This document discusses 5 cases of pulmonary tuberculosis presenting with various symptoms and radiographic findings. It provides details on the chest x-ray and CT scan images for each case. It also includes background information on the types of tuberculosis infection including primary TB, reactivation TB, and miliary TB. Common radiologic signs seen in TB are described, such as the tree-in-bud sign, lung nodules, and cavitations. Differential diagnoses and diagnostic criteria for pulmonary TB are also outlined.

1. MBBS (India), M.Med Radiology(UKM)
A.M. (Malaysia)
Columbia Asia Hospital – Bukit Rimau
(Shah Alam)

2. Pulmonary
Tuberculosis

3. Pulmonary tuberculosis
 Discovery of the specific infectious agent, the tubercle
bacillus (Mycobacterium tuberculosis) by Robert Koch
in 1882.
 Descriptions of airborne transmission of infection and
of reactivation of dormant infection in the 1960s by
Riley et al and Stead and
colleagues, respectively, furthered our understanding
of the spread and pathogenesis of this disease.
 In 1993, the World Health Organization declared TB to
be a global emergency.

4. Case 1
 A man presented with chronic cough. Occasional
haemoptysis. No previous illness before.
 Mantoux test - indurated area of 24mm.

5. Chest radiograph
 Small cavitations in the
left upper lobe with
fibrosis and nodular
opacities.

6. HRCT Thorax

7. Reconstructed 3D images
 Lung fibrosis.
 Small granulomas.
 Small lung cavitations.
 Patchy consolidation.

8. Case 2
 A 47 year-old man with chronic cough.
 Poorly controlled DM status.

9. Chest radiograph
 Cavitating pneumonia of
left upper lobe.
 Sputum AFB direct
smear is positive.

10. Case 3
 A 29 year-old lady with persistent cough for 1month.
 Delivered a baby 3 month ago.
 History of contact with pulmonary TB.

11. Chest radiograph
 Reticulo-nodular
opacities in both upper
lobes (right > left).
 Minimal fibrosis in right
lung apex.
 Sputum AFB: positive.

12. Case 4
 A 52 years-old gentleman with underlying DM.
 Presented with cough and fever for 2months duration.
 Admitted to hospital for haemoptysis.

13. Chest radiograph: A cavitating lung lesion in the superior
segment of left lower lobe.

14. CT Thorax
 In the superior segment
of left lower lobe – a lung
cavitation.
 4.6cm x 2.7cm in size.
 This lesion is
representing lung
tuberculoma.

15. CT Thorax – lung reconstruction
 tree-in-buds appearance
adjacent to the cavitating
lung lesion.

16. Case 5
 A 60 years old man of poorly controlled diabetis
mellitus presented with cough.
 No fever.
 No loss of appetite or loss of weight.

17. Chest radiograph
 Multiple lung nodules of
varying sizes
predominantly in lower
and mid lung fields
bilaterally.
 Patchy consolidation in
the right upper lobe.

18. CT Thorax – images in lung setting
Lung consolidation in right upper lobe.
Cavitating lung lesion in left upper lobe.
Nodular opacities in both lower lobes.

19. CT Thorax - images in lung setting
 Tree-in-buds in superior
segment of left lower
lobe

20. CT Thorax - images in lung setting
Spiculated multiple lung nodules in both lower
lobes. Some appearing as flame-shaped lung
lesions.

21. Differentials
 Pulmonary TB
 Metastases
 Thoracic Kaposi sarcoma.
 SPUTUM: AFB 3+.

22. Thoracic Kaposi Sarcoma

23. Case 6 – FOMEMA Screening

24. Discussion
 Types of TB infection.

25. Primary TB
 lungs are the primary organ of spread- accounting for
about 70% of cases.
 extrapulmonary infection generally occurs as a result
of hematogenous dissemination from a clinically
occult pulmonary focus.
 typically a self-limited infection.
 about 5% of adults and up to 60% of infected children
are asymptomatic.

26. Primary TB
 in a less competent host, the infection is walled off,
but the bacillus remains viable, but dormant for many
years.
 typically presents as a segmental or lobar
consolidation usually involving the lower lobes
(although any lobe may be involved) and the
appearance is often indistinguishable from bacterial
pneumonia.
 multifocal involvement is seen in 12-24% of cases.

27. Primary TB
 prevalence of lymphadenopathy is greatest in the
pediatric age group (about 90-96% of affected children
(4,6,7) and is seen in about 43% of adults.
 Pleural effusion is found in up to 40% of adults, but
only 5-10% of children with primary infection
(7). Pleural fluid cultures are positive in only 20-40%
of cases (pleural biopsy cultures are positive in 65-75%
of cases).

28. Primary TB
 Pleural effusion can be the only radiographic finding
indicative of primary TB infection in about 5% of
cases.
 Regression of radiographic findings is a slow processrequiring from 6 months to 2 years for resolution.

29. Primary TB
 Radiographic differentiation between active and
inactive disease can only be made reliably on the basis
of temporal evolution. The American Tuberculosis
Association requires that a radiograph remain
unchanged for a period of 6 months to indicate
stable/inactive disease.

30. Primary TB
 Computed tomography can detect the presence of
adenopathy, parenchymal consolidations, or evidence
of endobronchial spread not seen on plain film
radiographs.
 A normal chest radiograph has a high negative
predictive value for the presence of active TB.

31. Primary TB
 Common findings of infection in infants include
mediastinal and hilar adenopathy (seen in 90-95% of
cases.
 The adenopathy is usually unilateral and located in the
hilum or paratracheal region. On CT the nodes
demonstrate central necrosis with rim enhancement.
 Pulmonary tuberculosis can manifest as pulmonary
nodules mimicking lung metastasis.

32. Miliary (disseminated) TB
 Typical miliary lesions may not be visible for 3 to 6
weeks after hematogenous dissemination.
 CXR reveals micronodular densities (1-2mm) diffusely
throughout both lungs.
 HRCT demonstrates a combination of sharp and
poorly defined 1 to 3 mm nodules distributed
throughout the lungs and have no relationship to the
airways in their distribution. The nodules usually
resolve within 2-6 months with treatment.

33. Miliary (disseminated) TB

34. Reactivation or post-primary TB.
 Reactivation infection usually develops in the
apical/posterior segments of the upper lobes (83-85%
of cases) or superior segment of the lower lobes (1114% of cases).
 Patchy alveolar infiltrate.
 The cavities typically have thick, irregular walls which
become smooth and thin with successful treatment.

35. Reactivation or post-primary TB
 Hilar or mediastinal adenopathy is unusual in
reactivation TB.
 An effusion may be the sole manifestation of
reactivation TB.

36. Tuberculous airway disease
 CT of the chest during active infection will
reveal irregular tracheobronchial narrowing and wall
enhancement with I.V. contrast. The mediastinal fat
around the trachea often demonstrates increased
density consistent with inflammation.

37. Chronic tuberculous empyema
 On CXR there is usually a moderate to large loculated
pleural fluid collection with pleural calcification and
enlargement of the overlying ribs.
 CT demonstrates the loculated pleural fluid
surrounded by a thick, calcified pleural rind.

38. Chronic tuberculous empyema
 loculated pleural fluid
collection in right lower
lateral hemithorax.
 Surrounding pleural
thickening and
calcifications.

39. Tuberculoma
 Well defined or have irregular margins and mimic a
lung neoplasm.
 Most lesions are less than 3 cm in size and calcification
can be seen in 20-30% of cases (usually nodular or
diffuse).
 Small satellite nodules about the larger lesion can be
found in up to 80% of cases.

40. Tuberculoma
 Tuberculoma seems to be round or polygonal shape
and primary lung cancer is more likely to be lobulated
shape. The smooth border nodule is found only in
tuberculoma (27%) whereas 93% of primary lung
cancer had spiculated border compared to 73% among
tuberculoma (p < 0.05).

41. Tree-in-bud sign on HRCT

42. Tree-in-bud sign on HRCT
 a finding seen on thin-section computed tomographic
(CT) images of the lung.
 Peripheral (within approximately 3–5 mm of the
pleural surface).
 small (2–4 mm in diameter), centrilobular, and welldefined nodules of soft-tissue attenuation are
connected to linear, branching opacities that have
more than one contiguous branching site.
 Resembling a tree in bud.

43. Tree-in-bud sign on HRCT
 represents bronchiolar luminal impaction with mucus,
pus, or fluid.
 dilated and thickened walls of the peripheral airways
and peribronchiolar inflammation.
 descriptive term for various diseases.
 the appearance of the tree-in-bud sign is closely linked
to the anatomy of the secondary pulmonary lobule.

44. Tree-in-bud sign on HRCT
 has primarily been used as a descriptive term for
abnormalities found on CT scans of the lung in
patients with endobronchial spread of Mycobacterium
tuberculosis .
 Pulmonary infectious disorders involving the small
airways are the most common causes of the tree-inbud sign. Any infectious organism, including bacterial,
mycobacterial, viral, parasitic, and fungal agents.

45. Tree-in-bud sign on HRCT
 Also with immunologic disorders, cystic
fibrosis, neoplasms, aspiration of irritant
substances, and disease entities with idiopathic causes.
 almost invariably points to inflammatory disease of
the small airways.

46. Lung nodules
 Benign if they:
 * Show little or no growth for 2 years
 * Calcification
 Central, laminated or diffuse pattern indicates a granuloma
 Eccentric calcification can be seen in a carcinoma or in a
cancer that has engulfed a granuloma.

47. Lung nodules
 Granulomas and lung cancer are by far the two most
common causes for a pulmonary nodule.
 Incidental small pulmonary nodules, especially less
than 5 mm, are an extremely common finding on chest
CT in the population over age 50.

48. Lung nodules
 The current recommended follow-up of incidental





pulmonary nodules per the Fleischner Society 2005 is
given below.
Low Risk Patient:
≤ 4mm: No follow-up needed.
4-6mm: 12 mo; if no change – stop.
6-8mm: 6-12 mo; no change - follow-up at 18-24 mo.
> 8mm: CT follow-up at 3, 9, 24mo or PET/CT, or
biopsy.

49. Lung nodules
 High Risk Patient (eg. smoking history or history of




malignancy).
≤ 4mm: 12 mo; if no change – stop.
4-6mm: 6-12mo; no change - follow-up at 18-24 mo.
6-8mm: 3-6mo; no change - follow-up at 18-24 mo.
> 8mm: CT follow-up at 3, 9, 24mo or PET/CT, or
biopsy

50. Background radiation – June 2006

51. Typically, CT of …
 the chest CT gives a radiation dose equivalent to 400 chest
radiographs.
 Chest tomography 8 mSv.
 Chest radiography=0.02 mSv.

52. References
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2. Radiology 1999; Leung AN. Pulmonary tuberculosis: The essentials. 210: 307-322.
3. AJR 2008; Jeong YJ, Lee KS. Pulmonary tuberculosis: up-to-date imaging and management.
191: 834-844
4. Radiographics 2007; Burrill J, et al. Tuberculosis: a radiologic review. 27: 1255-1273
5. Radiology 1999; Leung AN. Pulmonary tuberculosis: The essentials. 210: 307-322
6. Society of Thoracic Radiology Annual Meeting 2000 Course Syllabus; Leung AN.
Pulmonary tuberculosis. 83-84.
7. Radiol Clin N Am 2005; Tarver RD, et al. Radiology of community-acquired pneumonia.
43: 497-512.
8. AJR 1997; 168-1005-1009.
9. Society of Thoracic Radiology Annual Meeting 2000 Course Syllabus; Leung AN.
Pulmonary tuberculosis. 83-84
10. Radiographics 2001; Kim Hy, et al. Thoracic sequelae and complications of tuberculosis.
21: 839-860