Lung Ultrasound Pitfalls

US lung consolidation TsungThoracic sonography is one of the most rapidly growing areas of emergency and critical care ultrasound. One very important emerging indication is to assess for lung consolidation. The characteristic appearance of consolidated lung is very sensitive and specific for pneumonia, but novices should heed some important pitfalls in making the diagnosis.

Special thanks to Jim Tsung, MD, MPH and Brittany Jones, MD for their tips, videos, and ongoing research in this important field! For further reading on this topic, please see this article.

Pitfall #1 – confusing thymus for a consolidation

Normal thymus in sagittal view:

Thymus (top half of screen) and heart (bottom right). Don’t confuse thymus for lung consolidation. Note there are no air bronchograms, but thymus has a faint speckled appearance.

Normal thymus in transverse view:

Thymus (top half of screen) and heart (bottom right). Don’t confuse thymus for lung consolidation. Note there are no air bronchograms, but thymus has a faint speckled appearance
Pneumonia adjacent to Thymus in transverse view:

Lung consolidation with air bronchograms (top left) adjacent to normal thymus (speckled appearance on top right) with heart (bottom right)

Pitfall #2 – mistaking spleen for consolidation.

This is an important pitfall for everyone to know about. The same issue applies to the liver & stomach. The sensitivity of lung US for pneumonia rises >90% if this mistake is avoided.

Left lower chest- sagittal view:

Be careful scanning the left lower chest (left anterior and left axillary line) – air in stomach and spleen may look like pneumonia if you don’t realize that you have scanned inferior to the diaphragm and past the end of the pleural line. Most common error by novices.

Left lower chest- transverse view:

Be careful scanning the left lower chest (left anterior and left axillary line) – air in stomach and spleen may look like pneumonia if you don’t realize that you have scanned inferior to the diaphragm and past the end of the pleural line.

Pitfall #3- missing pleural effusion

Here are a few examples to refresh your memory.

Left pleural effusion:

Identify:

  • Pleural effusion (anechoic wedge just beneath ribs and pleura)
  • Lung
  • Diaphragm
  • Spleen
  • Air in stomach

Do not confuse spleen and air in stomach for pneumonia.

Right pleural effusion:

Identify:

  • Pleural effusion
  • Lung
  • Diaphragm
  • Liver