Review Imaging: CXR & Chest CT

Triad of classic findings are seen in non-immunocompromised adults:

• Position – apical-posterior segments of upper lobes or superior segment of lower lobes in 90%

• Volume loss – this is a hallmark of TB disease as a result of its destructive and fibrotic nature

• Cavitation – this is seen at a later stage and depends upon a vigorous immune response; may not be
  seen in severely immunocompromised individuals

These may be seen in patients with immunocompromising conditions such as HIV infection, diabetes, renal failure, or corticosteroid use:

• Hilar and mediastinal lymphadenopathy, particularly in HIV infected individuals

• Non-cavitary infiltrates and lower lobe involvement

• Normal CXR in 10% of patients with HIV co-infection