Lung Ultrasound 2

This station covers Lung Ultrasound Pathology. A snapshot of the evidence is shown below.

Image From Marini et al. Lung Ultrasound: The Essentials. Radiology RSNA 2021

A. Pneumothorax

  • Linear High Frequency Probe
  • Scan anteriorly in the supine patient
  • Absent lung sliding is seen
  • Absent lung sliding is NOT diagnostic of pneumothorax as it can be seen in obstructive atelectasis, apnea, endobronchial intubation and emphysematous bullae
  • Look for a LUNG POINT to confirm pneumothorax
  • Linear High Frequency Probe
  • Lung sliding is present on the left of the display
  • Lung sliding is absent on the right of the display
  • This is called a lung point
  • Lung sliding is absent when the parietal and visceral pleura are separated.
  • Linear High Frequency Probe
  • Absent lung sliding on the left of the display
  • Lung sliding is present on the right of the display
  • Schematic approach to diagnosis of pneumothorax with lung ultrasound.
  • Step 1: Supine Patient
  • Step 2: High frequency linear probe: transducer of choice
  • Step 3: Image – Use general/radiology convention
  • Step 4: Interpretation – pleural line, lung sliding ? lung pulse ? A-lines/B-Lines ? Lung Point ?

B. Pleural Effusion

  • Lung scan is performed with a curvilinear probe
  • The display marker follows general/radiology convention and is on the left of the display
  • The liver and diaphragm are seen. There is a large aneschoic area cephalad to the diaphragm. The spine is clearly seen in the presence of a pleural effusion.
  • Lung scan is performed with a curvilinear probe
  • Anechoic spaces are seen above and below the diaphragm. The diaphragmatic movement is seen clearly
  • This represents pleural fluid and intra-abdominal fluid.

C. Subpleural Consolidation

  • High Frequency Linear Probe
  • Lung sliding is seen
  • The pleura appears irregular and there is a small circular anechoic area just below the pleural line
  • B-lines extend downwards from this anechoic area
  • This represents an area of subpleural consolidation

D. Consolidation

  • Curvilinear Probe
  • The lung appears solid and fluid filled
  • There are multiple echogenic bright areas likely representing fluid filled bronchi
  • Which probe is being used here?
  • Describe the lung ultrasound findings.
  • The shred sign and tissue sign are seen here
  • The shred sign represents the jagged edge between normal lung and consolidated lung.
  • The consolidated area appears tissue like with multiple bright spots within it. These are fluid filled brochi. 

E. Alveolar Fluid / Pulmonary Oedema

From left to right, there are increasing B-lines seen, representing worsening pulmonary/interstitial fluid
  • Curviliear low frequency probe
  • B-Lines are seen
  • B-lines are vertical echobright linear lines that start at the pleural surface and extend all the way down to the end of the image display
  • They can be present in normal lung, but at less than 3 B-lines per intercostal space
  • As the ammount of alveolar fluid increases, the B-lines begin to coalesce
  • B-lines will obliterate A-lines