It is uncommon for the bullae to be completely outlined by this tissue. Tuberculosis Epidemiological studies have demonstrated a rise in the incidence of tuberculosis in the last decade both in immunocomprimised and immunocompetent individuals. This is an important infection because it is contagious and can have serious long term consequences. Tuberculosis is only transmissible from human to human. Also, it in many cases has characteristic radiographic appearances which make the CXR an important surveillance tool.
Tuberculosis has a variety of stages of disease which have different radiographic appearances.
Initially, tuberculosis is acquired by inhalation of aerosolized droplets while in close proximity to an infected individual. Because the primary infection is caused by inhalation, the focus of infection may be in any region of the lung. This appears as a focal alveolar opacity, similar to any bacterial pneumonia. Ipsilateral hilar and mediastinal adenopathy may develop as the infection persists. The normal host immunity is able to contain the infection but not eradicate it.