Analysis of chest CT in patients with Mycobacterium avium complex pulmonary disease

The radiographic changes of Mycobacterium avium complex (MAC) pulmonary disease during therapy have not been studied well.

To assess the efficacy of antituberculous drug therapy against MAC pulmonary disease using computed tomography (CT).

We analyzed chest CT scans before and after antituberculous therapy in 30 patients (21 women, 9 men) with MAC pulmonary disease. To evaluate radiographic changes during therapy, we defined a 'degree of improvement' (DI) that is calculated according to the CT appearance.

DI was better (1.35 +/- 0.21) in patients who had converted sputum culture than in those who had not (0.44 +/- 0.25) (p < 0.05). In patients who were diagnosed by bronchial washing, DI was better (1.60 +/- 0.22) than in patients who were diagnosed by sputum (0.67 +/- 0.20) (p < 0.01). We categorized the CT appearance into 6 types: small nodules, cavities, bronchial wall thickening, infiltration, pleural thickening and atelectasis. Patients who showed pleural thickening had a significantly worse DI (0.12 +/- 0.40) than those who did not (1.23 +/- 0.18) (p < 0.01). Most of the lesions that disappeared after therapy were small nodules.

These results indicate that chest CT might be a useful tool for the prediction or assessment of drug therapy for MAC pulmonary disease.