Tuberculosis of the trachea and main bronchi: CT findings in 17 patients.

OBJECTIVE: The purpose of our study was to describe the CT findings of tuberculosis of the trachea and main bronchi.

MATERIALS AND METHODS: Initial (n = 17) and follow-up (n = 7) CT scans were available from 17 patients (five men and 12 women; aged 25-82 years old) with tracheobronchial tuberculosis. The diagnosis of tuberculosis was based on bronchoscopic, microbiologic, or pathologic findings.

RESULTS: The trachea (n = 6), the right main bronchus (n = 6), and the left main bronchus (n = 4) were involved in 10 patients with actively caseating tuberculosis. These airways showed irregular (n = 11) or smooth (n = 4) circumferential narrowing and occlusion (n = 1). Also, the trachea (n = 2), the right main bronchus (n = 1), and the left main bronchus (n = 6) were involved in seven patients with fibrotic tuberculosis. These airways showed smooth (n = 4) or irregular (n = 3) circumferential narrowing and occlusion (n = 2). Mediastinitis (increased densities in mediastinal fat) was seen in four of 10 patients with active tuberculosis but not in any of the seven patients with fibrotic disease. Tracheal tuberculosis, which has always been associated with bronchial disease, involved the distal trachea and exceeded 3 cm in length. After the seven patients underwent initial scans and antituberculous chemotherapy, serial CT scans showed improvement in seven of 11 lesion sites: normalized airways (n = 4) or smoothing from irregular narrowing (n = 3). The remaining four sites showed no change.

CONCLUSION: On CT scans, actively caseating tracheobronchial tuberculosis showed circumferential and predominantly irregular luminal narrowing and mediastinitis. When fibrotic disease was found, a CT scan revealed equal distribution of smooth and irregular narrowing and less wall thickening than was seen in patients with active disease. On CT scans, tracheal tuberculosis involved the long segment of the distal trachea, a condition associated with bronchial tuberculosis.