Comparison of lung ultrasound findings in patients with pulmonary tuberculosis and lobar pneumonia: a case-control study.

Background: The utility of Lung ultrasound (LUS) in the diagnosis of respiratory disorders has evolved in the recent past. Aim and objectives: To describe the ultrasound features of newly diagnosed pulmonary tuberculosis infection and compare them to the ultrasound features of pneumonia. To compare the LUS findings with chest Xray findings. Method: Subjects 18 to 65 years of age and recently diagnosed with tuberculosis or pneumonia in a tertiary care hospital underwent ultrasound evaluation after written informed consent. Results: A total of 96 subjects with 64 microbiologically confirmed TB and 32 pneumonia patients were included. The mean age of the study subjects was 46.78± 15.75 years and the majority were males(64.6%). LUS showed focal interstitial pattern, cavity, and irregular pleura in TB patients that were significantly different (p-value= <0.001)from the findings of air bronchogram and/or shred sign seen in patients with pneumonia (Table1). The time taken to complete LUS ranged from 3 to 6 minutes. The overall sensitivity of USG against X-ray was 88.6% and specificity was 0. Discussion: The composite findings of focal interstitial pattern, cavity, and irregular pleura seen in TB patients were significantly different from the findings of air bronchogram and/or shred sign seen in patients with pneumonia. The LUS and CXR findings were concordant in more than 73% of both pneumonia and TB patients. LUS demonstrated abnormalities in 20.3%  of TB patients whose CXR had no demonstrable opacities. Conclusion: LUS is a valuable tool to detect both TB and pneumonia and can discriminate between the two conditions.