Characteristics of Consolidation, Centrilobular Nodule and Bronchus as CT Findings for the Differentiation between Tuberculosis and Pneumonia

Purpose: To differentiate tuberculosis from pneumonia by computed tomography (CT) in cases difficult to diagnose clinically and radiologically. Materials and Methods: CT scans of 300 patients with tuberculosis and 234 patients with pneumonia were retrospectively analyzed. Parenchymal abnormalities, lymph nodes, pleural effusions and central bronchial narrowing were evaluated. The density of consolidation was measured by pre- and post-enhanced CT. Results: Centrilobular nodules, granulomas, cavitations in both nodules as well as consolidation, conglomerated nodules, and enlarged lymph nodes occurred with significantly greater frequency in patients with tuberculosis than in those with pneumonia. Centrilobular nodules were larger and denser in tuberculosis patients. In consolidation, decreases in lung lobe volume and a bronchial beaded appearance (irregular narrowing and dilatation) were more frequent in patients with tuberculosis. The tuberculous consolidation had significantly lower mean enhancement and net enhancement than that from pneumonia. When the diagnostic criteria for tuberculosis were set as well-demarcated larger centrilobular nodules and/or a lowerly enhancing consolidation with internal beaded bronchi, the diagnostic accuracy was found to be 82.0%. Conclusion: Consolidation with a low level of enhancement, decreased lung lobe volume, and bronchi with irregular, beaded shape and denser and larger centrilobular nodules are helpful CT findings for the diagnosis of tuberculosis. KCI Citation Count: 0