Tuberculous Pneumonia and Bacterial Pneumonia in Diabetic Patients: Comparison of CT Findings

ABSTRACT

PURPOSE: To compare the CT findings of tuberculous pneumonia (TBPN) with those of bacterial pneumonia (BAPN) in diabetic patients and to evaluate the usefulness of CT in the differential diagnosis of these two diseases. MATERIALS AND METHODS: The chest CT scans of 23 diabetic patients with TBPN (MF=212; mean age, 59 yrs.) and of 37 diabetic patients with BAPN (MF=2116; mean age, 63 yrs.) were evaluated by two radiologists with regard to low attenuation areas in regions of consolidation, cavities, air bronchogram, volume changes, ground-glass attenuation, findings of bronchogenic spread, and other associated findings. The involvement of each segment was recorded in all patients. RESULTS:The frequencies of multiple small low-attenuation areas in regions of consolidation (52%, 0%), multiple cavities (35%, 3%), loss of volume (70%, 30%) and findings of bronchogenic spread (96%, 30%) were significantly higher in TBPN than in BAPN (p<.05). Low-attenuation masses and bizarre-shaped cavities were noted only in TBPN. Large areas of ground-glass attenuation (4%, 38%) and bilateral pleural effusions (0%, 19%) were more common in BAPN, while air-bronchogram was common in both groups (96%, 86%). The involvement of the superior segment was significantly more common in TBPN (p<.05). CONCLUSION: In the diabetic patients with pulmonary consolidation, CT findings of multiple small low-attenuation areas, multiple cavities, bizarre-shaped cavities, low attenuation masses in cavities, volume loss, and findings of bronchogenic spread are more suggestive of TBPN, while large areas of ground-glass attenuation and bilateral pleural effusions are more suggestive of BAPN. CT may be useful in the differential diagnosis between TBPN and BAPN.