Lung and Thorax Ultrasound

1. Lung & thorax
SAH & RNSH 2011
Critical Care Ultrasound Course
Thanks to:
Dr Paul Atkinson
Dr Bishr Faheem
Dr Daniel Lichtenstein

2. Scanning the lung
• Why scan the lung?
• Probe & scanner settings
• Technique
• Landmarks
• US findings
• Terminology: the lung profiles
• Matching the findings to the disease
• Sticking needles & tubes in the lung
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3. Why scan the lung?
• Diagnosis
• Air in pleura: PTX
• Fluid in pleura: blood, pus
• Fluid in lung tissue: APO/ pneumonia /
ARDS
• Consolidated lung tissue: pneumonia /
contusion / infarct (PE) / cancer
• Procedures
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4. Why bother?
• Lung US is more accurate than CXR for:
• PTX (>95% versus 50%)
• Pleural fluid (20ml versus 200ml)
• APO sens 97%, spec 94%, acc 95%
• PE?? Sens 74% … 81% if add DVT
• It’s also
• Faster (2 min versus 19 min)
• Safer
• Repeatable 4

5. The Technique
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6. Patient position
! No need to sit patient up (eg trauma)
! In fact, accuracy for PTX is improved if
lying flat… just harder to get round the
back for pleural fluid
! Air rises
! Fluid sinks
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7. Probe
! Ideally the curved probe
! Linear array no anatomical info
! Phased array poor image quality
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8. Preset
! Abdo / FAST
! Not the commercial ‘lung’ settings
! Turn off filters
! Multibeam / compounding
! Tissue harmonics
! Why? You are looking for artefacts
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9. Depth
! Close up consolidation? = 5cm
! Just sliding / A / B lines? = 10cm
! Base of lung / diaphragm? = 15cm
! Making sure rockets are rockets? =
15cm
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10. Probe position
! Sagittal
! Right angles to the ribs
! Makes sure that the landmarks (rib
shadows) stay in view
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11. Find those ribs
‘RIB’
‘RIB’
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12. Look between the ribs
RIB
RIB
PLEURAL LINE (WHERE THE ACTION IS)
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13. So:
! Curved probe
! FAST / abdo preset
! 10-15cm depth
! Turn off fancy filters
! Sagittal / long axis of patient
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14. Where will I scan?
Depends on clinical context
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15. The basic principle
! Air rises " scan highest point of the
chest
! Fluid sinks " scan lowest point
! Some diseases are patchy (eg
pneumonia, ARDS) " scan as much of
the lung as possible (at least look at
each lobe)
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16. Where will I scan?
! Cardiac arrest: highest point on each side
! Shock: 2 anterior (BLUE) points on each side
! Breathless: 3 points on each side
! Add 1 posterior (PLAPS) point
! Thorough look: as much of each lung as
possible (improves accuracy)
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17. BLUE points & PLAPS points
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18. BLUE points & PLAPS points
! What the %$#% ???
! Daniel Lichtenstein’s BLUE protocol
! BLUE is not an acronym
! PLAPS is, though
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19. BLUE points & PLAPS points
! Upper BLUE point = upper lobe
! Lower BLUE point = middle lobe /
lingula
! PLAPS point = lower lobe
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20. Lichtenstein’s BLUE points
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21. Lichtenstein’s BLUE points in theory
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22. Lichtenstein’s BLUE points in theory
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23. Lichtenstein’s BLUE points in practice
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24. Lichtenstein’s BLUE points in practice
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25. Lichtenstein’s PLAPS point
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26. PLAPS point
! ‘Postero- Lateral Alveolar / Pleural
Syndrome’
! What the %$#% ???
! Posterolateral = round the back
! Alveolar syndrome = consolidation
! Pleural syndrome = pleural fluid
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27. PLAPS point
! The PLAPS point is the lowest point of
the lung
! The Morison's Pouch of the
thorax’ (thanks to Dr Chris Wong)
! So this is where you find pleural fluid
! If there’s no fluid here, there’s no fluid
anywhere in the thorax!
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28. How to find the PLAPS point
! It’s the posterior continuation of the
lower BLUE point (as far around as you
can get the probe)
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29. How to find the PLAPS point
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30. How to find the PLAPS point
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31. Tip: watch out for the abdomen!
! If you scan the liver / spleen & think you’re still
above the diaphragm, it will resemble consolidation
! ESP if you are using linear probe
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32. Tip: Get round as far back as you can!
wrong right
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33. Tip: Get round as far back as you can!
wrong right
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34. Tip: Get round as far back as you can!
wrong right
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35. Normal lung
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36. NB: ‘normal lung’
! Pleural line looks like a ‘curtain’ sliding
back & forth
! Sparkle = scatter from air in lung
! You don’t really seeing normal lung at
all
! If it looks like liver:
! mirror
! hepatization
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37. What am I looking for?
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38. What am I looking for?
! Pleural fluid
! Pleural sliding
! A lines: reverb artefact from pleural line
! B lines: hyperechoic reverberation effect
from air/water interface
! C: consolidation
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39. Pleural fluid
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40. Pleural fluid
! Site: dependent regions
! Appearance:
! black = anechoic (fresh blood, transudate/
exudate)
! echogenic / stuff = blood, exudate
! Amount: as little as 20ml
! Sensitivity >97%, specificity 99-100%
(Sisley et al, J Trauma 1998)
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41. Pleural fluid
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42. Pleural fluid
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43. Pleural fluid
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44. Pleural fluid: caveats
! Pleural vs pericardial fluid (pericardial =
delimited by descending aorta)
! Peritoneal fluid (where’s the diaphragm?)
! Small traces of fluid: easy to miss
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45. Pleural or pericardial fluid?
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46. Duh! Just look all over the thorax

47. A, B & Z lines
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48. A, B & Z lines
! A lines = horizontal & static =
reverberation artefact from pleura
! B lines = vertical & move with resps
(prev ‘comet tails’) = thick vertical lines
which reach to edge of screen &
obliterate A lines
! Z lines = vertical, fade quickly, don’t
move with resps
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49. A lines
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50. A lines
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51. A lines
Horizontal artefacts
Only air is present
Present in dry lungs
Present in PTX
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52. B-line
B line
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53. B lines
Vertical artefacts
Air/fluid mix in interlobular septa
Equivalent of Kerley B lines
Not seen in PTX
Even 1 B line rules out PTX at that site
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54. B lines
Vertical
Bright
Obliterate A lines
Don’t fade!
Reach all the way to the edge of the
screen!
1 or 2 per lung field is OK
3 or more = ‘rockets’
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55. Z-lines(Note: A line maintained)
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56. Z lines
! ill defined
! DON’T move with respiration
! DON’T erase the A lines
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57. Lung rockets
‘When several B lines are visible in
a single scan, the pattern
evokes a rocket at lift-off, and
we have adopted the term ‘lung
rockets’’ (Lichtenstein p106)
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58. Lung rockets
3 or more B lines per lung field =
‘rockets’
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59. Not ‘comets’
International consensus dropped
the term (terminology is
confusing enough already)
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60. Rockets
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61. Rockets
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62. Top Tip
Up to 1/3 normal patients have rockets in
dependent regions
So if you see rockets in PLAPS points, it
doesn’t matter!
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63. Lung rockets = wet lungs
! Just in the bases = normal
! In all windows = cardiogenic oedema
! Patchy, with spared areas = non
cardiogenic oedema / widespread
pneumonia
! Localised = pneumonia / chronic
interstitial diseases eg fibrosis
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64. Test
Remember: 1 or 2 B lines are OK.
Lung is still dry at that point!
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65. A, B or Z lines? Dry or wet?
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66. A, B or Z lines? Dry or wet?
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67. A, B or Z lines? Dry or wet?
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68. A, B or Z lines? Dry or wet?
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69. Applications of lung rockets
! Diagnosis
! Is it his CCF or COPD playing up today?
! Fluid status
! is this guy with a crap LV overloaded today?
! Guiding fluid resuscitation
! Fill him up until the rockets appear
! Dialyse him until the rockets disappear
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70. Validation
! Volpicelli et al, Am J Emerg Med 2006 (24):
689-696
! N=300 (75 had AIS)
! Combined gold standard incl 1 month
follow up
!
sens
spec
! Rockets
85.7%
97.7%
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71. Just remember
! Not all vertical lines are B lines
! Z lines = puny
! pseudo-rockets with subcut emphysema (don’t
move with respiration, & can’t see normal rib
shadow above them)
! Not all rockets = fluid
! widespread pneumonia
! widespread fibrosis
! rockets can be normal in lowest intercostal space
! Posterior lung rockets can be normal in supine
patients
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72. Lung sliding
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73. Lung sliding
! Visceral pleura glides on parietal pleura
! Why is it important?
! A lines + sliding = dry lung = A profile
! A lines without sliding = PTX = A’ profile
! Rockets + sliding = APO = B profile
! Rockets without sliding = ARDS / pneumonia
= B’ profile
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74. Lots of things can prevent
lung sliding
! CAL
! Apices
! Failure to ventilate
! eg R main stem intubation (L lung doesn’t
move)
! Eg pain (chest splinting)
! Pneumothorax
! Pneumonia & ARDS
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75. Lots of things can prevent
lung sliding
! CAL
! Apices
! Failure to ventilate
! eg R main stem intubation (L lung doesn’t
move)
! Eg pain (chest splinting)
! Pneumothorax
! Pneumonia & ARDS … ???
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76. How the hell do pneumonia /
ARDS reduce lung sliding?
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77. Here’s how:
ARDS/ disseminated APO:
pneumonia: Transudate
Exudate Lung sliding is
Proteinaceous preserved, smooth
‘sticky’ pleural line
Reduced / absent lung B profile
sliding, irregular
pleural line
B’ profile

78. Is sliding preserved?

79. Is sliding preserved?

80. Is sliding preserved?

81. Is sliding preserved?

82. Is sliding preserved?

83. So how do I diagnose PTX?
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84. Diagnosis of PTX
1. No lung sliding
2. No B lines
3. Ideally, a lung point
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85. 1. a o lung sliding
N
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86. Which side is the PTX?

87. Which side is the PTX?

88. Which side is the PTX?

89. Tip 1: compare sides
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90. Tip 1: compare sides
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91. Tip 1: compare sides
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92. Tip 2: M-mode can help
! Sliding = seashore sign
! No sliding = stratosphere sign
! But beware ‘false seashore’ with chest
wall movement!
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93. Normal: seashore sign
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94. PTX: stratosphere sign
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95. Stratosphere sign
! M-mode = motion mode
! If something isn’t moving, it’s a
straight line
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96. 2. No B lines
• i.e. the A’ profile (air is dry)
• Even a single B line rules out PTX
• Because B lines = air/fluid interface
• Absent sliding + B line = LUNG
• EG not ventilating
• EG pneumonia
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97. 3. The lung point sign
! Specific to PTX
! the site where normal lung gives way to PTX
! on one side of the image sliding is present
! on the other side it is absent.
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98. Lung point sign
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99. What if there’s no lung point sign?
there might still be a massive PTX which has
collapsed the entire lung. Go back to the
clinical picture & decide whether you need
to go ahead & decompress the chest.
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100. Can I trust lung US for PTX?
If you are just starting out:
! If you want to find all PTX: get a CT
! Stable patient, Negative CXR, positive
EFAST: get a CT … or ask a friend to scan
! Unstable patient, Negative CXR, positive
EFAST: decompress the chest
! Rushing to OT/ chopper, neg CXR, pos
EFAST: warn anaesthetist or insert ICC
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101. Test
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102. Sliding or not?
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103. Sliding or not?
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104. Sliding or not?
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105. Sliding or not?
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106. Consolidation
a.k.a. the C profile
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107. Alveolar consolidation
! If you can see lung tissue, it ain’t normal!
! It ain’t aerated
! Collapse
! Consolidation
! Atelectasis
! Contusion
! Infarction (PE)
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108. Alveolar consolidation
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109. Putting it all together
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110. Terminology
• A profile = A lines (or no lines), sliding preserved
• A’ profile = A lines (or no lines), sliding absent
• B profile = lung rockets in all windows, sliding
preserved
• B’ profile = lung rockets in all windows, sliding
reduced / absent
• A/B profile = patchy rockets alternate with normal
areas
• C profile = areas of consolidation
• PLAPS positive = consolidation / effusion at bases
• PLAPS negative = anything else at bases (A lines /
B lines / rockets)

111. A word of advice about the A profile
• All A lines = A profile
• No lines seen? Still = A profile
• Up to 2 B lines per window are OK! Still = A profile
• Z lines? Still = A profile

112. Test
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113. A, A’, B, B’ or C?

114. A, A’, B, B’ or C?

115. A, A’, B, B’ or C?

116. A, A’, B, B’ or C?

117. A, A’, B, B’ or C?

118. A, A’, B, B’ or C?

119. A, A’, B, B’ or C?

120. A, A’, B, B’ or C?

121. A, A’, B, B’ or C?

122. A, A’, B, B’ or C?

123. A, A’, B, B’ or C?

124. A, A’, B, B’ or C?

125. A, A’, B, B’ or C? (NB trick question)

126. A, A’, B, B’ or C? (NB trick question)

127. PLAPS: positive or negative?

128. PLAPS: positive or negative?

129. PLAPS: positive or negative?

130. PLAPS: positive or negative?

131. PLAPS: positive or negative?

132. PLAPS: positive or negative?

133. Normal lungs
• A profile
• Up to 2 B lines per window are OK
• PLAPS negative

134. Pneumothorax
• A’ profile = A lines (or no lines), sliding absent
• There are no B lines at all on that side
• There will be a lung point unless lung is completely
collapsed

135. Acute cardiogenic pulmonary oedema
(APO)
• B profile =
• lung rockets in all windows
• lung sliding preserved

136. ARDS or pneumonia
B’ profile =
• lung rockets in all windows
• lung sliding reduced / absent
• And pleural line may be irregular
A/B profile
C profile
A profile anteriorly, PLAPS positive

137. Pulmonary embolus
A profile anteriorly, PLAPS positive or negative i.e.
lungs can look normal
Sometimes C profile (pulmonary infarcts)

138. Asthma / COPD lungs look ‘normal’
• A profile
• PLAPS negative

139. Sticking needles in thorax
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6

140. Chest drains/
thoracocentesis
! Same rationale as central line placement
! Ensures you don’t stick ICC in the liver
! Tricks:
! Get patient to take maximal inspiration &
expiration
! Scan in 2 planes
! Scan in same position you’ll insert ICC
! Use real time US
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141. Let’s wrap this up
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142. Lung US: top tips
! Curved probe / FAST preset
! At right angles to the ribs
! Is there sliding? Tip: compare sides
! A or B or C?
! PLAPS or no PLAPS?
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143. Any questions?