Pulmonary POCUS

Lungs R’ U/S

Pulmonary or Thoracic POCUS involves 4 basic areas to image. These are the symmetrical halves of the anterior chest, and each hemidiaphragm. Like Cardiac POCUS, complete examinations include many other variations of these views and fancier things such as ‘M’ mode & Doppler.

The pulmonary POCUS exam can be split up in multiple ways. The most common ways used to think about the lung fields are the 8 view, and 4 view methods:

Remember, when placing your probe on the patient, you want to keep your marker aimed at either the patient’s head, or the right side of their body, depending on what type of cross-section you’re trying to view. For example, for the 4 view method:

Now, let’s talk about what normal, and what we’re looking for at each site.

Anterior Lung Fields

These correspond to 1 & 2 on the 4-view method; 1-4 & 6-7 on the 8-view method.

Clinical questions:
Is there a pneumothorax?
Is there evidence of pneumonia?
Is there evidence of pulmonary edema or another diffuse alveolar syndrome?

Probe Positioning
Use the linear probe to assess for pneumothorax.
Use the phase-array or curvilinear probe otherwise.
It’s often easier to aim the marker towards the patient’s right side, given the limited space between ribs, however you can aim it towards the patient’s head too.

Normal Anatomy

Above you can see horizontal “A” lines, which are reflections of the pleura. These are normal, and represent ‘dry’ interlobular septa.

On the other hand, “B” lines are vertical, and almost look like spotlights coming down from the pleura. Up to 2 of these in an intercostal space are normal, but more than that is consistent with pulmonary edema or a consolidative process.

Special: M Mode for Lung Slide

Left: Normal “Seashore sign”. Right: Pneumothorax “Barcode/Stratosphere sign”

When the parietal and visceral pleura oppose one another, lung sliding leads to dynamic motion below the parietal pleura. This is because the lung itself is able to move independently from the chest wall. This causes the appearance of a sandy beach, and ocean: the “Seashore sign”.
When there is pneumothorax, motion below the parietal pleura is static, and mirrors motion above the parietal pleura. It indicates chest wall motion only, as there is no independent movement of the lung. This appears more like a barcode, or straight jetstreams: the “Barcode” or “Stratosphere sign”.

Right Hemidiaphragm

These correspond to 5 on the 8-view method; 3 on the 4-view method.

Clinical questions:
Is there a pleural effusion?
Is there a lower lobe pneumonia?
For other clinical questions related to the Abdomen, click *here*

Probe Positioning
Use the phase array or curvilinear probe (unless looking for pneumothorax).
Start at the mix-axillary line, looking for the hyperechoic diaphragm.
Aim the marker towards the patient’s head.

Normal Anatomy

You can see the “Lung Curtain” overcome the liver when the patient inhales deeply. This is because normal aerated lung is full of air, which appears ‘hazy’. If you look closely you can see “A lines” come into view as this occurs.

Left Hemidiaphragm

These correspond to 8 on the 8-view method; 4 on the 4-view method.

Clinical questions (similar to R Hemidiaphragm):
Is there a pleural effusion?
Is there a lower lobe pneumonia?
For other clinical questions related to the Abdomen, click *here*

Probe Positioning
Use the phase array or curvilinear probe (unless looking for pneumothorax).
Start at the mix-axillary line, looking for the hyperechoic diaphragm.
Aim the marker towards the patient’s head.

Normal Anatomy

From a lung perspective this is similar to the Right Hemidiaphragm, you expect to see no free fluid in any of the spaces between organs, or above the diaphragm, with that same “Lung Curtain” when the lung parenchyma comes into view.

Posterior Lung Fields

This is more commonly used when looking for targets for thoracentesis in a patient who is able to sit (or stand) upright.

Again, we’ll aim our probe markers towards the patient’s head. Remember, the scapula is bone and won’t allow ultrasound waves to pass through it. Because fluid is dependent (unless it’s loculated), starting inferiorly and working your way up is usually the best way to find your target.

Clinical questions:
Is there a pleural effusion target for thoracentesis?

Probe Positioning
Use the phase array or curvilinear probe.
Start near midline, inferiorly, and move superiorly looking for the hyperechoic diaphragm. For loculated effusions, use adjunct imaging (CXR or CT scan) to help you identify where to start looking.
Again, aim the marker towards the patient’s head.

Normal Anatomy (same as Anterior Lung Fields)

That’s it! You made it through!
Now go out there and TRY IT!!