1. Lung Nodules Frans Naudé

2. Definition of Pulmonary nodule Rounded opacity, moderately well defined < 3cm in diameter Web p 97

3. General Approach to lung nodules Position Is it a lung nodule? – Skin tags, nipple shadows, bone lesions Distribution in the lung Number of Nodules ( SPN, Multiple) Compare with previous radiographs Interpreting CXR p102

4. Web p185

5. P84, Computed Tomography of the Lung, Verschakelen

6. Lung nodules: Imaging Modalities CXR CT ( HRES) PET/CT : F18-FDG

7. Description of pulmonary nodule Pattern of distribution (Relationship to fissures, pleura, secondary lobules) Edge characteristics (sharp, poorly circumscribed, ground glass) Morphology ( branching/ tree in bud) Size: – Pulmonary nodule <3cm – Small nodule < 1cm Web p97 High resolution CT of the lung

8. Large nodules 1-3cm (Easily seen on CXR)

9. HRES CT Anatomy of pulmonary lobule

10. (1) interlobular septa (2) centrilobular region (3) lobular lung parenchyma Secondary pulmonary lobule Blue = Pulmonary veins Green = lymphatic's Yellow= bronchiolar branches Red = Arteries White = Connective tissue Computed Tomography of the lung p9

11. Secondary pulmonary lobule Prof Naidich

12. HRES CT Interstitial nodules vs Air space nodules

13. WEB-Algorithmic approach to nodules InterstitialAir space Well definedIll defined Soft tissue attenuationHomogenous soft tissue Obscure edges of vessels they touch Hazy and less dense than adjacent vessels Peripheral in Pulm. LobuleCentral P120 High resolution CT lung,Web - approach

14. CT of the lung, p74

15. CT of the lung, p72

16. HRES CT High resolution CT lung,Web – Algorithm 4

17. Airspace nodules = centrilobular distribution = no pleural/septal nodules Ground-glass opacification/ less dense than adjacent blood vessels

18. Centrilobular nodules : Tree in Bud

19. Tree – in - Bud PT with TB Indicative of endobronchial spread P83, Computed Tomography of the Lung,Verschakelen

20. Infective bronchiolitis  Tree in Bud appearance  Bronchial wall thickening Computed Tomography of the Lung,Verschakelen

21. HRES CT Tree in bud absent High resolution CT lung,Web - approach

22. Centrilobular: Tree in bud absent

23. Poorly defined hazy ground glass nodules Respiratory bronchiolitis Langercell histiocytosis Lymphocytic interstitial pneumonitis

25. Interstitial nodules = pleural/ septal predominance

26. HRES CT Perilymphatic High resolution CT lung,Web - approach

28. Perilymphatic disease Clustered nodules Adjacent to fissures and pleural surfaces and along central vascular structures DDX: Sarcoid, silicosis, CWP. Rare: Amyloid,LIP

29. Sarcoidosis P83, Computed Tomography of the Lung,Verschakelen

30. Silicosis Web p305

31. Web p 306

32. Coal workers pneumoconiosis Web p 306Diffuse pattern more in favour of CWP or silicosis than sarcoidosis

34. HRES CT Random High resolution CT lung,Web - approach

36. Random nodules Sharply define,+- feeding vessel DDX 1.Metastases: lung, breast, kidney, colon, melanoma, thyroid, pancreas 2.Infection: Milliary TB, septic emboli, fungal infection 3.Vasculitis 4.Langercell histiocytosis

37. Metastases Random Basilar predominance P82, Computed Tomography of the Lung,Verschakelen

38. CT of the lung, p 75

39. Perilymphatic vs. centrilobular TB Centrilobular changes : nodules, tree-in- bud, branching lines Sarcoidosis - Fissural and subpleural nodules

40. (A)Perilymphatic nodules. Nodules are immediately in contact with interlobular septa and the visceral pleura (B) Centrilobular nodules. Nodules are positioned 5 - 10 mm from costal and visceral pleural surfaces and interlobular septa.

41. High resolution CT lung,Web - approach

42. References High resolution CT of the lung, Web, Naidich CT of the lung, Verschakelen, De Wever Prof Naidich RSSA lecture High-Resolution CT of the Lung: Patterns of Disease and Differential Diagnoses, Radiol Clin N Am 43 (2005) 513 – 542 Imaging of Interstitial Lung Disease, Radiol Clin N Am 43 (2005) 589 – 599

43. SPN Def: focal area of increased round /oval density in the lung parenchyma measuring less than 3cm, Cause : infection, malignancy, inflammation, vascular, congenital Risk : 30-40% malignant

44. Radiographics 2000:20: 43

45. Approach to SPN Morphology: - Size ( smaller more likely benign) - margins and contours MarginsRisk for malignancy Smooth21% Lobulated ( uneven  growth75% Irregular,spiculated, distortion of blood vessels Very high risk

46. Internal characteristics Homogeneous attenuation (55% benign, 20%malignant) Pseudocavitation and air bronchograms: lymphoma or bronchioalveolar cancer Benign cavitation : smooth,thin walls (<4mm) Malignant cavitation: thick irregular walls( >16mm) Intranodular fat = hamartoma Benign calcification : – post infection: central, diffuse solid, laminated, – hamartoma : popcorn like Malignant calcification: diffuse,amorphous,punctate Metastatic osteosarcoma: high attenuation nodule

47. 25-39% malignant nodules classified as benign on radiological morphology assessment growth rate assessment: doubling rate ( increase in diameter of >26%) for malignant nodules between 30-400 days Clinical data: age, risk factors, previous malignancy

48. Distribution of lung nodules Cancer – basal predominance Breast CA, Colon, Renal often metastasize to lung Interpreting CXR p100

49. Size of lung nodules Mayo clinic CT screening trial ( in patients with no history of cancer) <3mm = less than 0,2% malignant <5mm = fewer than 1% malignant 4-7mm = 0,9% malignant 8-20mm = 18% malignant >20mm = 50% malignant Radiology Nov 2005 p 397

50. Follow-up National Lung Screening Trial nodules smaller than 4mm return for screening after 12 months, without interval scans or other work-up Radiology Nov 2005 p 397

51. Radiology Nov 2005 p 398