This document discusses how to report findings from HRCT scans of the lungs in patients with interstitial lung disease. It begins by describing the scanning technique and basic lung anatomy. It then outlines a systematic approach to interpretation, including recognizing patterns (reticular, nodular, increased/decreased opacity), locating abnormalities, and evaluating effects on lung parenchyma. Specific disease patterns and findings are discussed along with their typical causes. Golden rules for interpretation are provided. References for further reading are included.

1. HRCT chest in interstitial lung
diseases.
How to report like an expert
Dr/Ahmed Bahnassy
Consultant Radiologist
MBCHB-MSc-FRCR(UK)

2. Tribute to the pioneers

3. secondary pulmonary lobule

5. disease distribution according to
compartments

6. A-Perilobular pattern

7. 1

8. 2

9. 3

10. B-Centrilobular pattern

11. hypersensitivity pneumonitis

12. Bronchiolar infection

13. Centrilobular emphysema

14. C-panlobular pattern

15. peumonia

16. Lobular low attenuation

17. Headcheese sign-HP

18. Technique of HRCT and anatomy
• Very thin 1mm slices for chest with 10-20
mm intervals aiming at visualizing the lung
interstitium.

19. Road map to diagnosis
1. Recognize the abnormality pattern.
2. Locate the abnormality in relation to the
lung and to the SPL
3. Evaluate its effects on lung parenchyma

20. HRCT patterns-4 base of pyramid
• Reticular pattern
• Nodular pattern.
• Increased lung opacity.
• Decreased lung opacity and cystic
changes

21. Reticular

22. I-Reticular opacities
• Interlobular septal thickening:
• Causes :
1. Lymphangitic spread of
tumour (asymmetrical or
symmetrical)
2. Pulmonary edema.
3. Amyloidosis

23. Honeycombing
– Causes:
 IPF
 Collagen vascular diseases
(Rh.A. - scleroderma)
 Drug related fibrosis
 End stage Hypersensitivity
pneumonitis
 End Stage Sarcoidosis
 Radiation.
 End stage ARDS

24. Traction Bronchiectasis
• Causes :
1. Non specific
intersitial
pneumonia.
2. UIP
3. Sarcoidosis.
4. Hypersensitivity
pneumonitis.
5. Radiation.
6. End stage ARDS
• Corkscrewed bronchi
in IPF

25. I :Lymphangitic spread of tumour

26. II-Scleroderma

27. III-IPF
• Posterior lung cysts • Prone scan

28. IV-Rheumatoid arthritis-Dilated
bronchi=fibrosis

29. Disease pattern-smooth

30. Disease pattern-irregular

31. Nodular

32. II-Nodules
• Perilymphatic.
• Centrilobular.
• Random

33. A-Perilymphatic nodules
• Causes :
1. Sarcoidosis.
2. Silicosis.
3. Lymphangitic spread
of tumour.
4. Amyloidosis.
5. Lymphocytic
interstitial pneumonitis

34. I -Sarcoidosis

35. II-Lymphangitis carcinomatosis

36. B-Random nodules
causes :
1. Miliary infection
2. Haematogenous
metastasis.
3. Sarcoidosis

37. I-Miliary TB

38. II-Miliary mets

39. C-Centrilobular nodules
• causes :
1. Endobronchial spread of
infection (Bacteria, virus, TB,
mycobacterium, fungus)
2. Endobronchial spread of
tumor (BAC)
3. Hypersensitivity pneumonitis.
4. BOOP
5. Silicosis and coal miner
pneumoconiosis

40. Centrilobular nodules
I-Bronchopneumonia

41. II-Hypersensitivity pneumonitis

42. Tree – in – bud appearance
• Causes :
1. Endobronchial spread of
infection(bacteria,TB ,fungi)
2. Airway disease with
infection(CF ,bronchiectasis)
3. Mucous plugging(asthma
,ABPA)
4. BAC .

43. I-Cystic fibrosis

44. II-Air way infection

45. III-Pseudomonas
bronchopneumonia

47. Disease pattern-centrilobular

48. Disease pattern-Random

49. Disease pattern-perilymphatic

50. Alveolar opacification

51. III-Increased lung opacity
• Consolidation.
• Ground Glass
opacification

52. Consolidation causes.
• Acute Symptoms:
– Pneumonia
– Pulmonary edema,He.
– ARDS
• Chronic Symptoms :
– Chronic eosinophilic
pneumonia
– BOOP
– Interstitial pneumonia
– Lipoid pneumonia.
– BAC

53. Consolidation-I-Chronic eosinophilic
pneumonia: multifocal,patchy
subpleural areas of consolidation

54. II-BOOP:patchy GG opacity in peribronchial
distribution. (Here post transplant graft
versus host disease)

55. Ground Glass Opacity causes
• Acute Symptoms :
– Pulmonary edema,
He.
– Pneumonia.
– DAD
– AIP
– Acute Hypersensitivity
pneumonitis.
• Chronic Symptoms :
– NSIP
– UIP
– DIP
– Hypersensitivity
pneumonitis.
– Alveolar proteinosis.
– Sarcoidosis.
– Lipoid pneumonia.
– BAC

56. I-Pulmonary edema

57. II-CMV infection:GG opacities with
centrilobular nodules

58. III-Pneumocystis carinii infection

59. IV-Hypersensitivity pneumonitis

60. Crazy-paving pattern
• Combination of GG opacity
with interlobular septal
thickening.
• Non specific.
• Causes :
• PCP , viral pneumonia
,edema , hemorrhage
,ARDS .
• If chronic lung disease it is
often :alveolar proteinosis

61. Alveolar Proteinosis
• Fine reticular pattern + GG opacity

62. Disease pattern-acute

63. Disease pattern-chronic

64. tree in bud

65. Cystic decreased density pattern

66. IV-Decreased lung opacity and
cystic lesions .
1. Emphysema
(centrilobular,panlo
-bular ,paraseptal )
2. Mosaic perfusion.
3. Air trapping .
4. Lung cysts .

67. I-Centrilobular Emphysema

68. II-Panlobular Emphysema

69. III-Paraseptal Emphysema

70. Lung cysts
• Common
causes :
– Bullae
– Honeycombing.
– Pneumatocekes.
– Cystic
bronchiectasis.
– Cysts in
hypersensitivty
pneumonitis
• Uncommon:
• Lymphangioleio
myomatosis.
• LCH
• TS
• Sjogren
syndrome.
• LIP
• Papillomatosis

71. I-Lymphangiomyomatosis

72. II-LCH

73. Mosaic appearance
• causes :
• Airway Disease:
– Large air way (CF
,Bronchiectasis)
– Small air way (BOOP
,small air way
infection ,mucous
plugging)
• Vascular diseases :
– Chronic PE
– vasculitis

74. cluster of grapes

75. string of pearls

76. Honeycombing pattern

77. Random cysts

78. Common Interstitial lung
diseases-peak of the pyramid

80. UIP/IPF

81. Reticular opacities, traction
bronchiectasis + HC

82. NSIP=Nonspecific interstitial
pneumonia
• GG opacities +reticulations

83. COP- Peribronchial consolidations-
GG opacity

84. COP=Irregular nodular opacities

85. DIP-Desquamative interstitial
pneumonia

86. LIP=Lymphocytic interstitial
pneumonia

88. Golden rules for HRCT
interpretation.
• Honeycombing with a basal and subpleural redominance
is highly suggestive of UIP.Lung biopsy is rarely
performed when HRCT shows these findings.
• Concentric lower lobe GG opaity without honeycombing
suggests NSIP.In a patient with collagen vascular
disease ,biopsy is uncommoly performed.
• Patchy or noular subpleural or peribronchial
consolidation is typical of COP.
• Cystic air spaces or GG opacity may represent LIP.LIP is
usually associated with other diseases.
• Diffuse or centrilobular GG opacity in a smoker is typical
of DIP or RB-ILD

89. References
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lungs: high-resolution CT. Radiology 1988; 166: 81-87.
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