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1. ASTHMA
Dr. SEMATIMBA HENRY
MMED/RAD ECUREI

2. ASTHMA
• Asthma is a chronic inflammatory disorder of the airways associated with an
exaggerated bronchoconstrictor response to a wide variety of stimuli, resulting in
recurrent episodes of dyspnea and wheezing.
• Inciting causes: environmental allergens, viral infections, exercise, analgesics, air
pollution, weather changes, cigarette smoke, occupational sensitizing agents, and
irritants such as household sprays and paint fumes.
• The most important inciting cause is indoor allergens (house dust).
• Pathologic features include thickening of the airway walls by a combination of
edema and an increase in smooth muscle and in the size of the mucous glands.

3. Radiography findings
• The most common radiographic abnormalities in patients who have asthma are
hyperinflation and bronchial wall thickening (Figs. 74-3 and 74-4);
• less frequent manifestations are prominence of the hila, increased central lung
markings, and peripheral oligemia (Figs. 74-5 and 74-6).
• The prevalence of these abnormalities is influenced by several factors, including
the age at onset and severity of asthma and the presence of other diseases or
complications of asthma.
• In the presence of acute severe asthma or during a prolonged, intractable attack,
the most characteristic radiographic signs are pulmonary hyperinflation and
expiratory air trapping.

4. Radiography findings
• Pulmonary hyperinflation is manifested as an increase in the depth of the
retrosternal space, an increase in lung height, and flattening of the diaphragm.
• Thickening of the airways occurs in both segmental and subsegmental bronchi and
can be seen either as ring shadows viewed end-on or as “tram-line” opacities
viewed en face.
• Prominence of the main pulmonary artery and its hilar branches with rapid tapering
is indicative of transient precapillary pulmonary arterial hypertension secondary to
hypoxia.
• Additional vascular findings include diffuse narrowing and blood flow
redistribution into the upper lobes (the latter in the absence of other signs of
postcapillary hypertension) and a paucity of vessels in the outer 2 to 4 cm of the
lungs

5. Radiographic manifestations of acute asthma. A, Posteroanterior chest radiograph shows
increased lung volumes and reduction of the peripheral vascular markings. B, Lateral view
demonstrates increased retrosternal airspace.

6. Radiographic manifestations of asthma. A detail view
of the right lung from a frontal radiograph shows
bronchial wall thickening (arrowhead).
Pneumomediastinum in acute asthma.
Posteroanterior chest radiograph in a 21-year-old man
with acute asthma demonstrates hyperinflation and
pneumomediastinum (arrows).

7. Peripheral oligemia in acute asthma. A, A detail view of the left lung from a posteroanterior chest
radiograph of a young man during an episode of acute bronchospasm reveals moderate hyperinflation. The
vasculature in the outer 2 to 3 cm of lung is inconspicuous and barely visible, thus creating a subpleural
shell of oligemic lung. B, A repeated study 1 year later during remission shows less hyperinflation; the
pulmonary vessels now taper normally, and most are visible well into the lung periphery.

8. Radiography findings
Reversible precapillary pulmonary
hypertension in acute asthma. A detail view of
the heart and left hilum from a
posteroanterior radiograph
(A) reveals enlargement of the main
pulmonary artery (arrowheads) and left
interlobar artery (arrow), consistent with
the presence of pulmonary arterial
hypertension. At the time of this study, the
patient, a young man, was experiencing a
severe attack of acute bronchospasm.
Approximately 2 years later during a period
of remission, a repeated radiograph
(B) (B) demonstrates a return to normal
configuration of the main and
interlobar arteries. Note that the heart has
increased in size during this interval,
reflecting a decrease in the high
transpulmonary pressure that existed
during the acute attack and the
consequent reduction in venous return

9. Radiography findings
• Despite the observations just outlined, the chest radiograph has a limited role in
the diagnosis of asthma.
• It is often normal, even during an acute attack; moreover, when it is abnormal, the
findings are nonspecific.
• The two main indications for chest radiography are to exclude other conditions
that cause wheezing (particularly emphysema, left-sided heart failure, and
obstruction of the trachea or major bronchi by tumor or foreign body) and to
identify complications.
• Complications of asthma include pneumonia, atelectasis, pneumomediastinum,

10. Computed Tomography (Multidetector, High-Resolution)
High-resolution CT findings include:
• thickening and narrowing of the bronchi,
• bronchial dilatation patchy areas of decreased attenuation and vascularity, and
• air trapping.
• The bronchial wall thickening and luminal narrowing reflect the presence of
bronchial wall edema and the increase in smooth muscle and in the size of the
mucous glands
• The bronchial abnormalities seen on CT can be quantified subjectively and
objectively and have been shown to increase with increasing severity of disease.

11. Bronchial wall thickening in chronic asthma. A, High-resolution CT at the level of the lower lobes shows
several bronchi with thickened walls (straight arrows). Also noted are several normal-appearing bronchi (curved
arrows). B, Coronal reformatted image shows bronchial wall thickening (straight arrows) in the middle and upper
lung zones. The patient was a 67-year-old man who was a nonsmoker with chronic asthma.

12. Asthma: CT findings
• Although the majority of bronchi of patients with asthma have normal or
decreased internal diameter, approximately 30% to 40% of adult patients with
uncomplicated asthma have one or more bronchi that are dilated.
• The bronchiectasis seen in patients with uncomplicated asthma typically is
cylindrical, and the bronchoarterial ratio is usually less than 1.5.
• Follow-up studies suggest that the bronchial dilatation seen in asthmatic patients
is not reversible.

13. Asthma: CT findings
Bronchiectasis in chronic asthma. High-resolution CT at the level of the lower lobes shows left
lower lobe bronchiectasis (arrows), areas of decreased attenuation and vascularity in the left
lower lobe, and volume loss. The patient was a 56-year-old woman with chronic asthma.

14. Asthma: CT findings
• High-resolution CT manifestations of bronchiolar abnormalities in
patients with asthma include:
• areas of decreased attenuation and vascularity,
• air trapping, and
• small centrilobular opacities.
• Areas of decreased attenuation and vascularity are seen on high-
resolution CT scans performed at end-inspiration in approximately
20% of patients with asthma.

15. Mosaic attenuation and perfusion pattern in asthma. A, High-resolution CT performed at end inspiration
shows extensive bilateral areas of decreased attenuation and vascularity with blood flow redistribution to
normal lung, resulting in a mosaic attenuation and perfusion pattern. B, High-resolution CT performed
after maximal expiration demonstrates extensive air trapping. The patient was a 54-yearold woman with
severe chronic asthma.

16. Asthma: CT findings
• A more common finding is the presence of air trapping on high-resolution CT
images obtained after maximal expiration.
• Although the extent of air trapping increases during an acute attack, air trapping is
also often present in stable patients.
• This presumably reflects the presence of chronic inflammation and muscle
hypertrophy of the small airways or, in some patients, development of obliterative
bronchiolitis.
• Prominent centrilobular structures or small centrilobular opacities have been
reported in 10% to 20% of patients with asthma.
• These presumably reflect the presence of mucus stasis in bronchioles or peribronchiolar
inflammation

17. Air trapping in asthma. A, High-resolution CT performed at end inspiration shows subtle areas of
decreased attenuation and vascularity. B, High-resolution CT performed after maximal expiration
demonstrates extensive air trapping. The patient was a 62-year-old man with asthma and cough at
the time of the CT.

18. A, High-resolution CT image demonstrates extensive areas of decreased attenuation and vascularity
consistent with obliterative (constrictive) bronchiolitis and a few small nodular opacities in the
peripheral regions of the lower lobes. B, Maximum intensity projection image better demonstrates
that the peripheral nodular opacities have a centrilobular distribution (arrows). The centrilobular
nodules presumably refl ect the presence of mucostasis or peribronchiolar inflammation.

19. Asthma: CT findings
• Parenchymal abnormalities in asthma include:
• hyperinflation,
• emphysema, and
• occasionally cystic spaces.
• Emphysema is uncommon in asthmatic nonsmokers; when it is present, it is
usually mild and secondary to cicatricial peribronchiolar fibrosis.
• Rarely, cystic changes may result from over inflation distal to chronic
inflammatory bronchiolitis.

20. Cysts in chronic asthma. High resolution CT shows bilateral thin-walled cysts (arrows) and
localized areas of decreased attenuation and vascularity. The patient was a 63-year-old woman
with chronic asthma who was a nonsmoker.

21. Asthma: CT findings
• A relatively common complication seen on high resolution CT in asthmatic
patients is the presence of mucoid impaction.
• This finding should raise the possibility of allergic bronchopulmonary
aspergillosis, a condition characterized by hypersensitivity reaction to
endobronchial growth of Aspergillus fumigatus.
• The high resolution manifestations of allergic bronchopulmonary aspergillosis
include:
• homogeneous tubular,
• Centrilobular nodules
• finger in glove, or branching endobronchial opacities and
• bronchiectasis involving mainly the segmental and subsegmental bronchi of the upper lobes

22. Allergic bronchopulmonary aspergillosis. A, High-resolution CT image of the left upper lobe
shows branching opacities characteristic of mucoid impaction. B, High-resolution CT image at a
slightly higher level demonstrates mucoid impaction in several small bronchi. The patient was a
73-year-old woman with asthma and allergic bronchopulmonary aspergillosis.

23. Asthma: CT findings
• In approximately 30% of cases, the impacted mucus has increased attenuation,
consistent with calcification.
• The mucus plugging can extend into bronchioles, resulting in centrilobular
nodular opacities.
• Obstructive atelectasis may also be seen but is uncommon.
• Other complications that are seen with increased prevalence in asthmatic patients,
such as chronic eosinophilic pneumonia and Churg-Strauss syndrome

24. Allergic bronchopulmonary aspergillosis. A, High-resolution CT image shows right lower lobe
atelectasis and centrilobular nodules (arrows). B, CT image photographed at soft tissue window
demonstrates high-attenuation tubular opacities consistent with mucoid impaction (arrowheads)

25. Allergic bronchopulmonary aspergillosis. A, High-resolution CT image shows extensive
varicose bronchiectasis in the upper lobes. B, Coronal reformatted image demonstrates the
upper lobe and central distribution of the bronchiectasis. The patient was a 32-year-old
woman with chronic asthma and allergic bronchopulmonary aspergillosis.

26. Asthma: CT findings
• CT plays a limited role in the diagnosis and management of patients with asthma
and is seldom indicated during an acute attack.
• The main role of CT is in the assessment of tracheal and bronchial abnormalities
that may mimic asthma and in the assessment of complications such as allergic
bronchopulmonary aspergillosis.
• CT of value in the diagnosis of endotracheal and endobronchial tumors that may
mimic asthma clinically and that may be difficult to visualize on the radiograph is
well known.
• CT also can play a major role in distinguishing asthma from
tracheobronchomalacia, a condition that is being recognized with increasing
frequency as a potential mimic of asthma.

27. Asthma: CT findings
Endobronchial carcinoid tumor in
patient who presented with history of
asthma.
• A, Inspiratory high-resolution CT
image shows endoluminal tumor in
right main bronchus. Note decreased
size of right lung and diffuse decrease
in attenuation and vascularity
compared with the left lung.
• B, Expiratory CT image demonstrates
marked air trapping. The patient was
a 31-year-old woman with atypical
carcinoid tumor.
• She presented with recurrent episodes
of shortness of breath and tightness in
the chest and had a clinical diagnosis
of asthma.

28. Tracheobronchomalacia
• Tracheobronchomalacia is a proximal airway disease characterized by expiratory
airway obstruction due to collapse of the trachea and central bronchi caused by the
positive intrapleural pressure
• Diagnosis can be made at bronchoscopy, expiratory CT, or, preferably, dynamic
expiratory CT.
• The diagnosis of tracheobronchomalacia is based on a greater than 50% narrowing
on expiratory CT .
• Tracheobronchomalacia may be missed if images are obtained during a
suboptimal expiratory effort.
• Adequate expiratory effort can be assessed on CT by the presence of anterior
bowing of the posterior tracheal membrane.

29. Bronchomalacia. A, Inspiratory high-resolution CT image is normal. B, Expiratory CT
demonstrates air trapping and greater than 50% decrease in bronchial diameters consistent
with bronchomalacia. The patient was a 64-year-old woman in whom asthma-like symptoms of
wheezing and shortness of breath were shown to be due to bronchomalacia

30. COPD

31. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)
• COPD is a slowly progressive airway obstructive disorder resulting from an
exaggerated inflammatory response to cigarette smoke or other inhaled pollutants
• These ultimately destroy lung parenchyma (emphysema) and induce irreversible
reduction of the calibre of the small airways (obstructive bronchiolitis).
• Both lesions may be associated in the same patient.
• On the other hand, narrowing and loss of terminal bronchioles clearly precede the
appearance of microscopic emphysematous destruction.

32. COPD
• The use of CT in evaluation of patients with COPD has made it clear that
individuals with identical severity of airflow obstruction exhibit different
morphological appearances.
• Some have extensive emphysema while others have only a little emphysema,
suggesting more significant small airway disease.
• These differences in morphological appearances may be related to differences in
pathophysiology and genomic profile

33. Inflammatory Changes in the Airways in COPD
• Inflammatory changes in the airways in COPD patients involve both small
airways and large airways.
• Small airway disease in COPD is initially characterised by inflammatory change
in the walls and around the respiratory bronchioles.
• In more advanced disease, inflammatory changes in respiratory bronchioles are
associated or replaced by obstruction of the lumen of the small airways with plugs
of inflammatory exudates and mucus.
• In even more advanced involvement, the lumen of the terminal bronchioles are
narrowed by peribronchiolar fibrosis (obstructive bronchiolitis).
• Large airway disease in COPD includes inflammation and remodelling of the
trachea and bronchi.

34. Emphysema
• Emphysema is defined as a condition of the lung characterised by permanent,
abnormal enlargement of airspaces distal to the terminal bronchiole, accompanied
by the destruction of their walls without obvious fibrosis.
• The most important factor by far is cigarette smoking.
• There is also a causal relationship between HIV infection and the development of
early emphysema.

35. Emphysema
• Emphysema is thought to result from the destruction of elastic fibres
caused by an imbalance between proteases and protease inhibitors in
the lung and from the mechanical stresses of ventilation and coughing.
• As emphysema develops, lung destruction progresses, airspaces
enlarge, and elastic recoil declines, reducing radial traction on
bronchial walls and on blood vessels and allowing airways and vessels
to collapse.

36. Emphysema
• Emphysema is traditionally based on the microscopic region of disease within the
secondary pulmonary lobule.
• The principal types are centrilobular, panlobular, paraseptal and irregular
emphysema.
• Centrilobular (centriacinar) emphysema affects mainly the proximal respiratory
bronchioles and alveoli in the central part of the acinus.
• The process tends to be most developed in upper parts of the lungs.
• It is strongly associated with cigarette smoking.
• Inflammatory changes in the small airways are common with plugging, mural
infiltration and fibrosis leading to stenosis, distortion and destruction

37. Emphysema
• Paraseptal emphysema selectively involves the alveoli adjacent to
connective tissues septa and bronchovascular bundles, particularly at
the margins of the acinus and lobule but also subpleurally and adjacent
to the bronchovascular bundles.
• Airspaces in paraseptal emphysema may become confluent and
develop into bullae, which may be large.
• Airway obstruction and physiological disturbance may be minor.

38. Emphysema
• Panlobular (panacinar) emphysema is characterized by a dilatation of the
airspaces of the entire acinus and lobule.
• With progressive destruction, all that eventually remains are thin strands of
deranged tissue surrounding blood vessels.
• It is the most widespread and severe type of emphysema.
• Pathological changes are distributed throughout the lungs, but they are often
basely predominant.
• Panlobular emphysema is the type occurring in α1-antitrypsin deficiency and in
familial cases.

39. Emphysema
• Irregular emphysema is referred to as para-cicatricial emphysema or
irregular airspace enlargement, and occurs in patients with pulmonary
fibrosis.
• It is commonly seen adjacent to localised parenchymal scars, diffuse
pulmonary fibrosis, and in the pneumoconiosis, particularly
progressive massive fibrosis.

40. Emphysema
Radiographic Findings
• Chest radiography may be normal.
• When radiographic abnormalities are present, they can include:
• hyperinflation,
• oligaemia,
• bronchial wall thickening
• accentuation of linear lung markings.
• Thickening of the bronchial walls leads to tubular and ring shadows.
• Increased lung markings cause the appearance of ‘dirty chest’, a term widely used
for describing a loss in clarity of the lung vessels

41. Emphysema
Chronic bronchitis and obstructive lung disease. Postero-anterior chest radiograph shows
mild overinflation. A ring shadow is visible above the left hilum (arrow), reflecting bronchial wall
thickening. There is also an accentuation of linear markings in the right lung basis.

42. Emphysema
• Sabre-sheath trachea may be present.
• Cor pulmonale is a recognised complication which is seen most exclusively in
hypoxic patients.
• With the onset of heart failure, the heart and hila and intermediate lung vessels
become enlarged.
• Enlargement of vessels is present in all zones and affects particularly segmental
vessels and a few divisions beyond.
• Signs of overinflation are the best predictors of the presence and severity of
emphysema.

43. Emphysema
Signs of overinflation include:
• The height of the right lung being greater than 29.9 cm,
• Location of the right hemidiaphragm at or below the anterior aspect of the seventh
rib,
• Flattening of the hemidiaphragm,
• Enlargement of the retrosternal space,
• Widening of the sternodiaphragmatic angle,
• Narrowing of the transverse cardiac diameter.

44. Emphysema
Alterations in lung vessels include:
• arterial depletion, whereas vessels of normal, or occasionally
increased, calibre are present in unaffected areas of the lung,
• absence or displacement of vessels caused by bullae,
• widened branching angles with loss of side branches and vascular
redistribution.

45. Emphysema
• With the development of cor pulmonale, or left heart failure,
the radiographic appearances will alter and may become less
obviously abnormal.
• The heart may then appear to be normal in size, or sometimes enlarged,
• The diaphragm becomes less flat and the pulmonary vessels less attenuated.
• Bullae may be as small as 1 cm in diameter or may occupy the whole
hemithorax, causing marked relaxation collapse of the adjacent lung.

46. Emphysema
Severe diffuse emphysema.
PA (A) and lateral (B) chest
radiographs. The diaphragm is
displaced downwards, and appears
flattened. On the PA radiograph (A),
the transverse cardiac diameter is
reduced. The diaphragm appears
irregular in contours due to an
abnormal visibility of diaphragmatic
insertions on the ribs.
Note the depression of vessels in the
periphery of the lungs. On the lateral
radiograph (B), there is a widening of
the sternodiaphragm angle and an
increase of dimensions of the
retrosternal transradiant area.

47. Emphysema
• Bullae caused by paraseptal emphysema are much more common in the
upper zones, but when they are associated with widespread panlobular
emphysema, the distribution is much more even.
• Occasionally the wall is completely absent and in such a case bullae can be
difficult to detect.
• The presence of emphysema associated with large bullae is referred to as bullous
emphysema.

48. Emphysema
Giant bullous emphysema. The PA chest radiograph shows large avascular transradiant areas
in the upper and lower parts of the right lung. The bullae are marginated with
thin curvilinear opacities.

49. Emphysema
• An entity mainly seen in young men, characterised by the presence
of large progressive upper lobe bullae which occupy a significant volume of a
hemithorax and are often asymmetrical, is referred as giant bullous emphysema,
vanishing lung syndrome or primary bullous disease of the lung.
• Large bullae may be seen as avascular transradiant areas usually
separated from the remaining lung parenchyma by a thin curvilinear wall.
• They can cause marked relaxation collapse of the adjacent lung and can even
extend across into the opposite hemithorax, particularly by way of the anterior
junction area.
• Spontaneous pneumothorax commonly occurs in association with localised areas
of emphysema or bullae affecting the lung apices.

50. Emphysema
• Bullae may enlarge progressively over months or years; a period of stability may
be followed by a sudden expansion.
• Bullae may also disappear, either spontaneously or following infection or
haemorrhage.
• The main complications of bullae include pneumothorax, infection and
haemorrhage.
• In case of infection or haemorrhage, bullae contain fluid and develop an air–fluid
level.

51. Emphysema
• When a bulla becomes infected the hairline wall becomes thickened
and may mimic a lung abscess.
• Carcinoma arising in or adjacent to bullae should be suspected in case
of:
• mural nodule,
• mural thickening,
• a change in diameter of the bulla,
• pneumothorax
• accumulation of fluid within the bulla

52. CT Findings: Small Airway Disease
• At the earlier stage of the disease, the inflammatory changes in the small airways
are seen on CT as multiple areas of ground-glass attenuation and small
centrilobular ill-defined nodular opacities.
• These abnormalities, predominant in the upper lobes or sometimes more diffuse in
distribution, have been reported to be present in about 22–25% of asymptomatic
smokers.
• At the later stage of the disease, the CT findings include mosaic perfusion pattern
(low attenuation and low perfusion areas where the terminal bronchioles are
obstructed) and expiratory air trapping in the same areas.

53. Respiratory bronchiolitis in heavy smoker. Axial CT at the level of the upper lobes. Centrilobular ill-
defined small nodular opacities distributed in the periphery of the upper lobes on a background of ground-
glass opacities. Some small centrilobular and paraseptal emphysematous spaces are also present.

54. COPD patient with airway disease predominant phenotype. Axial CT at the levels of the upper (A) and
lower (B) parts of the chest. Few small centrilobular and paraseptal emphysematous spaces in the upper
lobes. Bronchial wall thickening, slight bronchial dilatation and lung parenchyma hypoattenuation reflecting
obstructive bronchiolitis in the lower lobes.

55. Emphysema
• CT is the most accurate imaging technique to detect emphysema in vivo and to
determine morphological type and extent.
• Emphysema is characterised by the presence of areas of abnormally low
attenuation which can be easily contrasted with surrounding normal lung
parenchyma if sufficiently low window values (–800 to –1000 HU) are used.
• Focal areas of emphysema usually lack distinct walls as opposed to lung cysts.
• In many patients, it is possible to classify the type of emphysema on the basis of
its CT appearance, although the different types, as well as bullae, may be present
in association in the same patient.

56. Centrilobular Emphysema (CLE).
• Centrilobular emphysema is recognised on CT by the presence of small well or
poorly defined local lucencies surrounded by normal lung.
• Small vessels, often seen traversing the hypoattenuated areas, are centrilobular
pulmonary arteries or arterioles, marking the centre of each lobule.
• However, the pulmonary arteries appear normal in calibre.
• This pattern of emphysema correlates well with pathologically demonstrated
centrilobular emphysema.
• This is the commonest type of smoking-related emphysema, and is usually upper
lung predominant.

57. Centrilobular Emphysema (CLE).
HRCT targeted on the right lung shows multiple small round areas of low attenuation
distributed through the lungs, mainly around the centrilobular arteries.

58. Centrilobular Emphysema (CLE).
• Although the centrilobular location of the lucencies cannot always be recognised
on CT, the presence of multiple small areas of emphysema scattered throughout
the lung is diagnostic of centrilobular emphysema.
• As the emphysema becomes more severe, the areas of low attenuation become
larger and coalescent, making the centrilobular distribution of emphysema less
apparent.
• Large areas of CLE may be distinguished from panlobular emphysema by the
presence of a preserved rim of normal lung attenuation intervening between areas
of lung destruction.

59. Centrilobular Emphysema (CLE).
• In most cases the areas of low attenuation have no visible walls;
however, very thin walls may be seen, particularly when the areas of
emphysema are extensive.
• The apparent walls in such cases probably represent atelectasis or
interlobular septa adjacent to the emphysematous spaces.
• When the extent of emphysema increases, the distribution of low-
attenuation areas may appear diffuse without predominance.

60. Advanced centrilobular emphysema in a smoker.
Axial CT at the level of the upper lobes shows large and coalescent areas of low attenuation with lobular
margins corresponding to advanced centrilobular emphysematous spaces predominantly distributed on
the right side. The patient had a history of left upper lobectomy for bronchopulmonary carcinoma. Note
the thickened bronchi related to associated airway remodelling (arrow).

62. Centrilobular emphysema: classic CT findings. CT
image targeted to the right lung shows well-defi ned “holes”
in the centrilobular portions of the secondary pulmonary
lobule surrounding small vessels. Note the lack of visible
walls. The findings are typical of centrilobular emphysema.
Centrilobular emphysema: coronal reconstruction.
Coronal reformatted CT image shows apical predominance of
emphysematous lesions.

63. Mild centrilobular emphysema. High-resolution CT
section through the left upper lobe shows subtle small
areas of hypoattenuation corresponding to
centrilobular emphysema. The lesions have no walls
and are directly adjacent to normal lung parenchyma.
Mild centrilobular emphysema. High-resolution
CT section through the left upper lobe shows subtle small
areas of hypoattenuation corresponding to centrilobular
emphysema. Hypoattenuation is located next to the central
core structures of the secondary pulmonary lobule.

64. Advanced centrilobular emphysema. High-resolution CT
section through the left upper lobe shows obvious areas
of hypoattenuation corresponding to advanced
centrilobular emphysema. Although most secondary
pulmonary lobules are occupied by emphysema, the
structure of the lobule is not destroyed.
Moderate centrilobular emphysema: coronal
reconstruction of high-resolution CT image of the left
lung. Although emphysematous lesions can be seen in
the entire lung, emphysema predominates in the upper
lobe and the uppermost parts of the lower
lobe.

65. Panlobular or Panacinar Emphysema (PLE).
• Panlobular or panacinar emphysema is manifested as a generalised decrease of
attenuation of the lung parenchyma without focal lucencies.
• Although this pattern is classically described with α1-antitryspin deficiency, a
similar pattern may be seen with severe smoking-related emphysema.
• The vessels in the affected lung are usually reduced in number and in calibre,
straightened and show decreased branching.
• The appearance of featureless decreased attenuation may sometimes be quite
difficult to distinguish from severe obliterative bronchiolitis.

66. Panlobular or Panacinar Emphysema (PLE).
• The presence of long lines in the lower lobes reflecting fibrosis within the
remaining interlobular septa in panlobular emphysema helps distinguish this
entity from obliterative bronchiolitis.
• Usually these abnormalities are most severe in the lower lobes.
• As clinical manifestations of PLE associated with α1-protease inhibitor deficiency
are often seen in cigarette smokers, focal lucencies due to centrilobular
emphysema may be seen in the upper lobes.

67. Panlobular emphysema in a patient with α1- antitryspin deficiency. Axial CT at the levels of the mild (A)
and lower parts (B) of the lung with diffuse lung attenuation and paucity of the pulmonary vessels. The presence
of multiple thin lines, particularly throughout the lung bases, reflects a distortion of the anatomical structure of
the lung parenchyma and thickening of the remaining interlobular septa by lung fibrosis.

68. Panlobular or Panacinar Emphysema (PLE)
• Occasionally, PLE occurring in smokers is predominant in the upper
lungs.
• Paraseptal emphysema and bullae can also be seen, but are not a major
feature of the disease.
• In severe PLE, the characteristic appearance of extensive lung
destruction and the associated paucity of vascular markings may have
a diffuse distribution.
• On the other hand, mild and even moderately severe PLE can be
very subtle and difficult to detect radiologically

69. Moderate panlobular emphysema. High-resolution
CT section through the left upper lobe shows areas of
hypoattenuation with effacement of lung structure.
Structures suggestive of secondary pulmonary lobules
can barely be detected.
Advanced panlobular emphysema. High-resolution
CT section through the right upper lobe shows that
in the ventral parts of the lung, lung structure is
completely destroyed by emphysema.

70. Advanced panlobular emphysema. Highresolution CT
section through the right upper lobe shows extensive
emphysematous destruction. The lack of lung
structures gives the resulting areas of hypoattenuation
a relatively homogeneous appearance.
Advanced panlobular emphysema: coronal
reconstruction of high-resolution CT image of
the right lung. The areas of emphysematous
destruction occupy all parts of the lung and
show no particular predominance.

71. Paraseptal Emphysema (PSE)
• Paraseptal emphysema is characterised by subpleural and peribronchovascular
regions of low attenuation separated by intact interlobular septa thickened by
associated mild fibrosis.
• PSE has a special predilection for peripheral subpleural lobules (along the
mediastinal and peripheral pleura, and fissures) in the anterior and posterior aspect
of the upper lobes and the posterior aspect of the lower lobes.
• It is not associated with vascular distortion.
• CT shows subpleural areas of low attenuation, usually with a well-defined wall.

72. Paraseptal emphysema. Axial CT at the level of the upper lobes. Predominant paraseptal emphysema in a COPD
patient appearing as areas of low attenuation mainly distributed along the peripheral and mediastinal pleura on the
left side. Note associated centrilobular emphysema.

73. Paraseptal Emphysema (PSE)
• Rows of paraseptal emphysema may mimic honeycombing, but the cyst size is
usually larger than honeycomb cysts, and architectural distortion is not
present.
• In addition, as opposed to PSE, honeycombing is most often made of several
layers of cysts.
• PSE is often associated with multifocal areas of centrilobular emphysema and CT
findings of inflammatory changes in and around the small airways.

74. Paraseptal emphysema: typical CT findings. CT
image at the level of aortic arch shows
multiple bullae adjacent to the pleura and
along interlobular septa (arrow).
Centrilobular and paraseptal emphysema. High-
resolution CT image shows centrilobular emphysema
(arrowheads) with preserved centrilobular core
structures (small arrows). In subpleural location,
paraseptal emphysema is seen (curved arrows).

75. EMPHYSEMA

76. Bullae
• Bullae are seen as avascular low-attenuation areas that are > 1 cm in diameter, and
that can have a thin but perceptible wall.
• The bullae are often multiple and associated with emphysema of any type.
• Bullae are often located in the upper lobes in both CLE and in PSE, but are more
evenly distributed in the lungs of patients with PLE.
• Bullous emphysema is a pattern characterised by multiple large avascular
lucencies partly bounded by a thin wall.
• Bullae may be large enough to compress the adjacent lung parenchyma.

77. Bullous emphysema
(A) Coronal reformat. (B) Coronal average image (200-mm-thick slab) giving a rendering of chest X-ray equivalent.

78. Bullae
• Although such compression is usually relatively mild, it may result
occasionally in relaxation atelectasis appearing as a parenchymal band or a
mass-like opacity.
• Most patients having bullous lung disease have concomitant centrilobular,
panlobular or paraseptal emphysema.
• The term giant bullous emphysema has been used to describe the presence of
bullae occupying at least once-third of a hemithorax.
• Giant bullae may be compressive not only on the underlying lung
parenchyma but also on the diaphragm and the right atrium with the risk of
tamponade

79. Emphysema Associated with Interstitial Pneumonias
• Emphysema associated with interstitial pneumonias, which include respiratory
bronchiolitis associated with interstitial lung disease (RB-ILD), desquamative
interstitial pneumonia (DIP) or other interstitial pneumonias may occur in heavy
smokers, particularly those having COPD.
• The association of emphysema and usual interstitial pneumonia (UIP) is
responsible for a specific CT pattern in which extensive emphysema involves the
upper lung and honeycombing the bases.
• In such a particular situation, restrictive and obstructive disease counteract each
other, explaining why these patients present with normal or almost normal lung
volumes and FEV1 despite a significant drop of diffuse capacity of carbon
monoxide and a deep hypoaxemia at exercise.

80. Large Airway Disease
• The commonest CT finding of remodelling of bronchi is bronchial wall
thickening, which is common in smokers, more particularly those with functional
impairment, and more particularly those presenting clinical symptoms of chronic
bronchitis.
• Bronchial wall and lumen irregularities are commonly visualised on CT, reflecting
remodelling and deficit in cartilage.
• Evidence of moderate tubular (cylindrical) bronchiectasis (most in the lower
lobes) is common (29–58%).
• Bronchiectasis is associated with severe airflow obstruction, more severe COPD
exacerbation, lower airway bacterial colonisation, and increased sputum
inflammatory markers.

81. COPD patient with airway disease predominant phenotype. Axial CT at the levels of the upper (A) and
lower (B) parts of the chest. Few small centrilobular and paraseptal emphysematous spaces in the upper
lobes. Bronchial wall thickening, slight bronchial dilatation and lung parenchyma hypoattenuation reflecting
obstructive bronchiolitis in the lower lobes.