Radiological features of tuberculosis

In primary tuberculosis:

• less than half of patients show radiological abnormalities
• there may be hilar lymph node enlargement; this subsides as immunity to the tubercle bacillus develops
• the hilar nodes or the Ghon focus may be calcified

In post-primary tuberculosis the radiological appearance is variable, including features such as:

• patchy solid lesions
• cavitated solid lesions
• streaky fibrosis
• flecks of calcification
• solitary tuberculoma presenting as a coin lesion
• hilar node enlargement

Classically, in miliary tuberculosis there are millet-sized nodules present throughout the lung fields, in practice, the chest radiograph is often normal.