Ultrasonography is a useful tool for evaluating the chest that does not use ionizing radiation. It can be used to assess the pleura, chest wall, and lung parenchyma. A linear high frequency transducer is best for superficial structures while a lower frequency convex probe provides better penetration for deeper assessment of the lungs. Normal lung appears as a bright pleural line with horizontal A-lines, while various artifacts and patterns of B-lines can indicate pathological lung conditions. Doppler ultrasonography can also provide blood flow information about lung lesions.

2. Basics of Chest Sonography
and Anatomy of Chest Wall
By
Gamal Rabie Agmy , MD , FCCP
Professor of Chest Diseases ,Assiut
University

4. • U/S probes emit and
receive the energy as
waves to form pictures

5. Ultrasound Transducer
Speaker
transmits sound pulses
Microphone
receives echoes
• Acts as both speaker & microphone
Emits very short sound pulse
Listens a very long time for returning echoes
• Can only do one at a time

6. • Diagnostic ultrasonography
is the only clinical imaging
technology currently in use
that does not depend on
electromagnetic radiation.

7. • Immediate bedside availability
• Immediate bedside repeatability
• Rapid goal directed application
• Cost saving
• Reduction in radiation exposure
Advantages of Transthoracic
Ultrasonography

8. Physical Principles

9. Cycle
• 1 Cycle = 1 repetitive periodic oscillation
Cycle

10. Frequency
• # of cycles per second
• Measured in Hertz (Hz)
-Human Hearing 20 - 20,000 Hz
-Ultrasound > 20,000 Hz
-Diagnostic Ultrasound 2.5 to 10
MHz
(this is what we use!)

11. frequency
1 cycle in 1 second = 1Hz
1 second
= 1 Hertz

12. High Frequency
• High frequency (5-10 MHz)
greater resolution
less penetration
• Shallow structures

13. Low Frequency
• Low frequency (2-3.5 MHz)
greater penetration
less resolution
• Deep structures

14. Probes

15. Wavelength
• The length of one complete cycle
• A measurable distance

16. Wavelength
Wavelength

17. Amplitude
• The degree of variance from the normal
Amplitude

18. The Machine

19. Ultrasound scanners
• Anatomy of a scanner:
– Transmitter
– Transducer
– Receiver
– Processor
– Display
– Storage

20. Changing the TGC

21. Changing the Gain

22. Displays
• B-mode
– Real time gray scale, 2D
– Flip book- 15-60 images per second
• M-mode
– Echo amplitude and position of moving
targets
– Valves, vessels, chambers

23. “B” Mode

24. “M” Mode

25. A common language: Color Coding
Black Grey White

26. Image properties
• Echogenicity- amount of energy
reflected back from tissue interface
– Hyperechoic - greatest intensity - white
– Anechoic - no signal - black
– Hypoechoic – Intermediate - shades of
gray

27. Hyperechoic
Hypoechoic
Anechoic

28. Ultrasound Artifacts
• Can be falsely interpreted as real
pathology
• May obscure pathology
• Important to understand and appreciate

29. Ultrasound Artifacts
• Acoustic enhancement
• Acoustic shadowing
• Lateral cystic shadowing (edge artifact)
• Wide beam artifact
• Side lobe artifact
• Reverberation artifact
• Gain artifact
• Contact artifact

30. Acoustic Enhancement
• Opposite of acoustic shadowing
• Better ultrasound transmission allows
enhancement of the ultrasound signal
distal to that region

31. Acoustic Enhancement

32. Acoustic Shadowing
• Occurs distal to any highly reflective or
highly attenuating surface
• Important diagnostic clue seen in a
large number of medical conditions
– Biliary stones
– Renal stones
– Tissue calcifications

33. Acoustic Shadowing
• Shadow may be more prominent than
the object causing it
• Failure to visualize the source of a
shadow is usually caused by the object
being outside the plane of the
ultrasound beam

34. Acoustic Shadowing

35. Acoustic Shadowing

36. Lateral Cystic Shadowing
• A type of refraction artifact
• Can be falsely interpreted as an
acoustic shadow (similar to gallstone)

37. X
Lateral Cystic Shadowing

38. Beam-Width Artifact
• Gas bubbles in the duodenum can
simulate a gall stone
• Does not assume a dependent posture
• Do not conform precisely to the walls of
the gallbladder

39. Beam-Width Artifact
Beam-width artifact
Gas in the duodenum
simulating stones

40. Side Lobe Artifact
• More than one ultrasound beam is
generated at the transducer head
• The beams other than the central axis
beam are referred to as side lobes
• Side lobes are of low intensity

41. Side Lobe Artifact
• Occasionally cause
artifacts
• The artifact by be
obviated by
alternating the angle
of the transducer
head

42. Side Lobe Artifact

43. Reverberation Artifacts
• Several types
• Caused by the echo bouncing back and
forth between two or more highly
reflective surfaces

44. Reverberation Artifacts
• On the monitor parallel bands of
reverberation echoes are seen
• This causes a “comet-tail” pattern
• Common reflective layers
– Abdominal wall
– Foreign bodies
– Gas

45. Reverberation Artifacts

46. Reverberation Artifacts

47. Gain Artifact

48. Contact artifact
• Caused by poor probe-
patient interface

49. Mirror Artifact

51. Traditionally, air has been considered the
enemy of ultrasound and the lung has been
considered an organ not amenable to
ultrasonographic examination. Visualizing the
lung is essential to treating patients who are
critically ill.

55. Lines written on ultrasound in the five
Light‟s editions
43
78
102
122
278
1983 1990 1995 2001 2008

56. 1998 -2008

57. 2009

58. 2010
V SCAN

59. Probes

60. A high-resolution linear transducer of 5–10 MHz is
suitable for imaging the thorax wall and the
parietal pleura (Mathis 2004). More recently
introduced probes of 10–13 MHz are excellent for
evaluating lymph nodes (Gritzmann 2005), pleura
and the surface of the lung.
For investigation of the lung a convex or sector probe
of 3–5 MHz provides adequate depth of penetration.

61. Transthoracic Sonography

63. Lungs –normal static findings
Normal lung considered “invisible” to
ultrasonographer
Artefactscan be used to infer normality or
abnormality
A lines
horizontal reverberation artifacts from pleural
line
the only finding in 2/3 of normal lung US
B lines
vertical narrow bands from pleural line to edge
of screen
obliterate the A linme
Multiple B lines = Ultrasound Lung Rockets =
Abnormal lung has characteristics that are
clinically useful

64. Lungs –normal dynamic findings
Pleural sliding (lung sliding sign)
Pleural line “shimmers” with respiration
Presence of lung sliding rules out pneumothorax
Lung sliding greatest in lower thorax (greatest
expansion)
Absence of lung sliding has a number of causes
Pneumothorax
Apnoea
Pleural adhesions
Mainstembronchial intubation or occlusion
Critical parenchymal lung disease e.g. ARDS,
contusion

65. Scanning Positions for
Chest Sonography

69. Focused exam – 8 views
Sagittal or coronal views
RIB SHADOWS confirm
position and guide you to
pleura.

71. The Regions
1 2
3
4
Volpicelli et al, Am J Emerg Med 2006; 24: 689-696
Region 2 is usually above the nipple

72. THE BAT VIEW
Chest wall
Pleural line

73. Rock the probe slightly side to side
until the pleura is in sharp focus
Pleura not at right angles
to probe so indistinct
Correct angle =
sharpest edge.

74. Interpretation

75. Normal lung surface
Left panel: Pleural line and A line (real-time).
The pleural line is located 0.5 cm below the rib line in the adult.
Its visible length between two ribs in the longitudinal scan is
approximately 2 cm. The upper rib, pleural line, and lower rib (vertical
arrows) outline a characteristicpattern called the bat sign.

77. A lines = default normal
 Horizontal echo
reflection at exact
multiples of intervals
from surface to
bright reflector.
 Dry lung OR PNTX
 Decay with depth
 Obliterated by B
pleura A
A
A
A
A
A

79. B lines = fluid in alveolus or
interstitium
 Originates from
pleural line
 Reaches base of
screen OR ALMOST
 MORE THAN 2 at
once is abnormal
EXCEPT in lung base
Remember as
„Kerley Bs‟
Not exactly the
same.
RIB
RIB
B B B BB

80. B Lines = Crackles

81. Confluent B lines = Bad Bad
 „White‟ or „shining‟
lung
 Means increased
severity
 Probably indicates
thicker fluid in alveoli
eg protein or
inflammatory cells
 % space / 10

82. B x 3 x 2 x 2 = CCF
Makes assumption that „globally‟ wet
lungs are most likely to be CCF
12

85. the "seashore sign" (Fig.3).

87. Normal Anatomy

88. Normal lung surface
Left panel: Pleural line and A line (real-time).
The pleural line is located 0.5 cm below the rib line in the adult.
Its visible length between two ribs in the longitudinal scan is
approximately 2 cm. The upper rib, pleural line, and lower rib (vertical
arrows) outline a characteristicpattern called the bat sign.

90. Normal Chest Ultrasound
Superficial tissues
ribs
Posterioracousticshadowing
Impureacousticshadowing
Pleuralline
Muscle
Fat
Pleura
Lung

98. HEPATISATION VS COLLAPSE
SOLID, NO CHANGE WITH
RESPIRATION
COLLAPSE – CONCAVE EDGES,
CHANGE WITH RESPIRATION

101. the "seashore sign" (Fig.3).

109. Duplex Doppler sonogram of a 5 x 3 cm hypoechoic mass
(adenocarcinoma) in upper lobe of left lung shows blood flow
at margin of tumor near pleura. Spectral waveform reveals
arteriovenous shunting: low-impedance flow with high
systolic and diastolic velocities. Pulsatility index = 0.90,
resistive index = 0.51, peak systolic velocity = 0.47 m/sec, end
diastolic velocity =0.23 m/sec, peak frequency shift = 3.8 kHz,

110. Duplex Doppler sonogram in 67-year-old man with pulmonary
tuberculosis in lower lobe of left lung shows several blue and
red flow signals in massiike lesion. Spectral waveform reveals
high-impedance flow. Pulsetility index = 4.20, resistive index =
0.93, peak systolic velocity = 0.45 m/sec, end diastolic
velocity = 0.03 m/sec, Doppler angle = 21#{

111. Alveolar-interstitial
syndrome

121. Duplex Doppler sonogram of a 5 x 3 cm hypoechoic mass
(adenocarcinoma) in upper lobe of left lung shows blood flow
at margin of tumor near pleura. Spectral waveform reveals
arteriovenous shunting: low-impedance flow with high
systolic and diastolic velocities. Pulsatility index = 0.90,
resistive index = 0.51, peak systolic velocity = 0.47 m/sec, end
diastolic velocity =0.23 m/sec, peak frequency shift = 3.8 kHz,

122. Duplex Doppler sonogram in 67-year-old man with pulmonary
tuberculosis in lower lobe of left lung shows several blue and
red flow signals in massiike lesion. Spectral waveform reveals
high-impedance flow. Pulsetility index = 4.20, resistive index =
0.93, peak systolic velocity = 0.45 m/sec, end diastolic
velocity = 0.03 m/sec, Doppler angle = 21#{

126. (Chest. 2008; 133:836-837)
© 2008 American College of Chest
Physicians
Ultrasound: The Pulmonologist’s New
Best Friend
Momen M. Wahidi, MD, FCCP
Durham, NC
Director, Interventional Pulmonology, Duke
University Medical Center, Box 3683,
Durham, NC 27710