The document discusses various airway diseases seen on imaging. It covers benign and malignant tracheal tumors including papilloma, hamartoma, lipoma and squamous cell carcinoma. It also discusses chronic bronchial diseases such as COPD, emphysema, asthma and bronchiectasis. Non-neoplastic tracheal diseases described include saber sheath trachea, tracheopathia osteoplastica and tracheobronchomalacia. The document provides detailed information on the pathology and radiographic features of many common and rare airway diseases.

1. Chest
Airway Diseases

2. Mohamed Zaitoun
Assistant Lecturer-Diagnostic Radiology
Department , Zagazig University Hospitals
Egypt
FINR (Fellowship of Interventional
Neuroradiology)-Switzerland
zaitoun82@gmail.com

5. Knowing as much as
possible about your enemy
precedes successful battle
and learning about the
disease process precedes
successful management

6. Airway Diseases
a) Tracheal Diseases
b) Chronic bronchial Diseases
c) Upper Airway Obstruction in Children

7. a) Tracheal Diseases :
1-Neoplastic Diseases
2-Non-Neoplastic Diseases

8. 1-Neoplastic Diseases :
a) Benign
b) Malignant

9. a) Benign :
1-Incidence
2-Types

10. 1-Incidence :
-Only 10% of tracheobronchial tumors are
benign
-Benign tumors are typically < 2 cm

11. 2-Types :
a) Papilloma :
-Common laryngeal tumors in children
b) Hamartoma :
-Fat density is diagnostic
-Often calcified (popcorn pattern)
c) Lipoma :
-Rounded homogeneous fat attenuation lesion
-90 % in males
d) Adenoma :
-Rare

12. Papilloma

13. Small and well-defined posterolateral lesion projecting into
tracheal lumen , Papilloma

14. Hamartoma

15. Lipoma

16. CT+C (a) shows a low-attenuation (-5 HU) endobronchial nodule (black arrow)
in the bronchus intermedius , post-obstructive atelectasis of the right lower
lobe can be seen (white arrow) , CT (b) obtained at the level of the left
brachiocephalic vein shows a low attenuation (-95 HU) nodule in the trachea

17. b) Malignant :
1-Incidence
2-Types

18. 1-Incidence :
-90 % of all tracheobronchial tumors are
malignant

19. 2-Types :
a) Primary :
-SCC (most common)
-Adenoid cystic carcinoma (2nd
common)
-Mucoepidermoid
-Carcinoid

20. Chest X-ray showing lobulated lesion at the level of the carina (red arrow)

21. CT+C shows nearly complete central tracheal obstruction
with the tumor

22. Rounded mass at the level of carina causing significant reduction of the
lumen of both bronchi , Squamous cell carcinoma

23. CT shows the tracheal mass extending and obliterating the
right main bronchus

24. CXR (a) shows an upper right paratracheal opacity narrowing the tracheal
lumen (arrow) , CT+C (b) confirms the eccentric lobulated soft tissue mass
that origins from the right anterolateral tracheal wall and narrows the lumen
of the upper trachea , coronal MPR image at mediastinal window setting (c)
better depicts the entire extent of the lesion

25. Mediastinal mass arising from the posterolateral wall of the trachea (a
characteristic feature) with invasion of mediastinal fat and
esophagus , Cystic adenoid carcinoma

26. Adenoid Cystic Carcinoma

27. CT (a) shows an irregular thickening of the left tracheal wall with a
lobulated mass protruding into the tracheal lumen (arrow) , CT (b)
shows irregular thickening of the left posterolateral tracheal wall with
nodular intraluminal extension of tumor (arrow)

28. Carcinoid

29. b) Mets :
1-Local Extension (common) :
-Thyroid cancer
-Esophageal cancer
-Lung cancer
2-Hematogeneous Mets (rare) :
-Melanoma
Breast cancer

30. Direct extension to the tracheal lumen of anaplastic thyroid cancer

31. CT shows a large proximal esophageal mass with asymmetric
impression on the posterior tracheal wall suggestive of invasion

32. Irregular right lateral wall of the trachea secondary to direct extension from
small cell carcinoma of the lung

33. Tracheal and bronchial metastases from melanoma

34. 2-Non-Neoplastic Diseases :
1-Saber Sheath Trachea
2-Tracheopathia Osteoplastica (TPO)
3-Tracheobronchomalacia
4-Tracheobronchomegaly
5-Relapsing Polychondritis
6-Post-intubation Tracheal Stenosis

35. 7-Post-infectious Tracheal Stenosis & T.B.
8-Tracheobronchial Diverticula
9-Bronchial Anthracofibrosis
10-Amyliodosis
11-Wegner’s Granulomatosis
12-Tracheal / Bronchial Narrowing ,
Stenosis or Occlusion

36. 1-Saber Sheath Trachea :
a) Pathology
b) Radiographic Features

37. a) Pathology :
-Refers to diffuse coronal narrowing of the
intrathoracic portion of the trachea with
concomitant widening of the sagittal
diameter , extrathoracic segment of the
trachea is always preserved
-It is pathognomonic for COPD
-More common in males

38. b) Radiographic Features :
-Marked decrease in the coronal diameter of
the intrathoracic trachea associated with
an increase in its sagittal diameter
-Tracheal ring calcification is common

43. Saber-sheath trachea , notice sparing of extrathoracic trachea and coronal
narrowing of the intrathoracic segment

45. 2-Tracheopathia Osteoplastica (TPO) :
a) Pathology
b) Radiographic Features

46. a) Pathology :
-Foci of cartilage and bone develop in the
submucosa of the tracheobronchial tree
-Benign , rare condition
-Only affects the anterior and lateral walls
with sparing of the posterior membranous
portion

47. b) Radiographic Features :
-Calcified tracheobronchial tree , nodules ,
osteocartilaginous growth
-Thickening of tracheal cartilage
-Narrowed lumen
-Distal three fourths of the trachea and the
proximal bronchi are most commonly
involved

48. Diffuse stricture of the tracheal lumen due to an irregular
thickening of the lateral walls

51. 3-Tracheobronchomalacia :
a) Pathology
b) Radiographic Features

52. a) Pathology :
-Refers to weakening of tracheal and bronchial walls
-May be primary or secondary :
1-Primary (uncommon) :
-Occurs in children
-May be associated with laryngomalacia
2-Secondary (more common) :
-Ageing
-Prolonged intubation , especially in those with
tracheostomy
-COPD
-Chronic or recurrent infection

53. b) Radiographic Features :
-Collapsed walls of trachea and bronchi
-Inspiratory only CT is unable to make the
diagnosis
-Diagnosis usually requires airway assessment
after a forced expiration (Dynamic Expiration)
-A hallmark of TM is the frown sign, a crescent
bowing of the posterior membranous tracheal
wall at expiratory CT scans

54. On inspiration On expiration

55. Axial inspiratory CT (a,b) show a normal shape of the tracheal and bronchial
lumen , Expiratory CT (c,d) show a severe collapse of the airways with an
inward bowing of the posterior wall (frown sign) , mild air-trapping is also
evident in both lungs

56. Tracheomalacia in COPD patient , notice collapse of more than 50% of the
tracheal lumen in expiratory image on the right

57. Significant collapse on expiratory images (below) of trachea
and main bronchi , Tracheobronchomalacia

58. Significant collapse on expiratory images (below) of trachea and main
bronchi

61. 4-Tracheobronchomegaly :
a) Pathology
b) Radiographic Features

62. a) Pathology :
-Also known as Mounier-Kuhn syndrome
-Rare condition characterized by markedly
dilated airways leading to recurrent
infections
-It appears in young patients (third and
fourth decade)

63. b) Radiographic Features :
-Tracheobronchomegaly is diagnosed when
the tracheal diameter is bigger than 3 cm

64. Markedly enlarged trachea and main bronchi in asymptomatic man

65. CT shows severe dilatation of the trachea (a) and the right main stem bronchus
(b) associated with fibrotic consolidations and traction bronchiectasis in the
upper lobes , more evident on the right (a)

67. 5-Relapsing Polychondritis :
a) Pathology
b) Radiographic Features

68. a) Pathology :
-Recurrent inflammation of cartilaginous
structures including tracheal cartilages
-The etiology is unknown but it is likely
immune-mediated
-Tracheal involvement is present in half of
patients with a slightly higher prevalence
in women

69. b) Radiographic Features :
-Wall thickening with increased attenuation that
may range from a subtle increase to clear
calcifications
-A key fact for diagnosis is the preservation of the
posterior wall of the trachea formed by muscular
and fibrous tissue and lacking cartilaginous rings
, this particular appearance allows diagnosis
with a high degree of confidence

70. Tracheal wall thickening with calcifications involving anterior and lateral walls
with preservation of the posterior wall. Notice moderate and diffuse stenosis
of the tracheal lumen on the MIP image

71. Axial CT show smooth tracheal (a) and bronchial (b) wall thickening with calcifications ,
the typical sparing of the posterior membranous walls of the airways can be seen
(arrows)

72. 6-Post-intubation Tracheal Stenosis :
-The placement of endoluminal tubes in the
large airways may cause a reparative
fibrotic process at the cuff site (in tracheal
intubation) or at the stoma site (in
tracheostomy) leading to a tracheal
narrowing

73. CT (a) shows an eccentric stenosis of the subglottic tracheal lumen on the right
(arrow) , external VR image (b) along the long axis of the trachea better
depicts the stricture extent and the typical appearance of “hourglass” of the
trachea

74. 7-Post-infectious Tracheal Stenosis &
T.B. :
-Central airways may be involved in 10-40%
of cases of pulmonary parenchymal
tuberculosis by lymphatic spread or local
invasion from mediastinal affected lymph
nodes
-The most frequent site of stenosis is the
lower third of the trachea and the main
stem bronchi

75. CT (a,b) show enlarged lymph nodes (arrows) in the right paratracheal region and
subcarinal region that infiltrate distal trachea and right main bronchus walls
determining airway lumen narrowing , coronal CT reformation (c) and VR image (d)
better illustrate the extension of the lesions throughout the tracheobronchial tree

76. 8-Tracheobronchial Diverticula :
-May be congenital or acquired
-Congenital usually very small with a very
narrow communication with the airway ,
whereas the acquired is bigger and
usually have a wide communication with
the airway

77. Congenital diverticulum , Axial CT (a) show an air-filled right
paratracheal cyst (arrow) at the cervico-thoracic junction , coronal
MPR (b) better depicts the apparent communication (arrow) with the
tracheal lumen by a narrow neck.

78. Acquired diverticulum , Axial CT (a) and oblique MPR image (b) show a
large air-filled paratracheal cyst (arrow) at the cervico-thoracic
junction , the large dimension and the broad base are consistent
with an acquired diverticulum

79. Right paratracheal diverticulum , notice narrow connection
between diverticulum and tracheal lumen

80. 9-Bronchial Anthracofibrosis :
-Benign condition affecting more
frequently elderly women
-The term refers to the bronchoscopic
finding of dark anthracotic pigments in the
bronchial wall with subsequent bronchial
narrowing or obliteration in patients
without a relevant history of
pneumoconiosis or smoking

81. -The most commonly reported finding on CT
scans is lobar or segmental post-
obstructive atelectasis , multifocal
stenoses of lobar and segmental bronchi
with peribronchial soft tissue thickening
and calcified or noncalcified lymph nodes
may also be seen

82. CT+C (a) shows partial atelectasis of right upper lobe with smooth narrowing of right main bronchus
and obstruction of right upper lobe bronchus , an enlarged lymph node (arrow) adjacent to
involved bronchus can be seen , axial non-enhanced CT (b) shows obstructed right middle lobe
bronchus resulting in partial atelectasis of right middle lobe , calcified lymph nodes adjacent to
right middle lobe bronchus are also present (black arrows) , lingular segmental bronchus is
thickened with adjacent enlarged lymph nodes containing calcification (white arrow)

83. 10-Amyliodosis :
-Diffuse involvement of the tracheobronchial
tree beginning from the trachea and large
bronchi extending sometimes to
segmental bronchi
-CT shows multifocal , nodular or
circumferential wall thickening of soft-
tissue density with a smooth surface and
possible concentric calcifications

84. Axial CT (a,c) show diffuse circumferential and smooth wall thickening with mild
calcifications of the trachea , main stem bronchi and lobar bronchi bilaterally
, axial CT (b) shows an almost complete occlusion of the right upper lobar
bronchus with a distal chronic post-obstructive atelectasis of the anterior
segment of the right upper lobe (arrow)

85. Circumferential thickening of the tracheal wall with irregular
appearance in virtual bronchoscopy image

86. 11-Wegner’s Granulomatosis :
-Late complication of the disease
-CT shows focal or more often diffuse
circumferential wall thickening

87. Smooth subglotic wall thickening , Wegener granulomatosis

88. Asymmetric thickening of the tracheal wall progressing to significant lumen
stenosis of subglotic position , Wegener granulomatois

89. 12-Tracheal / Bronchial Narrowing ,
Stenosis or Occlusion :
a) In the Lumen
b) In the Wall
c) Outside the Wall

90. a) In the Lumen :
1-Foreign body
2-Mucus plug
3-Misplaced endotracheal tube
4-Broncholithiasis

91. b) In the Wall :
-See Before + Bronchial Atresia

92. c) Outside the Wall :
1-Lymph nodes
2-Mediastinal tumors
3-Enlarged left atrium
4-Aortic aneurysm
5-Anomalous origin of left pulmonary artery from right
pulmonary artery :
-Producing compression of the right main bronchus as it
passes over it between the trachea and esophagus to
reach the left hilum
-PA CXR shows the right side of the trachea to be indented
and the vessel is seen end-on between the trachea and
esophagus on the lateral view

94. Aberrant left pulmonary artery , aberrant artery extends between trachea &
esophagus indenting both (arrows)

95. b) Chronic Bronchial Diseases :
1-COPD
2-Emphysema
3-Bronchial Asthma
4-Bronchiectasis
5-Cystic Fibrosis
6-Bronchiolitis Obliterans

96. 1-COPD :
a) Pathology
b) Clinical Picture
c) Radiographic Features

97. a) Pathology :
-Represents a spectrum of obstructive airway diseases
-It includes two key components which are chronic
bronchitis and emphysema
-In contrast to asthma , the histologic changes of COPD
are irreversible and gradually progress over time
-In chronic bronchitis , there is diffuse hyperplasia of
mucous glands with associated hypersecretion and
bronchial wall inflammation
-Emphysema involves the destruction of alveolar septa and
pulmonary capillaries leading to decreased elastic recoil
and resultant air trapping

98. b) Clinical Picture : More in smokers
1-Blue Bloaters : Bronchitis
-Bronchitis , tussive type of COPD
-Episodic dyspnea due to exacerbation of bronchitis
-Young patients
-Cyanosis
2-Pink Puffers : Emphysema
-Emphysematous type of COPD
-Progressive exertional dyspnea due to the emphysema
-Elderly patients

99. c) Radiographic Features :
1-Plain Radiography
2-CT

100. 1-Plain Radiography :
-Findings of chronic bronchitis are
nonspecific and include increased
bronchovascular markings (dirty lung sign)
and cardiomegaly

101. CXR shows increased bronchovascular markings

102. Dirty Lung sign

103. -Emphysema manifests as lung hyperinflation with
flattened hemidiaphragms , a small heart and
possible bullous changes , on the lateral
radiograph, a "barrel chest" with widened AP
diameter may be visualized , the "saber-sheath
trachea" sign refers to marked coronal narrowing
of the intrathoracic trachea (frontal view) with
concomitant sagittal widening (lateral view)

104. CXR shows the signs of hyperinflation of the lungs (flattening of
hemidiaphragms , widening of retrosternal and retrocardiac spaces
green and yellow stars respectively) and loss of regular vascular
branching pattern

105. Bullous changes

106. Saber sheath trachea

107. 2-CT :
-In chronic bronchitis , bronchial wall
thickening and increased lung markings
(dirty lung appearance) may be seen ,
repeated inflammation can lead to
scarring with bronchovascular irregularity
and fibrosis

108. CT shows bronchial wall thickening

109. CT in patient with chronic bronchitis showing thickening of the bronchial
walls (red arrows) and mucous within the bronchi (yellow arrows)

110. -Emphysema is diagnosed by alveolar septal destruction
and airspace enlargement which may occur in a variety
of distributions
-Centrilobular emphysema is predominantly seen in the
upper lobes
-Panlobular emphysema predominating in the lower lobes
-Paraseptal emphysema tends to occur near lung
fissures and pleura
-Formation of giant bullae may lead to compression
of mediastinal structures while rupture of pleural blebs
may produce spontaneous pneumothorax /
pneumomediastinum

111. Centrilobular Emphysema

112. Panlobular Emphysema

113. Paraseptal Emphysema

114. Bullous Emphysema

115. CT shows a focal area of emphysema (yellow arrow) ,
pneumothorax (red arrow)

116. 2-Emphysema :
a) Pathology
b) Clinical Picture
c) Radiographic Features
d) Differential Diagnosis

117. a) Pathology :
-Abnormal enlargement of distal airspaces with destruction
of alveolar walls with or without fibrosis
-More in smokers
-There are three morphologic sub types of emphysema
which are named according to their relationship to
the secondary pulmonary lobule :
1-Centrilobular Emphysema :
-Is the most frequently encountered type and affects the
proximal respiratory bronchioles
-More in the upper zones
-It is strongly associated with smoking

118. 2-Panlobular Emphysema :
-Affects the entire secondary pulmonary lobule ,
more in the lower zones
-Seen particularly in alpha-1-antitrypsin (AAT)
deficiency (exacerbated by smoking)
3-Paraseptal Emphysema :
-Affects the peripheral parts of the secondary
pulmonary lobule near lung fissures and pleura
-It is also associated with smoking and can lead to
the formation of subpleural bullae and
spontaneous pneumothorax

120. Centrilobular Panlobular Paraseptal

121. Centrilobular Panlobular Paraseptal

122. b) Clinical Picture :
-The clinical features of emphysema should be
distinguished from the signs and symptoms
of chronic bronchitis
-Patients with emphysema often referred to as pink
puffers
-Patients with chronic bronchitis often referred to
as blue blotters
-However in clinical practice features of these two
syndromes coexist as chronic obstructive
pulmonary disease

123. c) Radiographic Features :
1-Plain Radiography
2-CT

124. 1-Plain Radiography :
a) Hyperinflation :
-Flattened hemidiaphragm(s) : most reliable sign , highest
level of the dome is <1.5 cm above a straight line drawn
between the costophrenic and the vertebrophrenic
junctions
-Increased and usually irregular radiolucency of the lungs
-Increased retrosternal airspace
-Increased AP diameter of chest
-Widely spaced ribs
-Sternal bowing
-Tenting of the diaphragm
-Saber sheath trachea

126. Normal Diaphragm Flattened Diaphragm

127. Normal Flattening of the diaphragm

128. Increased radiolucency , increased AP diameter of chest

129. Normal retrosternal space Increased

130. Normal Widely spaced ribs

131. b) Vascular changes :
-Decreased number of vessels in areas of
abnormal lung
-Absence of peripheral pulmonary vessels
-Fewer arterial branches
-Central pulmonary artery increased in size

133. Hyperlucency of the lungs with fewer vascular
markings and prominence of the pulmonary
arteries (arrows)

134. 2-CT : In all three sub types, the emphysematous
spaces are not bounded by any visible wall
a) Centrilobular Emphysema :
-It is predominantly located in the upper zones of
each lobe (i.e. apical and posterior segments of
the upper lobes and superior segment of the
lower lobes) has a patchy distribution
-It appears as focal lucencies (emphysematous
spaces) which measure up to 1cm in diameter
located centrally within the secondary pulmonary
lobule often with a central or peripheral dot
representing the central bronchovascular bundle

136. b) Panlobular Emphysema :
-Predominantly located in the lower lobes ,
has a uniform distribution across parts of
the secondary pulmonary lobule which are
homogeneously reduced in attenuation

138. c) Paraseptal Emphysema :
-Located adjacent to the pleura and septal lines
with a peripheral distribution within
the secondary pulmonary lobule , the affected
lobules are almost always sub-pleural and
demonstrate small focal lucencies up to 10mm
in size
-Any larger than 10mm and they should be
referred to as subpleural blebs or subpleural
bullae

140. Bullous Emphysema

141. Emphysema with pneumothorax

142. Emphysema with superimposed infection

143. d) Differential Diagnosis :
-Cystic lung disease , all have visible walls
1-Lymphangiomyomatosis (LAM)
2-Pulmonary Langerhans cell histiocytosis
(LCH)
3-Honeycomb lung : usually reduced lung
volumes

144. 3-Bronchial Asthma :
a) Pathology
b) Radiographic Features

145. a) Pathology :
-Hyperirritability of airways causes
reversible airway obstruction (bronchial
smooth muscle contraction , mucosal
edema , hypersecretion of bronchial
secretory cells : bronchospasm)
-The etiology is unknown (IgE participation)

146. b) Radiographic Features :
1-Plain Radiography
2-CT

147. 1-Plain Radiography :
-Plain films can be normal in upto 75% of
patients with asthma
-Severe or chronic asthma :
Air trapping , hyperinflation : flattened
diaphragm , increased retrosternal
airspace

149. Gloved finger sign , finger like projections from hilum from
bronchial mucoid impaction in allergic bronchopulmonary
aspergillosis or asthma

150. 2-CT :
-CT is usually used to detect the presence
of complicated associated conditions such
as allergic bronchopulmonary aspergillosis
and not to directly diagnose asthma
-Bronchial wall thickening , tramlines (also
seen in chronic bronchitis , cystic fibrosis ,
bronchiectasis & pulmonary edema)

151. Mild bronchial thickening and dilatation

152. Central bronchiectasis , a hallmark of allergic bronchopulmonary
aspergillosis (right arrow) and the peripheral tree-in-bud appearance
of centrilobular opacities (left arrow) which represent mucoid
impaction of the small bronchioles

153. 4-Bronchiectasis :
a) Pathology
b) Clinical Picture
c) Radiographic Features
d) Differential Diagnosis

154. a) Pathology :
-Refers to irreversible abnormal dilatation of the
bronchial tree
-Types :
1-Cylindrical bronchiectasis :
-Bronchi have a uniform caliber , do not taper and
have parallel walls (tram track sign when viewed
in a sagittal section and signet ring sign when
viewed in a coronal section)
-Commonest form

155. 2-Varicose bronchiectasis :
-Beaded appearances where dilated bronchi have
interspersed sites of relative narrowing
-Uncommon
3-Cystic bronchiectasis : More in lower lobes
-Severe form with cyst-like bronchi that extend to the
pleural surface , air-fluid levels are commonly present
4-Traction bronchiectasis :
-Bronchiectasis which result from the traction of fibrotic
lung surrounding an airway

158. Cylindrical bronchiectasis

159. Cylindrical Bronchiectasis

160. Varicose bronchiectasis

161. Cystic bronchiectasis

162. Cystic bronchiectasis

163. Traction bronchiectasis

164. b) Clinical Picture :
-Bronchiectasis typically presents with
recurrent chest infections , production of
copious amounts of sputum
and hemoptysis
-Hemoptysis is often the only symptom and
is encountered in up to 50% of case

165. c) Radiographic Features :
1-Plain Radiography
2-CT

166. 1-Plain Radiography :
-Tram-track opacities (horizontal , parallel
lines corresponding to thickened , dilated
bronchi) are seen in cylindrical
bronchiectasis
-Air-fluid levels may be seen in cystic
bronchiectasis
-Bronchial wall thickening (best seen end-
on)
-Increase in bronchovascular markings

169. Thin-walled, cystic structures in right lower lobe (white
arrow) , some with air-fluid levels (yellow arrows)

171. CXR (a) shows thickening of the bronchial walls and “tramlines” in the
middle and lower regions of the lungs suggestive of bronchiectasis,
confirmed on CT (b,c)

172. 2-CT :
a) Increased bronchoarterial ratio :
-Bronchi appear larger than accompanying vessels
b) Bronchial wall :
-Thickened wall (normally wall of bronchus should
be less than half the width of the accompanying
pulmonary artery branch)
-Signet ring sign , focally thickened bronchial wall
adjacent to pulmonary artery branch
-Tram track sign , tube like parallel lines
representing thickened bronchial walls

175. Signet ring

177. Tram Track sign

178. Cystic bronchiectasis with air fluid level

179. d) Differential Diagnosis :
Conditions that may mimic cystic bronchiectasis include :
1-Langerhans cell histiocytosis (LCH)
2-Lymphangiomyomatosis (LAM)
3-Lymphocytic interstitial pneumonitis (LIP)
4-Pulmonary manifestations of AIDS
5-Pneumocystis pneumonia (PCP)
6-Emphysema (To distinguish emphysema from
bronchiectasis, expiratory scans will show air trapping in
bullae while cystic bronchiectasis will collapse)
7-Cystic pulmonary metastases

180. 5-Cystic Fibrosis :
a) Pathology
b) Clinical Picture
c) Location
d) Radiographic Features
e) Differential Diagnosis

181. a) Pathology :
-Caused by an abnormality in the cystic fibrosis
transmembrane conductance regulator protein
(CFTR) which regulates the passage of ions
through membranes of mucus-producing cells
-Dysfunction of exocrine glands causing thick
tenacious mucus that accumulates and causes
bronchitis and pneumonia
-Reduced mucociliary transport : airway
obstruction with massive mucus plugging

182. b) Clinical Picture :
1-Pulmonary, 100% :
-Chronic cough
-Recurrent pulmonary infections : colonization of plugged airways by
Staphylococcus and Pseudomonas
-Progressive respiratory failure
-Finger clubbing : hypertrophic osteoarthropathy from hypoxemia
2-GI tract :
-Pancreatic insufficiency , 85% : steatorrhea , malabsorption
-Liver cirrhosis
-Rectal prolapse
-Neonates : meconium ileus, meconium peritonitis, intussusception
3-Other :
-Sinusitis : hypoplastic frontal sinus, opacification of other sinuses
-Infertility in males

183. c) Location :
-Predominantly upper lobes , superior
segments of lower lobes and central
(perihilar) distribution

184. d) Radiographic Features :
1-Plain Radiography
2-CT

185. 1-Plain Radiography :
-Chest x-rays are insensitive to the early changes of cystic
fibrosis, with changes seen on HRCT in 65% of patients
with CF and normal CXR
-Later changes include :
1-Bronchiectasis
2-Hyperinflation
3-Lobar collapse
4-Pulmonary arterial enlargement due to pulmonary arterial
hypertension is seen in patients with long standing
disease

186. CXR shows diffuse interstitial disease with bronchiectasis and nodular densities
of mucoid impaction

187. CXR shows hyperinflation and predominantly upper lobe
bronchiectasis

189. 2-CT :
a) Bronchiectasis :
*Progresses with time from cylindrical to varicose to cystic
*Severity :
-Mild: lumen equal to adjacent blood vessels
-Moderate: lumen 2 to 3 times the size of adjacent blood
vessels
-Severe : lumen >3 times the size of adjacent blood vessels
*Peribronchial wall thickening , wall thickness > the
diameter of adjacent blood vessels

190. b) Mosaic attenuation pattern :
-Due to air trapping
-Best seen on expiratory scans
c) Mucus plugging within bronchi :
-Finger in glove appearance

199. e) Differential Diagnosis :
1-Allergic bronchopulmonary aspergillosis (ABPA)
2-Tracheobronchomegaly (Mounier-Kuhn
syndrome)
3-Williams-Campbell syndrome
4-Langerhans cell histiocytosis (LCH)
5-Lymphangiomyomatosis (LAM)
6-Congenital cystic bronchiectasis

200. 6-Bronchiolitis :
a) Pathology
b) Radiographic Features
c) Swyer-James syndrome

201. a) Pathology :
-Inflammatory and fibrotic types :
a) Inflammatory Bronchiolitis :
1-Infectious :
-Acute or chronic infection (viral ,
mycoplasma & mycobacterial)
2- Hypersensitivity Penumonitis :
-Organic or inorganic inhaled agents

202. 3-Respiratory Bronchiolitis :
-Cigarette smoking
4-Follicular and Lymphocytic :
-Sjögren's syndrome , rheumatoid arthritis &
immunodeficiency
5-Panbronchiolitis :
-Idiopathic
6-Bronchiectasis :
-Cystic fibrosis & previous infection

203. b) Fibrotic (Constrictive) Bronchiolitis :
-Postinfectious , toxic fumes ,
transplantation , cryptogenic , collagen
vascular diseases & drugs

204. b) Radiographic Features :
1-Plain Radiography
2-CT

205. 1-Plain Radiography :
-Can be normal or non specific , some
associated features include :
a) Hyperinflation
b) Attenuation of vascular markings
c) Occasionally : reticular or reticulo-nodular
markings

206. Lung hyperinflation with a flattened diaphragm and bilateral atelectasis
in the right apical and left basal regions in a 16-day-old infant with
severe bronchiolitis

207. Nonspecific hyperinflation with flattening of the hemidiaphragms on
lateral CXR , as well as increased AP diameter and prominent size
of retrosternal clear space , mild bilateral symmetric perihilar
peribronchial prominence

208. 2-CT :
a) Direct Signs :
-Thickening of the bronchiolar wall by inflammatory cells
results in centrilobular nodules and V- or Y-shaped
branching linear opacities that represent the tree-in-bud
pattern
-Inflammatory cellular infiltration in the peribronchiolar
alveoli results in poorly defined centrilobular nodules that
often have an attenuation less than that of soft tissue
-Bronchiolectasis is a less common direct sign of
bronchiolitis and is found most commonly in chronic
forms of bronchiolitis , the dilated bronchioles are
identifiable close to the pleural surface

209. Multiple poorly defined centrilobular nodules, many of which connect to
branching linear structures (arrows) , tree-in-bud pattern

210. Diffuse fine poorly defined centrilobular nodules (arrows)
with more patchy ground-glass opacity posteriorly

211. Centrilobular nodules with tree-in-bud pattern (arrowheads), bronchiolectasis
(arrow), and cylindric bronchiectasis

212. b) Indirect Signs :
-Air trapping is an indirect sign of obstructive
small airways disease and may be
identified by the presence of mosaic
attenuation on inspiratory CT that is
accentuated with expiratory imaging

213. Multiple patchy areas of low attenuation in both lungs , note
mild bronchial wall thickening and cylindric
bronchiectasis

214. Expiratory high-resolution CT image shows accentuation of areas of decreased
attenuation , confirming presence of air trapping

215. c) Swyer-James Syndrome (Mcleod) :
1-Pathology
2-Radiographic Features

216. 1-Pathology :
-The late sequela of bronchiolitis in
childhood
-Is a rare lung condition that manifests
as unilateral hemithorax lucency as a
result of post-infectious obliterative
bronchiolitis
-The condition typically follows a viral
respiratory infection (adenovirus) in
infancy or childhood

217. 2-Radiographic Features :
a) Plain Radiography
b) CT

218. a) Plain Radiography :
-It is generally characterized on radiographs
by a unilateral small lung with
hyperlucency and air trapping

222. b) CT :
-CT shows the affected lung as being
hyperlucent with diminished vascularity ,
the size of the majority of the affected
lobes are smaller although occasionally
they can be normal
- Bronchiectasis may be present although
this is not a universal finding

226. c) Upper Airway Obstruction in Children :
(i) Approach
(ii) Causes of Upper Airway Obstruction

227. (i) Approach :
-Inspiratory stridor is the most common
indication for radiographic upper airway
evaluation
-Obtain 3 films :
*Lateral neck : full inspiration , neck
extended
*AP & lateral chest : full inspiration , include
upper airway

228. -Primary diagnostic considerations :
a) Congenital abnormalities (webs , malacia)
b) Infection (epiglottitis , croup , abscess)
c) Foreign body (airway or
pharyngoesophageal)
d) Masses (lymphadenopathy , neoplasms)

229. -If upper airway is normal , consider :
1-Pulmonary causes (foreign body ,
bronchiolitis)
2-Mediastinal causes (vascular rings ,
slings)
3-Congenital heart disease (CHD)

230. -Normal Appearance :
*Three anatomic regions :
1-Supraglottic region
2-Glottic region : ventricle and true cords
3-Subglottic region
*Epiglottis and aryepiglottic folds are thin
structures
*Glottic shoulders are seen on AP view
*Adenoids are visible at 3 to 6 months after birth
*Normal retropharyngeal soft tissue thickness (C1-
C4) = three-fourths vertebral body width

233. (ii) Causes of Upper Airway Obstruction :
a) Congenital Abnormalities (webs ,
malacia)
b) Infection (epiglottitis , croup , abscess)
c) Foreign Body (airway or
pharyngoesophageal)
d) Masses (lymphadenopathy , neoplasms)

234. a) Congenital Abnormalities :
1-Laryngomalacia
2-Tracheomalacia
3-Webs
4-Tracheal Stenosis
5-Subglottic Stenosis
6-Choanal Atresia

235. 1-Laryngomalacia :
-Common cause of stridor in the 1st year of
life and usually resolves by 2 years
-Immature laryngeal cartilage leads to
supraglottic collapse during inspiration
-Diagnosis is established by fluoroscopy
(laryngeal collapse with inspiration)

236. 2-Tracheomalacia :
-Weakness of tracheal wall which may be primary or
secondary :
a) Primary :
-Premature infants
-Cartilage disorders (polychondritis , chondromalacia &
MPS)
b) Secondary :
-Following prolonged intubation
-With TOF / osophageal atresia
-With vascular ring or other extrinsic vascular compression
-With long standing external compression by tumor

237. 3-Webs :
-Most common in larynx
4-Tracheal Stenosis :
-Diffuse hypoplasia , 30%
-Focal ringlike stenosis , 50%
-Funnel-like stenosis , 20%

239. 5-Subglottic Stenosis :
-Fixed narrowing at level of cricoid
-Failure of laryngeal recanalization in utero
6-Choanal Atresia :
-Most common congenital nasal abnormality
-Bilateral in 33 % or unilateral (R>L)
-Bony (90 %) or membranous , complete or incomplete
-Diagnosis is done by failure to pass a catheter through the
nose

240. b) Infection :
1-Epiglottitis
2-Croup
3-Retropharyngeal Abscess
4-Edema
5-Retropharyngeal Hemorrhage

241. 1-Epiglottitis :
a) Incidence
b) Clinical Picture
c) Radiographic Features
d) Differential Diagnosis

242. a) Incidence :
-Life threatening bacterial infection of the
upper airway
-Most commonly caused by Haemophilus
influenzae
-Age : 3 to 6 years

243. b) Clinical Picture :
-Fever
-Dysphagia
-Drooling
-Sore throat

244. c) Radiographic Features :
-Key radiographic view : lateral neck
-Thickened epiglottis
-Thickened aryepiglottic folds (hallmark)
-Subglottic narrowing due to edema , 25% :
indistinguishable from croup on AP view
-Distention of hypopharynx

246. d) Differential Diagnosis :
-Other causes of enlarged epiglottis or
aryepiglottic folds :
1-Caustic ingestion
2-Hereditary angioneurotic edema
3-Omega-shaped epiglottis (normal variant
with normal aryepiglottic folds)
4-Stevens-Johnson syndrome

247. 2-Croup :
a) Incidence
b) Clinical Picture
c) Radiographic Features

248. a) Incidence :
-Age : 6 months to 3 years (younger age
group than epiglottitis)
-Most commonly caused by parainfluenza
virus
-Subglottic laryngotracheobronchitis

249. b) Clinical Picture :
-Barking cough
-Upper respiratory tract infection
-Self limited

251. c) Radiographic Features :
-Key view : AP view
-Subglottic narrowing (inverted “V” or
“steeple sign”)
-Steeple sign : loss of subglottic shoulders
-Lateral view should be obtained to exclude
epiglottitis

253. 3-Retropharyngeal Abscess :
a) Incidence
b) Clinical Picture
c) Radiographic Features
d) Differential Diagnosis

254. a) Incidence :
-Typically due to extension of a suppurative
bacterial lymphadenitis , most commonly
S. aureus , group B streptococci , oral
flora
-Age : <1 year
-Other causes include foreign body
perforation and trauma

255. b) Clinical Picture :
-Fever
-Stiff neck
-Dysphagia
-Stridor (uncommon)
-Most cases present as cellulitis rather than
true abscess

256. c) Radiographic Features :
-Widened retropharyngeal space (most
common finding)
-Air in soft tissues is specific for abscess
-May contain air fluid level
-Straightened cervical lordosis
-CT : rim enhancement

257. d) Differential Diagnosis :
-Retropharyngeal hematoma
-Neoplasm (i.e. rhabdomyosarcoma)
-Lymphadenopathy

258. 4-Edema : (Laryngeal)
-Caused by :
a) Angioedema (allergic , anaphylactic or
hereditary)
b) Inhalation of noxious gases
c) Trauma

259. 5-Retropharyngeal Hemorrhage :
-Due to :
1-Trauma
2-Neck surgery
3-Direct carotid arteriography
4-Bleeding disorders
-Widening of the retropharyngeal soft tissue
space

260. c) Foreign Body :
1-Incidence
2-Location
3-Radiographic Features

261. 1-Incidence :
-Common cause of respiratory distress
-Age : 6 months to 4 years
2-Location :
-right bronchi > left bronchi > larynx ,
trachea

262. 3-Radiographic Features :
a) Bronchial foreign body :
-Unilateral air trapping causing hyperlucent
lung , 90%
-Only 10% of foreign bodies are radiopaque
-Expiratory film or lateral decubitus makes
air trapping more apparent

264. b) Tracheal foreign body :
-CXR is usually normal
-Foreign body usually lodges in sagittal
plane

265. d) Masses :
1-Grossly Enlarged Tonsils & Adenoids
2-Nasal Angiofibroma
3-Antrochoanal Polyp
4-Subglottic Hemangioma
5-Respiratory Paplillomatosis
6-External Compression

266. 1-Grossly Enlarged Tonsils & Adenoids :
a) Incidence
b) Radiographic Features

267. a) Incidence :
-The tonsils consist of lymphoid tissue that
encircles the pharynx
-Three groups : pharyngeal tonsil (adenoids) ,
palatine tonsil and lingual tonsil
-Tonsils enlarge secondary to infection and may
obstruct nasopharynx and/or eustachian tubes
-Rarely , bacterial pharyngitis can lead to a
tonsillar abscess (quinsy abscess), which
requires drainage

268. -Specific causes include :
1-Mononucleosis (Epstein-Barr virus)
2-Coxsackievirus (herpangina , hand-foot-
mouth disease)
3-Adenovirus (pharyngoconjunctival fever)
4-Measles prodrome (rubeola)
5-β-Hemolytic Streptococcus (quinsy
abscess)

269. b) Radiographic Features :
-Mass in posterior nasopharynx (enlarged
adenoids)
-Mass near end of uvula (palatine tonsils)
-CT is useful to determine the presence of a
tonsillar abscess

270. 2-Nasal Angiofibroma
3-Antrochoanal Polyp
4-Subglottic Hemangioma :
-The most common subglottic soft tissue mass in
infancy
-Occurs before 6 months of age
-Produces asymmetrical narrowing of the
subglottic airway

271. 5-Respiratory Paplillomatosis :
-Occur anywhere from the nose to the lungs
-Irregular soft tissue masses which may
cavitate around the glottis or in the trachea
6-External Compression :
-From Other Mediastinal Structures
(lymphadenopathy)