1. Lung Ultrasound
Part 1
Drew Sheldon, MD

2. Objectives Know the basic principles of lung ultrasound
Learn the steps of how to perform a bedside lung ultrasound
Learn the 2 images of a normal lung ultrasound scan

3. Lung Ultrasound Principles
Why use lung ultrasound?
Quick
Reproducible
Safe
Effective
Easy to learn
Faster than a CXR
Findings can be re-demonstrated in real time
No radiation or harm to the patient
Able to differentiate between multiple diagnoses
Only 5 artifacts to know
Effectiveness:
Using Bedside Lung Ultrasound in Emergency (BLUE) protocol (Lichtenstein 2008) yielded dx in 90.5% of cases of acute respiratory distress
PTX: CXR Sn 27-82%, Sp % vs US Sn 85-89%, Sp %, LR
Pleural Effusions: US Sn 84%, Sp 100%, accuracy 94%
Alveolar Consolidation: US Sn & Sp >90%

4. Lung Ultrasound Principles
Unlike other ultrasound scans, lung ultrasound relies on artifacts
Air refracts ultrasound which makes it bright white (hyperechoic) on scans
Fluid conducts ultrasound easily which makes it black (hypoechoic) on scans
Specific interactions of air and fluid create reproducible artifacts
Gravity influences the location of these artifacts
Remember US is refracted by air (or bounces off of it and does not go through it) = white or “hyperechoic”
US goes through water and fluids easily = black or “hypoechoic”
Artifacts in lung ultrasound are helpful unlike other scans; eg: cardiac US, abdominal US, FAST scan
Lichtenstein. Lung ultrasound in the critically ill. Annals of Intensive Care :1

5. Lung Ultrasound Principles
All artifacts and signs arise from the pleural line
Almost all lung pathology meets the pleural line
Therefore patterns of artifacts can be applied to clinical decision making
Remember US is refracted by air (or bounces off of it and does not go through it) = white or “hyperechoic”
US goes through water and fluids easily = black or “hypoechoic”
Artifacts in lung ultrasound are helpful unlike other scans; eg: cardiac US, abdominal US, FAST scan
Lichtenstein. Lung ultrasound in the critically ill. Annals of Intensive Care :1

6. Performing a Lung Ultrasound
Probe Choice
#1 Phased Array: better depth, able to visualize all artifacts
#2 Linear Transducer: sacrifices depth for resolution, used to clarify lung sliding #2 #1

7. Performing a Lung Ultrasound
Probe in sagittal or vertical axis
3 Standard Zones
Anterior Zone
Indicator to head
(Make sure dot is on the
left side of the screen)
Lateral Zone
Posterior Zone or PLAPS Point
Anatomical Spots: (for reference, but don’t need to know specifics)
Anterior Zone: Mid-Clavicular Line 2nd-3rd Intercostal Space
Lateral Zone: Lateral-Clavicular Line 4-5th Intercostal Space
Posterior Zone or PLAPS Point (Posterior-Lateral Alveolar/Pleural Syndrome)*
Right Mid-Axillary Line 9-10th Intercostal Space
Left Posterior Axillary Line 7-8th Intercostal Space
*From the BLUE (Basic Lung Ultrasonography in Emergency) protocol, coined by Dr. Lichtenstein in 2008
(CHEST 2008; 134:117–125)
(Posterior Lateral Alveolar Pleural Syndrome)

8. Performing a Lung Ultrasound
Anterior Zone
PLAPS Point
Lateral Zone
Another way to determine probe positions (redundant)
Anterior and Lateral Zones
Posterior Zone or PLAPS Point

9. Normal Lung Ultrasound Images
Anterior and Lateral Zones
Normal lung with air refraction
Both zones should look the same
Posterior Zone or “PLAPS” Point
Should see air refraction from normal lung hiding the liver or spleen on inspiration
Lung
Liver (or spleen)
Lung
Diaphragm

10. Normal Lung Ultrasound Images
Anterior Zone
Rib
Lateral Zone
Lung
(probe)

11. Normal Lung Ultrasound Images
PLAPS Point
Lung
(Make sure dot is on the
left side of the screen)
Liver (or spleen)
(left decubitus)
(probe)
Diaphragm

12. Summary
Lung ultrasound is a quick, safe, and effective imaging modality
Lung ultrasound relies on artifacts which are generated by air, fluid, and their interactions; these can be used to guide clinical management
There are three standard scanning zones in bedside lung ultrasound: Anterior Zone, Lateral Zone, and Posterior Zone or PLAPS Point
There are 2 basic images to know in a normal lung ultrasound scan