CT findings of TB in diabetic and non-diabetic patients: A comparison before and after anti-tuberculous therapy

Objective: To evaluate the changes of pulmonary tuberculosis in diabetic and non-diabetic patients by CT scanning before and after anti-tuberculous therapy. Methods: Chest CT scans in 71 adult patients with active post primary tuberculosis were reviewed. Among them, 41 had no underlying disease, but 30 were diagnosed with diabetes mellitus. CT scans were performed before and after anti-tuberculous therapy. The initial CT findings as well as the findings in follow-up re-examinations were compared. Statistical analysis was performed using SPSS version 17.0 and p value < 0.05 was considered to be statistically significant. Results: Compared to non-diabetic patients, the diabetic patients showed a higher detection rate of lesions at the lower lung lobe (30.0% vs 17.1%; P < 0.05), non-segmental consolidation (26.7% vs 2.4%; P < 0.01), singular or multiple cavities within lesion (50.0% vs 30.7%; P < 0.01). However, the bud-in-tree sign (43.3% vs 61.3%), consolidation (76.6% vs 68.3%), nodules (63.3% vs 73.2%), ground glass opacity (16.7% vs 24.2%) and bronchiectasis (33.3% vs 41.7%) showed no statistical significance (p > 0.05). After 6 month anti-tuberculous therapy, the detection rate of most of the lesions by CT, such as consolidation, nodules, bud-in-tree sign, singular and multiple cavities, and pleural effusion, showed statistical significance (p < 0.05). But the diabetic patients had a slower and not obvious therapeutic response by CT scans. Conclusion: CT findings of tuberculosis in diabetic patients are different from those in non-diabetic patients, with a higher occurrence of non-segmental distribution and multiple cavities within a tuberculous lesion. By follow-up re-examination, diabetic patients show a slower and unobvious therapeutic response on CT scans compared to non-diabetic patients. CT can provide important information for the diagnosis and management of TB in diabetic and non-diabetic patients