Chest 3

Pulmonary tuberculosis (p72-75)

• Primary tuberculosis • Postprimary tuberculosis

• Primary tuberculosis : usually occurs in childhood.

• In primary tuberculosis an area of consolidation , develops in the periphery of the lung usually in the mid or upper zones. • Usually, the pulmonary shadow is small •

• but it may occasionally involve most the lobe. • Sometimes the pulmonary consolidation is often accompanied by visibly enlarged hilar or mediastinum lymph nodes (Fig.2.80a).

So, This combination of pulmonary consolidation and lymphadenopathy is known as the primary complex. The clinical features of the primary complex vary.

The majority of patients have few symptoms and the disease is usually not recognized. They remaind have fever, cough and malaise.

In most cases, whether treated or not, the primary complex heals and often calcifies. • A calcified primary complex often remains visible( 显著的 ) throughout life. •

Spread of infection. Spread of infection may occur: 1.via the bronchial tree, which appears radiologically as patchy lobar consolidation; it often involves more than one lob may be bilateral and frequently cavitates; 2.via the blood stream, resulting in miliary tuberculosis (Fig.2.80b) ,(p72).

Postprimary tuberculosis: (p72)

Postprimary tuberculosis: usually presents with cough, haemoptysis( 咯血 ), weight loss, night sweats or malaise.

1. The disease may be discovered on a

routine chest film. 2.Postprimary tuberculosis is usually confined to the upper posterior portions of the chest, namely the apical and posterior segments of the upper lobes ,and the apical segments of the lower lobes.

The initial lesions are: 1. multiple small areas of consolidation (Fig. 2.81a) : 2.maybe bilateral.

If the infection progresses the consolidations enlarge and frequently cavitate, Cavity could been seen as rounded pulmonary shadowing (Fig.2.81b). • If the diagnosis of cavitation are difficult , we may use tomography or CT. •

TB

The infection may undergo partial or complete healing at any stage. Healing occurs by fibrosis, often with calcification (Fig.2.82). But both fibrosis and calcification may be seen in the presence of continuing activity .

• Chronic fibrous cavitary tuberculosis

Pleural effusions are frequent, they often leave permanent( 永久的 ) pleural thickening which may calcify.

• Tuberculoma. • The term tuberculoma refers to a tuberculous granuloma in the form of a spherical mass, usually less than 3cm in diameter. • The edge is usually sharply defined and these lesions are often partly calcified. • Conventional or computed tomography may be needed to demonstrate the calcification. • Most tuberculomas are inactive, but viable tubercle bacilli （杆菌） may be present even in the calcified lesions.

• Smooth border • Calcification in the spherical lesion • Satellite lesion

Is the disease active?

An important role for radiology in patients with pulmonary tuberculosis is to try and determine whether the disease is active or inactive. This can be very difficult and is sometimes impossible.

Valuable diagnostic signs of activity are: 1.development of new lesions on serial films; 2.demonstration of cavities(p75).

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• Lobar pneumonia

• Lobular pneumonia

• Lung abscess