Computed tomography features of extensively drug-resistant pulmonary tuberculosis in non-HIV-infected patients

To describe the computed tomography (CT) findings of pulmonary extensively drug-resistant tuberculosis (XDR-TB) in non-HIV-infected patients and to compare them with those of non-XDR multidrug-resistant tuberculosis (MDR-TB).

Retrospective review of microbiological results and drug-susceptibility tests of 260 non-HIV-infected patients who had been diagnosed with pulmonary MDR-TB from 1994 to 2005 revealed that 47 patients had XDR-TB, whereas the other 213 patients had non-XDR MDR-TB. Twenty of the 47 XDR-TB patients and 85 of the 213 non-XDR MDR-TB patients with available CT examinations were included in this study. Two radiologists reviewed the CT studies in consensus for the presence and extent of micronodules, tree-in-bud appearance, lobular consolidation (<2 cm), consolidation, cavity, bronchiectasis, emphysema, pleural effusion, lymphadenopathy, bronchopleural fistula, and empyema. We then compared the CT features of XDR-TB with those of non-XDR MDR-TB.

Micronodules and tree-in-bud appearance were the most frequent CT abnormalities and were seen in all XDR-TB patients (100%). Consolidations, cavities, bronchiectasis, and lobular consolidations were found in 85%, 85%, 80%, and 70% of XDR-TB patients, respectively. The extents of micronodules, tree-in-bud appearance, lobular consolidation, consolidation, cavity, bronchiectasis, and emphysema were 3.60, 3.55, 1.35, 1.85, 1.65, 1.45, and 0.25 lobes, respectively. Compared with non-XDR MDR-TB, XDR-TB showed a significantly larger extent of tree-in-bud appearance and consolidation (P < 0.05). With respect to other CT features, there were no significant differences between XDR-TB and non-XDR MDR-TB.

Computed tomography findings of pulmonary XDR-TB are similar to those of non-XDR MDR-TB; however, XDR-TB tends to have more extensive consolidation and tree-in-bud appearance.