LLFP and thus initiate timely and appropriate treatment.