Pulmonary tuberculosis associated with the reversed halo sign on high-resolution CT

Abstract

We describe the case of a 32-year-old woman with pulmonary tuberculosis in whom a high-resolution CT scan demonstrated the reversed halo sign. The diagnosis of tuberculosis was made by lung biopsy and the detection of acid-fast bacilli in the sputum smear and culture. Follow-up assessment revealed a significant improvement in the lesions.

Figure 1

A high-resolution CT scan showing patchy consolidations and ground-glass opacities in both lungs, with a cavitation in the right upper lobe (a). Opacities with central areas of ground-glass attenuation surrounded by denser crescentic consolidations of at least 2 mm thickness (reversed halo sign; arrows) are seen in the lower lobes (b,c). These areas are admixed with poorly defined nodules. No lymphadenopathy is evident.

Figure 2

A follow-up high-resolution CT scan, obtained three months after the first examination with scans of the same level of Figure 1b (a) and Figure 1c (b), shows significant improvement in the opacities.