This document provides information on recognizing three common lung conditions: atelectasis, pleural effusion, and pneumonia. It describes the signs and patterns of each condition, including how they appear on chest x-rays. For atelectasis, it outlines different types like subsegmental and compressive atelectasis. For pleural effusion, it discusses characteristics like transudate vs. exudate effusions and how they can be positioned in the lungs. Pneumonia types covered include lobar, segmental, interstitial, round, and cavitary patterns. Localization clues and resolution of these conditions is also addressed.

1. Recognizing Atelectasis,
Pleural Effusion and
Pneumonia

2. Recognizing
Atelectasis
01 02
03
Table of contents
2
Recognizing
Pleural Effusion
Recognizing
Penumonia

3. RECOGNIZING
PLEURAL
EFFUSION
01
Recognizing
Atelectasis

4. What is Atelectasis?
Loss of volume in some or all of the lung, usually leading to
increased density of the lung involved.
- part of the lung involved becomes whiter (denser or more
opaque)
- fluid or soft tissue density has substituted the air or the air in the
lung is resorbed (as it can be in atelectasis)

6. Signs of Atelectasis
*Toward the atelectasis

7. Increase in the density
of the affected lung
Displacement of the
interlobar fissures

8. Trachea

9. Heart

10. Hemidiaphragm

11. Overinflation of unaffected ipsilateral lobe or
contralateral lung

12. Types of Atelectasis
1. Subsegmental Atelectasis (Discoid or platelike)
2. Compressive Atelectasis (Passive)
a. Round Atelectasis
3. Obstructive Atelectasis

13. 1. Subsegmental Atelectasis (Discoid or platelike)
● associated with deactivation of surfactant
○ leads to collapse of airspaces in a
nonsegmental or nonlobar distribution
(not due to bronchial obstruction)
● produces linear densities of varying thickness
usually parallel to the diaphragm
○ most commonly at the lung bases
● does not produce a sufficient amount of volume
loss to cause a shift of the mobile thoracic
structures
● looks identical to linear scarring
○ disappears within a matter of days with
resumption of normal, deep breathing,
whereas scarring remains

14. 2. Compressive Atelectasis (Passive)
● due to passive compression of the lung can
be caused by:
○ poor inspiratory effort in which there is
passive atelectasis of the lung at the
bases (Fig. A)
○ large pleural effusion, large
pneumothorax, or a space-occupying
lesion (such as a large mass in the
lung) (Fig. B)

15. 2. Compressive Atelectasis (Passive)
● when caused by a large effusion or
pneumothorax, the loss of volume associated
with compressive atelectasis may balance the
increased volume produced by either fluid (as in
pleural effusion) or air (as in pneumothorax)
● in an adult patient with an opacified hemithorax,
no air bronchograms, and little or no shift of the
mobile thoracic structures, it is important to
suspect an obstructing bronchogenic
carcinoma, perhaps with metastases to the
pleura

16. 2. Compressive Atelectasis (Passive)
● Pitfall:
● Be suspicious of compressive atelectasis if the patient has taken less than an 8
posterior-rib breath.
○ Solution: Check the lateral projection for confirmation of the presence of real
airspace disease at the base

17. a. Round Atelectasis (Passive)
● usually seen at the periphery of the lung base
● develops from a combination of prior pleural
disease (such as from asbestos exposure or
tuberculosis) and formation of a pleural effusion
that produces adjacent compressive atelectasis
● underlying pleural disease leads to a portion of
the atelectatic lung becoming “trapped” when
pleural effusion recedes
○ produces a masslike lesion that can be
confused for a tumor
○ on chest CT scan, bronchovascular
markings produce a comet-tail
appearance

18. 3. Obstructive Atelectasis
● associated with the resorption of air from the
alveoli, through the pulmonary capillary bed,
distal to an obstructing lesion of the
bronchial tree

20. Patterns of Collapse in Obstructive Atelectasis
1. Right Upper Lobe Atelectasis
A. Frontal radiograph:
● upward shift of the minor fissure
● rightward shift of the trachea
● combination of a hilar mass and the
upward shift of the minor fissure
produces S sign of Golden
B. Lateral radiograph:
● upward shift of the minor fissure
● forward shift of the major fissure

21. 2. Left Upper Lobe Atelectasis
A. Frontal radiograph:
● increased density at left hilum
● leftward shift of the trachea
● may be an elevation with tenting or
peaking of left hemidiaphragm
● compensatory overinflation of lower lobe
B. Lateral radiograph:
● forward displacement of major fissure
● opacified upper lobe forms a band of
increased density parallel to the sternum

22. 3. Lower Lobe Atelectasis
A. Frontal radiograph:
● both right and left lower lobes collapse to
form a triangular density (Fig. A)
● downward shift of major fissure (Fig. C)
● shift of the heart towards the atelectasis
● elevation of the hemidiaphragm on the
affected side
B. Lateral radiograph:
● both downward and posterior displacement
of the major fissure (Fig. B)
○ until the completely collapsed lower
lobe forms a small triangular density
at the posterior costophrenic angle

23. 3. Lower Lobe Atelectasis
● In the critically ill patient, atelectasis occurs most frequently in the left lower lobe
○ Always check the left hemidiaphragm to be sure it is seen in its entire extent through the heart
shadow
■ left lower lobe atelectasis will manifest by disappearance (silhouetting) of all or part of the left
hemidiaphragm (Fig. C)

24. 4. Right Middle Lobe Atelectasis
A. Frontal radiograph:
● triangular density with its base silhouetting
the right heart border and its apex pointing
the lateral chest wall
● downward shift of minor fissure
B. Lateral radiograph:
● triangular density with its base directed
anteriorly and its apex at the hilum
● shift of minor fissure inferiorly and major
fissure superiorly

25. 5. Too Low Endotracheal Tube

26. 6. Atelectasis of the Entire Lung
A. Frontal radiograph:
● opacification of the atelectatic lung
● shift of all mobile thoracic structures towards
the atelectasis
● hemidiaphragm on the side of atelectasis is
silhouetted by the above nonaerated lung
B. Lateral radiograph:
● hemidiaphragm on the side of atelectasis is
silhouetted by the above nonaerated lung
(only one hemidiaphragm is seen)

27. How Atelectasis resolves
Resolves within hours or lasts for many days once the
obstruction has been removed
- slowly resolving lobar or whole-lung atelectasis may manifest patchy areas
of airspace disease surrounded by progressively increasing zones of
aerated lung until the atelectasis has completely cleared.

28. RECOGNIZING
PLEURAL
EFFUSION
02
Recognizing
Pleural Effusion

29. What is Pleural Effusion?
Abnormal accumulation of fluid in the pleural cavity/space
between the visceral pleura and the parietal pleura
- normally 2-5 mL of pleural fluid in the pleural space
- first step in detecting pleural effusion is usually conventional
radiography

31. Types of Pleural Effusion
a. Transudate
- formed due to increased hydrostatic pressure or decreased
osmotic pressure
- Congestive heart failure: most common cause
b. Exudate
- formed due to inflammation
- Malignancy: most common cause
- empyema, hemothorax, chylothorax

32. Side-Specificity of Pleural Effusion
a. Diseases that produce bilateral effusions:
- CHF
- same amount of fluid in each hemithorax
- Parapneumonic effusion or malignancy
- different amount of fluid in each hemithorax
- SLE
b. Diseases that produce unilateral effusion (either side):
- TB and other diseases associated with infectious agents
- Pulmonary thromboembolic disease
- Trauma
c. Diseases that produce left-sided effusion:
- Pancreatitis, distal thoracic duct obstruction, Dressler syndrome
d. Diseases that produce right-sided effusion:
- Abdominal disease related to the liver or ovaries
- Meigs syndrome (ovarian tumor associated with right pleural effusion and
ascites)
- Proximal thoracic duct obstruction
- Rheumatoid arthritis

33. Dressler Syndrome

34. Appearances of Pleural
Effusion

35. a. Subpulmonic Effusion

36. a. Subpulmonic Effusion

37. Blunting of Costophrenic Angles

38. Meniscus Sign

39. Effect of Patient positioning

40. Patient positioning: Lateral decubitus

41. ● When the hemithorax contains about 2 L of fluid, the entire
hemithorax will be opacified.
● As fluid fills the pleural space, the lung tends to undergo
passive collapse (atelectasis).
● Large effusions can act like a mass and displace the heart
and trachea away from the side of opacification.
Opacified Hemithorax

43. ● Adhesions in the pleural space, caused most often by an
old infection or hemothorax, may limit the normal mobility of
a pleural effusion so that it remains in the same location no
matter what position the patient assumes.
● Suspected when an effusion has an unusual shape or
location in the thorax
Loculated Effusions

44. Loculated
Effusions

45. ● Pseudotumors (also called vanishing tumors) are sharply
marginated collections of pleural fluid contained either
between the layers of an interlobar pulmonary fissure or in a
subpleural location just beneath the fissure.
● They are transudates that almost always occur in patients
with congestive heart failure.
● Imaging findings of a pseudotumor are characteristic and
should not be mistaken for an actual tumor.
Fissural Pseudotumors

47. ● Is a form of pleural effusion in which the fluid assumes a
thin, bandlike density along the lateral chest wall, especially
near the costophrenic angle.
● The lateral costophrenic angle tends to maintain its acute
angle with a laminar effusion.
● They are usually not free-flowing.
● Can be recognized by the band of increased density that
separates the air-filled lung from the inside margin of the
ribs at the lung base on the frontal chest radiograph.
Laminar Effusions

48. Laminar
Effusions

49. ● Presence of both air in the pleural space (pneumothorax)
and abnormal amounts of fluid in the pleural space (pleural
effusion or hydrothorax).
● Unlike pleural effusion alone, whose meniscoid shape is
governed by the elastic recoil of the lung, a
hydropneumothorax produces an air-fluid level in the
hemithorax marked by a straight edge and a sharp,
air-over-fluid interface when a horizontal x-ray beam is
exposed.
Hydropneumothorax

52. 03
RECOGNIZING
PNEUMONIA
Recognizing
Pneumonia

53. Defined as consolidation of the lung produced by
inflammatory exudate, usually as a result of an infectious
agent.
- Most pneumonias produce airspace disease, either lobar
or segmental. Others demonstrate interstitial disease,
while some also present both.
What is Pneumonia?

55. ● Appears denser (whiter) than surrounding normal lung.
● May contain Air Bronchograms
● If airspaces involved- appears fluffy and margins are
indistinct.
● For interstitial pneumonia- prominence of interstitial
markings noted.
● Usually homogenous in density
● In some types of pneumonia, atelectasis may be noted.
General Characteristics of
Pneumonia

58. ● LOBAR
● SEGMENTAL
● INTERSTITIAL
● ROUND
● CAVITARY
Patterns of Pneumonia

59. LOBAR PNEUMONIA
● Prototypical Lobar pneumonia is caused by Streptococcus
pneumoniae.
● In its classic form, the disease fills most or all of a lobe of
the lung.
● If pneumonia is bound by a fissure, the margins may be
sharply distinct. If not bound by a fissure, it will have an
indistinct and irregular margin.
● Almost always produce a silhouette sign
● May contain air bronchograms if it involves the central
portions of the lung.

60. LOBAR
PNEUMONIA

61. ● Prototypical Bronchopneumonia is caused by
Staphylococcus aureus and other Gram Negative Bacteria
such as Pseudomonas aeruginosa.
● Is spread centrifugally via the tracheobronchial tree to many
foci in the lung. Therefore, it frequently involves several
segments of the lung simultaenously.
● Margins tend to be fluffy and indistinct.
● Airbronchograms usually not present.
● Atelectasis may be noted.
SEGMENTAL PNEUMONIA

62. SEGMENTAL
PNEUMONIA

63. ● Prototypes for Interstitial Pneumonia are Viral pnuemonia,
Mycoplasma pneumoniae and Pneumocystis pneumonia in
AIDS patients.
● Tends to involve the airway walls and alveolar septa and may
produce a fine, reticular pattern in the lungs.
● Most cases eventually spread to the adjacent alveoli and
produce patchy or confluent airspace disease
INTERSTITIAL PNEUMONIA

64. ● PCP is the most common clinically recognized infection in
patients with AIDS.
● It classically presents as a perihilar, reticular interstitial
pneumonia or as airspace disease that may mimic the
central distribution pattern of pulmonary edema
● There are usually no pleural effusions and no hilar
adenopathy.
INTERSTITIAL PNEUMONIA
(Pneumocystis carinii pneumonia)

65. INTERSTITIAL
PNEUMONIA

66. ● Some pneumonias may assume a spherical shape on chest
radiographs.
● Almost always posterior in the lungs, usually in the lower
lobes.
● Causative Agents: Haemophilus influenzae, Streptococcus
and Pneumococcus.
● May be confused with a tumor mass.
ROUND PNEUMONIA

67. ROUND
PNEUMONIA

68. ● The prototypical organism produciing cavitary pneumonia is
Mycobacterium tuberculosis.
● Cavitation is common in postprimary tuberculosis (TB)
(reactivation tuberculosis) but rare in primary TB.
● The cavities are usually located in the upper lobes, are
bilateral and thin-walled, have a smooth inner margin, and
contain no air-fluid level.
● Transbronchial spread may be suggestive of infection with
Mycobacterium tuberculosis.
CAVITARY PNEUMONIA

69. CAVITARY
PNEUMONIA

71. ● Almost always occurs in the most dependent portions of the
lung.
● In upright position, the most dependent portion of the lung is
the lower lobes.
● In recumbent position, aspiration usually occurs into the
superior segments of the lower lobes or the posterior segment
of the upper lobes.
● The right side is more often affected than the left because of the
straighter and wider nature of the right main bronchus.
● Acute aspiration will produce radiographic findings of airspace
disease.
ASPIRATION

73. ● Determining the location of a pneumonia may provide clues
to the causative organism and the presence of associated
pathology.
● It is always best to localize disease using two views taken at
90° to each other (orthogonal views) such as a frontal and
lateral chest radiograph.
● Computed tomography (CT) may further localize and
characterize the disease and demonstrate associated
pathology.
LOCALIZING PNEUMONIA

74. ● If two objects of the same radiographic density touch each
other, then the edge between them disappears
● The silhouette sign is valuable in localizing and identifying
tissue types throughout the body
SILHOUETTE SIGN

79. ● On the lateral chest radiograph, the thoracic spine
normally appears to get darker from the shoulder girdle to
the diaphragm.
● When diseases of soft tissue or fluid density involves the
posterior portion of the lower lobe, more of the x-ray beam
will be absorbed by the new, added density, and the spine
will appear to become “whiter” just above the posterior
costophrenic sulcus.
SPINE SIGN

81. HOW PNEUMONIA RESOLVES
● Pneumonia can resolve in 2 to 3 days if the organism is
sensitive to the antibiotic administered.
● Most pneumonias typically resolve from within
(vacuolization), gradually disappearing in a patchy fashion
over days, or weeks.

84. THANK YOU
FOR LISTENING!