1. TB, Lung Abscess, and Cystic Fibrosis

2. TB Radiographic findings in primary TB are Nonspecific
Tends to like the lower lung zones
Cavitation is not as common in primary TB as in reactivation TB
However lymphadenopathy is a common finding in primary TB and uncommon in reactivation TB

3. TB
Patchy left lower lobe opacity
Looks like pneumonia

4. TB
Right upper and lower lobe consolidation
Right pleural effusion

5. TB Cavitary right upper lobe lesion Right paratracheal lymphadenopathy
Right middle lobe infiltrate
Notice the ipsilateral lymphadenopathy

6. TB
Thick walled cavity with satellite nodules
Smooth inner wall

7. TB Focal right middle lobe infiltrate Nodular like infiltrate
Endobronchial spread of TB
Adjacent areas of lung are infected by bronchial secretions

8. TB
Radiographic findings usually present 2 years after initial infection
Infiltrates usually like the apical and posterior segments of upper lobes and superior segment of lower lobes

9. TB
CT scan through the upper chest shows a thick walled cavity with an air fluid level and surrounding infiltrate
Cavities result from caseous necrosis

10. TB Complications of TB cavities Mycetoma “fungus ball”
Rasmussen Aneurysm which is weakening of bronchial artery adjacent to a cavitary lesion

11. Rasmussen Aneurysm

12. TB Bilateral lung nodules resulting from endobronchial spread of TB
Right upper lobe cavity

13. Miliary TB Right paratracheal lymphadenopathy
Bilateral tiny uniform nodules
Diffuse pattern of nodules is due to hematogenous spread

14. Miliary TB

15. TB Key Points Imaging findings of primary TB are nonspecific
Primary TB differentiated from bacterial pneumonia by the presence of lymphadenopathy
Reactivation TB recognized by fibrocavitary disease and a history of prior exposure

16. TB Key Points
Inactive disease cannot be established without prior films
Primary TB tends to affect the lower lung zones while reactivation TB tends to affect the upper lung zones

17. Pneumococcal PNA Complications Lung necrosis Abscess formation
Often need clinical history to distinguish from TB

18. Lung Abscess Air fluid level within a large cavity
Can communicate with the pleura resulting in an empyema

19. Lung Abscess

20. Lung Abscess 54 year old male with cough and foul smelling sputum
Cavity within the superior segment of the left lower lobe
Common site for aspiration

21. Lung Abscess Irregular cavity Typically more posterior
Often has an air/fluid level within it
Often has surrounding infiltrate

22. Lung Abscess Cavity with air fluid level and foul smelling sputum
Anaerobic organisms often the cause of abscesses from aspiration

23. Lung Abscess Key Points
Typical radiographic appearance is an irregular cavity with an air fluid level
Lung abscesses from aspiration often occur in the posterior segments of upper lobes or superior segments of lower lobes
The wall thickness of lung abscesses progresses from thick to thin and irregular to well circumscribed

24. Cystic Fibrosis Abnormal sodium/chloride transport in exocrine tissues
Results in thick viscous mucus
Obstructs airways resulting in repeat infections and colonization
Airways dilate and cysts form from air trapping
Scarring from the repeated infections

25. Cystic Fibrosis
Hyperinflation
Upper lobe bronchiectasis
Tram tracking