Diagnostic Imaging of Chest Trauma

1. Chest
Chest Trauma

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. Chest Trauma
1-Soft Tissues
2-Ribs
3-Sternum
4-Clavicles & Scapulae
5-Spine
6-Pleura
7-Lung
8-Trachea & Bronchi
9-Diaphragm
10-Mediastinum

7. 1-Soft Tissues :
a) Foreign bodies
b) Surgical emphysema
2-Ribs :
a) Simple fracture
b) Flail chest

8. 3-Sternum :
a) Fracture
b) Sternoclavicular dislocation
4-Clavicles & Scapulae :
-Fracture

9. 5-Spine :
a) Fracture :
-Multiple in 10%
-Thoracic spine injuries have a much higher
incidence of neurological deficit than cervical or
lumbar spine injuries
b) Cord trauma
c) Nerve root trauma :
-Especially to the brachial plexus

10. 6-Pleura :
a) Pneumothorax
b) Hemothorax

11. a) Pneumothorax :
1-Definition
2-Etiology
3-Radiographic Features
4-Tension Pneumothorax

12. 1-Definition :
-Refers to the presence of air in the pleural space
2-Etiology :
a) Primary Spontaneous
b) Secondary Spontaneous
c) Iatrogenic
d) Traumatic

13. a) Primary Spontaneous :
-A primary spontaneous pneumothorax is
one which occurs in a patient with no
known underlying lung disease
-Tall and thin people are more likely to
develop a primary spontaneous
pneumothorax

14. b) Secondary Spontaneous :
-When the underlying lung is abnormal , a
pneumothorax is referred to as secondary
spontaneous
-There are many pulmonary diseases which
predispose to pneumothorax including :
a) Cystic Lung Disease
b) Parenchymal Necrosis
c) Others

15. a) Cystic Lung Disease :
1-Bullae , blebs
2-Emphysema , asthma
3-Pneumocystis carinii pneumonia (PCP)
4-Honeycombing , end stage interstitial lung disease
5-Lymphangiomyomatosis (LAM)
6-Langehans cell histiocytosis (LCH)
7-Ankylosing spondylitis (due to apical lung changes)
8-Cystic fibrosis

16. b) Parenchymal Necrosis :
1-Lung abscess , necrotic pneumonia , septic
emboli , fungal disease & TB
2-Cavitating neoplasm , metastatic osteogenic
sarcoma
3-Radiation necrosis
c) Others :
-Catamenial : recurrent spontaneous
pneumothorax during menstruation , associated
with endometriosis of pleura

17. c) Iatrogenic :
1-Percutaneous biopsy
2-Barotrama , ventilator
3-Radiofrequency (RF) ablation of lung
mass
d) Traumatic :
-Lung laceration
-Tracheobronchial rupture

18. 3-Radiographic Features :
a) Upright Position
b) Supine Position
c) Other Positions
d) Size of Pneumothorax

19. a) Upright Position :
-Visible visceral pleural edge see as a very thin sharp white
line
-No lung markings are seen peripheral to this line
-The peripheral space is radiolucent compared to adjacent
lung
-The lung may completely collapse
-The mediastinum should not shift away form the
pneumothorax unless a tension pneumothorax is present
-Subcutaneous emphysema and pneumomediastinum may
also be present

22. Arrows point to thin white visceral pleural line which
is the single best sign for a pneumothorax

28. With SC emphysema

29. b) Supine Position :
-Deep sulcus sign :
Anterior costophrenic angle sharply delineated
When the patient is in the supine position , air in
the pleural space (pneumothorax) collects
anteriorly and basally within the nondependent
portions of the pleural space , if air collects
laterally rather than medially , it abnormally
deepens the lateral costophrenic angle and
produces the deep sulcus sign
-Double diaphragm sign :
Air may outline the anterior portions of the
hemidiaphragm and cause visualization of
the anterior costophrenic sulcus

31. Deep sulcus sign

32. Deep sulcus sign

33. Double diaphragm sign

34. c) Other Positions :
1-Lateral decubitus radiograph :
-Should be done with the suspected side up
-The lung will then fall away from the chest
wall
2-Expiratory chest radiograph :
-Lung becomes smaller and denser
3-CT most sensitive

35. Lateral decubitus

36. Inspiratory film
Expiratory film (The image shows
increase in apparent size of the
pneumothorax on the expiratory
view compared to the inspiratory
view , arrows show the pleura)

37. d) Size of Pneumothorax :
Average distance (AD in cm) = (A + B + C)/3
% Pneumothorax = AD (in cm) ,
e.g. AD of 1 cm corresponds to a 10%
pneumothorax
AD of 4 cm corresponds to a 40%
pneumothorax

39. 4-Tension Pneumothorax :
a) Definition
b) Radiographic Features

40. a) Definition :
-occurs when intrapleural air accumulates
progressively in such a way as to exert
positive pressure on mediastinal and
intrathoracic structures

41. b) Radiographic Features :
-Over expanded hemithorax
-Shift of the mediastinum to the contralateral
side
-Depression of the hemidiaphragm

42. Tension pneumothorax on left (blue arrow) is displacing the heart and
mediastinal structures to the right (red arrow) ; this case also shows
a deep sulcus sign on the left (yellow arrow)

43. The left lung is completely compressed (arrowheads) , the trachea is
pushed to the right (arrow) , the heart is shifted to the contralateral
side , note right heart border is pushed to the right (red line) , the left
hemidiaphragm is depressed (orange line)

49. b) Hemothorax :
1-Definition
2-Etiology
3-Radiographic Features

50. 1-Definition :
-Means blood within the chest , is a term usually
used to described a pleural effusion due to
accumulation of blood
-If a hemothorax occurs concurrently with
a pneumothorax it is then termed
a hemopneumothorax
-A tension hemothorax refers to hemothorax that
result from massive intrathoracic bleeding
causing ipsilateral lung compression and
mediastinal displacement

51. 2-Etiology :
a) Traumatic
b) Spontaneous

52. a) Traumatic :
-In 25-50% of patients with blunt chest
trauma and 60-80% of patients with
penetrating wounds

53. b) Spontaneous :
1-Primary Spontaneous :
-Spontaneous pneumothorax , spontaneous
hemopneumothorax
2-Secondary Spontaneous :
a) Neoplastic
b) Anticoagulant Medication
c) Vascular Rupture

54. a) Neoplastic :
1-Intra thoracic malignancy :
-Usually occurs with thoracic wall tumors
Thoracic wall schwanommas
Thoracic wall neurofibromas
2-Soft tissue tumors :
-Sarcomas , thoracic angiosarcomas
3-HCC with thoracic invasion or thoracic metastases
4-Lung cancer is a distinctly uncommon cause of
hemothorax even in the setting of pleural extension

55. b) Anticoagulant Medication
c) Vascular Rupture :
1-Aortic Dissection
2-Pulmonary AVM
3-Pulmonary Infarction
4-Thoracic Endometriosis

56. 3-Radiographic Features :
a) Plain Radiography
b) CT

57. a) Plain Radiography :
-A large hemothorax may be seen as a
pleural effusion
-It can be almost impossible to differentiate
a hemothorax from other causes of pleural
effusion

58. There is complete opacification of the right hemithorax with slight shift
of the trachea towards the left , fluid is seen tracking up the lateral
margin of the thorax (red arrow) , the clue to the diagnosis is the
bullet (blue circle)

60. Pneumohemothorax , after a stab injury . blood accumulates in the
pleural space (hemothorax) , no pulmonary vasculature can be
noted beyond the visceral pleural line in the upper lung due to the
accumulation of air in the same space (pneumothorax)

61. b) CT :
CT is useful in determining the nature of pleural
fluid in the setting of trauma by assessing the
attenuation value , blood in the pleural space
typically has an attenuation of 35-70 HU
-Pleural fluid attenuation measurement should be
routine in the interpretation of chest trauma CT
to distinguish simple fluid from acute blood
-In the setting of trauma , there may be other
ancillary features such as pulmonary
contusions & lacerations

63. 7-Lung :
1-Contusion
2-Hematoma
3-Laceration
4-Fat Embolism
5-Aspiration Pneumonia
6-Foreign Body
7-Pulmonary Edema
8-Adult Respiratory Distress Syndrome

64. 1-Contusion :
a) Definition
b) Radiographic Features

65. a) Definition :
-Refers to an interstitial and/or alveolar lung
injury without any frank laceration
-It usually occurs secondary to non-
penetrating trauma

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

67. 1-Plain Radiography :
-Not sensitive
-Faint patchy consolidative regions following
history of blunt trauma
-Usually shows rapid improvement with time
usually days

70. 2-CT :
Typically seen as focal non segmental
(typically crescentic) areas of parenchymal
opacification
-Can have sub-pleural sparing with smaller
contusions which can be a distinguishing
feature
-Commoner posteriorly and in lower lobe

73. 2-Hematoma :
-Usually appears following resolution of
contusion
-Round well-defined nodule
-Resolution in several weeks

74. 3-Laceration :
a) Definition
b) Classification
c) Radiographic Features

75. a) Definition :
-Results from frank laceration of lung
parenchyma secondary to trauma , there
is almost always concurrent contusion
-There is a linear tear (may be
radiographically visible) that becomes
round or ovoid (pneumatocele) with time

76. b) Classification :
Type I : compression rupture
Type II : compression shear
Type III : direct puncture / rib penetration
Type IV : adhesion tears

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

78. 1-Plain Radiography :
Pattern can be similar to contusion but can
also have added rib fractures and
pneumothorax

80. Flail Chest , CXR shows multiple rib fractures (black arrows) with some
ribs fractured in two or more places , there is also a pulmonary
contusion (red arrow) and subcutaneous emphysema (white arrow)

81. 2-CT :
-Regions of pulmonary contusion with added blebs
(pneumatocoeles) with air fluid levels
-Due to normal pulmonary elastic recoil , lung
tissues surrounding a laceration often pull back
from the laceration itself , this results in the
laceration manifesting at CT as a round or oval
cavity instead of having the linear appearance
typically seen in other solid organs

82. Pulmonary Laceration , there is a soft tissue density in the right lower
lobe (black circle) with several small air-containg cavities within it in
a patient with recent trauma

83. Axial CT shows a hole in the lung with air-fluid level (arrow) surrounded
by ground glass opacity (arrowheads) in a trauma patient , findings
represent pulmonary laceration surrounded by contusion

86. 4-Fat Embolism :
a) Etiology
b) Radiographic Features

87. a) Etiology :
-Lipid emboli from bone marrow enter
pulmonary and systemic circulation
-1 to 2 days post-trauma
-Resolves in 1-4 weeks
-Frequently CNS is also affected

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

89. 1-Plain Radiography :
-Resembles pulmonary edema but normal
heart size and pleural effusion is
uncommon

90. The chest x ray showed bilateral homogenous opacities

92. 2-CT :
-Three predominate patterns are observed :
1-Ground-glass change with geographic
distribution
2-Ground glass opacities with interlobular
septal thickening
3-Nodular opacities

93. A 17 year old man with a
comminuted femur fracture
Top , A: HRCT scan obtained the
second day after injury shows
ground-glass opacities
Bottom , B: HRCT at a lower level
shows ground-glass opacities
confined to some lobules with
a sharp margination between
areas of involved and
noninvolved lung resulting in a
geographic appearance , also
noted is smooth and nodular
interlobular septal thickening

94. A 19 year old man at 2 days after
femur shaft fractures
Top , A: HRCT scan obtained at
the lower lung zones reveals a
predominantly peripheral
distribution of ground-glass
opacities associated with
smooth and nodular septal
thickening
Bottom , B: HRCT obtained at a
lower level shows relative
sparing of some secondary
lobule

95. Top , A: HRCT obtained just
below the tracheal
bifurcation reveals a
predominantly nodular
pattern , note that
bronchovascular bundles
are thin and smooth
Bottom , B: HRCT obtained
at the level of pulmonary
veins shows similar
pattern and severity of
findings

96. 5-Aspiration Pneumonia
6-Foreign Body
7-Pulmonary Edema :
-Following blast injuries or head injury
(neurogenic edema)
8-Adult Respiratory Distress Syndrome :
-Widespread air-space shadowing
appearing 24-72 hours after injury

97. 8-Trachea & Bronchi :
-Laceration or fracture :
Initially surgical emphysema and
pneumomediastinum followed by collapse
of the affected lung or lobe

98. 9-Diaphragm : Rupture
a) Incidence
b) Radiographic Features

99. a) Incidence :
-In 3-7% of patients with blunt and 6-46% of
patients with penetrating thoraco-
abdominal trauma
-Ninety percent of tears occur on the left
side

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

101. 1-Plain Radiography :
-Herniated stomach or bowel above the
diaphragm
-Pleural effusion
-A supradiaphragmatic mass or a poorly
visualized or abnormally contoured
diaphragm

105. 2-CT :
a) Direct CT Signs :
1-Segmental Diaphragmatic Defect (focal and
abrupt loss of continuity in the diaphragm)
2-Dangling Diaphragm (the free edge of the torn
diaphragm which curls inward from its normal
course toward the center of the body forming a
comma shaped or curvilinear structure)
3-Absent Diaphragm (absence of part or all of the
hemidiaphragm without demonstration of a tear)

106. b) Indirect CT Signs Related to
Herniation:
1-Herniation through a Defect
2-Collar Sign
3- & 4-Hump and Band Signs
5-Dependent Viscera Sign
6-Sinus Cutoff Sign
7-Abdominal Content Peripheral to the
Diaphragm or Lung Sign
8-Elevated Abdominal Organs Sign

108. 10-Mediastinum :
a) Aortic Injury
b) Mediastinal Hematoma
c) Pneumomediastinum
d) Hemopericardium
e) Esophageal Rupture

109. a) Aortic Injury :
1-Incidence
2-Radiographic Features

110. 1-Incidence :
-90% of aortic ruptures occur just distal to
the origin of the left subclavian artery
-More with blunt trauma

111. 2-Radiographic Features :
a) Plain Radiography
b) CT

112. a) Plain Radiography :
1-Widening of the mediastinum
2-Abnormal aortic contour
3-Tracheal displacement to the right
4-Nasogastric tube displacement to the right of the
T4 spinous process
5-Thickening of the right paraspinal stripe
6-Depression of the left mainstem bronchus > 40°
below the horizontal
7-Loss of definition of the aortopulmonary window

113. Normal CXR Aortic Injury

114. b) CT :
1-Non-Contrast :
-May show indirect signs of aortic injury :
a) Mediastinal hematoma
b) Periaortic fat stranding
c) Other chest injuries

115. 2-CTA :
a) Signs of mediastinal hematoma :
-Abnormal soft tissue density around the
mediastinal structures
-Location is important , periaortic hematoma
much more suggestive of aortic injury than
isolated mediastinal hematoma remote
from the aorta

116. b) Signs of aortic injury :
-Intraluminal filling defect (intimal flap or
clot)
-Abnormal aortic contour (mural hematoma)
-Pseudoaneurysm
-Extravasation of contrast

118. b) Mediastinal Hematoma :
-Blurring of the mediastinal outline

119. c) Pneumomediastinum :
1-Etiology
2-Radiographic Features

120. 1-Etiology :
1-Blunt or penetrating chest trauma
2-Secondary to thoracic , neck or
retroperitoneal surgery
3-Esophageal perforation
4-Tracheobronchial perforation
5-Vigorous exercise , child birth , valsalva
maneuver
6-Asthma
7-TB
8-Perforation of a hollow abdominal viscous (with
extension of gas via the retroperitoneal space)

121. 2-Radiographic Features :
-Small amounts of air appear as linear or
curvilinear lucencies outlining mediastinal
contours :
1-Thymic sail sign
2-Air anterior to the pericardium
3-Air around the pulmonary artery or its major
branches
4-Air around the aorta or its major branches
5-Double bronchial wall sign
6-Subcutaneous emphysema

127. d) Hemopericardium :
1-Definition
2-Radiographic Features

128. 1-Definition :
-Accumulation of blood in the pericardium
2-Radiographic Features :
->250 mL is necessary to be detectable
-Subpericardial fat stripe measures >10 mm (a
stripe 1 to 5 mm can be normal)
-Symmetrical enlargement of cardiac silhouette
(water-bottle sign)

129. Pericardial effusion on both chest radiograph and axial CT , Red arrow points to
fat outside of pericardium , Green arrow points to pericardial space which is
8 mm in this patient (<4 mm is normal) , Yellow arrow points to fat outside
of heart and the blue arrow to the myocardium

130. Water bottle sign

132. e) Esophageal Rupture :
1-Incidence
2-Radiographic Features

133. 1-Incidence :
-Is a rare but serious medical emergency
with a very high mortality rate , especially
if the diagnosis is delayed
-More in males

134. 2-Radiographic Features :
a) Plain Radiography
b) Contrast Enhanced Esophography
c) CT

135. a) Plain Radiography :
-Chest radiographs are nonspecific and
usually show wide mediastinum , left
pleural effusion or hydropneumothorax
-Pneumomediastinum is common but is a
nonspecific finding

136. 77 year old man with esophageal rupture , portable chest radiograph
shows subtle retrocardiac opacity (arrow) and blunted left
costophrenic angle (arrowhead) consistent with mild pleural fluid
and overlying consolidation

137. b) Contrast Enhanced Esophography :
-Extravasation of contrast material into the
mediastinum

139. c) CT :
-Focal esophageal wall thickening
-Periesophageal fluid collections
-Free mediastinal air
-Contrast extravasation into the
mediastinum and pleural space

140. 77 year old man with esophageal rupture , CT of the abdomen and pelvis with oral and intravenous
contrast , Axial (A) CT at the level of the aortic arch shows a dilated, air-and-fluid-filled thoracic
esophagus (arrow) , Axial (B) and coronal (C) show extraluminal contrast and air (large arrows)
extending to the left of the distal esophagus (e) , also note associated bilateral pleural fluid (B, pf)
and overlying left-lung base atelectasis (B, arrowheads)

141. Acute mediastinitis in a patient
with esophageal perforation
(a) CT+C shows esophageal wall
thickening (arrow) and a
posterior mediastinal air-fluid
collection (arrowhead) abutting
the esophagus
(b) CT+C shows the probable site
of esophageal perforation
(arrowhead) and esophageal
wall thickening (arrow)