A Comparative Evaluation of Radiographic and Computed Tomography Results in Patients With Lower Respiratory Tract Infections With Positive and Negative Sputum Cultures: A Retrospective Observational Study.

Abstract

Background and aim: There is limited data on the correlation between findings of lower respiratory tract infections detected by chest computed tomography but not by chest radiography and sputum culture results. The aim of this study is to evaluate the relationship among sputum culture results, chest radiographic findings and computed tomography outcomes in patients diagnosed with lower respiratory tract infections.

Materials and methods: Between January 2021 and September 2023, the clinical and radiological findings of patients diagnosed with lower respiratory tract infections, both those with and without positive sputum cultures, were retrospectively evaluated.

Results: In the studied cohort, 65.4% (n = 172) of the patients were male and 34.6% (n = 91) were female, with an overall mean age of 67.18 ± 13.77 years. On chest computed tomography, consolidation was observed in 39.53% (n = 34) of patients with positive sputum cultures, compared to 23.72% (n = 42) of patients with negative cultures (p = 0,005). Furthermore, necrotising pneumonia findings were noted in 5.81% (n = 5) of culture-positive patients and 1.13% (n = 2) of culture-negative patients (p = 0.034). Infiltrative changes were detected in 81.4% (n = 70) of patients with positive cultures and 66.6% (n = 118) of patients with negative cultures on chest radiography (χ² = 20,492; p < 0.001).

Conclusion: The identification of findings on chest radiography is notably challenging in patients diagnosed with lower respiratory tract infections due to the presence of non-consolidative infiltrates and their respective anatomical locations. Moreover, the probability of detecting radiological findings on chest radiographs is enhanced in patients exhibiting positive sputum cultures.