Tuberculosis radiology

1. Tuberculosis
(TB)

2. Tuberculosis (TB)
• TB caused by Mycobacterium tuberculosis.
• Remains an important disease & significant
problem in developing countries.
• Initial TB - 1st exposure:
• 1) Contained disease
• 2) Primary tuberculosis
• Reactivation (post-primary) TB
• Healed TB
• Miliary TB

3. Initial TB - 1st exposure:
• Initial exposure to TB can lead to two
clinical outcomes:
1) Contained disease (90%) occur in a
patient with normal immunity, results in:
– calcified granulomas and/or
– calcified hilar lymph nodes.
2) Primary tuberculosis seen more commonly
in children and immunocompromised patients.
Results when the host cannot contain the
organism.

4. Primary tuberculosis
• Primary tuberculosis represents infection from
the first exposure to TB.
• Primary TB may involve the pulmonary
parenchyma, the airways, and the pleura.
Primary TB often causes adenopathy.
• As many as 15% of patients infected with
primary TB have no radiographic changes
and the imaging appearance of primary
tuberculosis is nonspecific.

5. • Four imaging manifestations of primary TB (any, none, or
all of them may be seen):
– Ill-defied consolidation
– Ghon focus: complex small focal lesion with focal
calcification.
– Lymphadenopathy: common in primary TB.
– pleural effusion
– Miliary disease.
– Cavitation is rare in primary TB
• Primary TB may occur in any lobe, but the most typical
locations are the lower lobes or right middle lobe.

8. Reactivation (post-primary) TB
• Usually occurs in adolescents and adults and is
caused by reactivation of a dormant infection
acquired earlier in life.
• Clinical manifestations of reactivation TB
include:
– chronic cough
– low-grade fever
– hemoptysis, and
– night sweats.
• Reactivation TB most commonly occurs in the
upper lobe apical and posterior segments

9. Reactivation (post-primary) TB
• In an immunocompetent patient, the
imaging hallmarks of reactivation TB are:
– Focal upper lobe consolidation
– Cavitation
– No lymphadenopathy.

13. Healed tuberculosis
• Healed TB is evident on radiography as:
• apical scarring, usually with upper lobe
volume loss
• superior hilar retraction.

16. Miliary tuberculosis
• Miliary tuberculosis is a diffuse random
distribution of tiny nodules seen in
hematogenously disseminated TB.
• Miliary TB can occur in primary or
reactivation TB.

19. DDx of Miliary Shadow
• Miliary TB
• Silicosis
• Coal worker pneumoconiosis
• Sarcoidosis
• Metastasis