Ultrasound - Pleural Space
Case Study 1
TITLE - HAEMOTHORAX
HISTORY
2 patients present to the ED following penetrating trauma to the chest.
ULTRASOUND FINDINGS
The videos show:
1. Hypoechoic fluid in the pleural space, which likely represents fresh blood from trauma
2. Echogenic material in the pleural space, which likely represents clotted blood from trauma
DISCUSSION
Fresh blood in the pleural space will be seen as hypoechoic fluid in the dependent areas of the thoracic cavity. It is difficult to differentiate a fresh haemothorax from other causes of pleural effusions. With older haemothoraces, blood may have clotted. Clotted blood has an echogenic appearance on ultrasound, and may sometimes appear similar to parenchymal tissue.
Video of clotted haemothorax courtesy of Dr Darmas Hardjo-Soekatmo.
Prepared by Ahilan Parameswaran and Justin Bowra, SAH
Videos
Pleural Fluid - Clotted Blood from ACI on Vimeo.
Case Study 2
TITLE - PNEUMOTHORAX - A LINES
HISTORY
A middle aged woman presents with breathlessness and pleuritic chest pain.
ULTRASOUND FINDINGS
The still images show A-lines in both lung fields. The pneumothorax (PTX) image demonstrates considerably more ‘A lines’ (note that some are in fact appear to be reflections from the fascial layer between the intercostal muscles, rather than reflections from the pleural line itself).
A video loop or M-mode images will be required to determine whether a pneumothorax is present.
DISCUSSION
Regularly spaced, hyperechoic reverberation artifacts are formed when sound waves strike very reflective surfaces (such as metal) or encounter scatter from air. In lung imaging they are termed A lines and are reverberation artifacts of the pleural line.
It is important to note that they may be present in normal, dry lung (due to air-filled lung tissue) and in pneumothoraces (due to air in the pleural space). They may be more prominent in a pneumothorax, such as in this case, as air in the pleural space is less humidified. However, this is not sufficient to diagnose a pneumothorax and the presence or absence of lung sliding should be sought.
Prepared by Ahilan Parameswaran and Justin Bowra, SAH
Images
Videos
Case Study 3
TITLE - PNEUMOTHORAX - PRE AND POST DRAINAGE
HISTORY
A young man presented with pleuritic chest pain. A chest drain was inserted as treatment.
ULTRASOUND FINDINGS
Ultrasound of the lung demonstrates absent lung sliding, consistent with pneumothorax. A subsequent ultrasound post drain insertion demonstrates lung sliding, consistent with successful drainage of the pneumothorax.
DISCUSSION
Ultrasound diagnosis of pneumothorax is dependent on the finding of absent pleural sliding, caused by air in the pleural space impeding the transmission of sound waves. Following treatment, pleural sliding can be visualised, as the intervening air has been removed.
Prepared by Ahilan Parameswaran and Justin Bowra, SAH
Videos
Pneumothorax - Pre Drainage from ACI on Vimeo.
Pneumothorax - Post Drainage from ACI on Vimeo.
Case Study 4
TITLE - SMALL LEFT PNEUMOTHORAX
HISTORY
A young man presents following trauma to the chest.
ULTRASOUND FINDINGS
Ultrasound of the lung demonstrates absent lung sliding on one side (with lung point), consistent with a pneumothorax.
DISCUSSION
Ultrasound diagnosis of pneumothorax is dependent on the finding of absent pleural sliding, caused by air in the pleural space impeding the transmission of sound waves. This may be visualised on M-mode as the ‘stratosphere’ sign. Normal lung sliding is seen as the ‘seashore’ sign on M-mode. However, breath holding and hypoventilation can act as potential mimics for a pneumothorax due to decreased lung movement.
One finding that assists in differentiating PTX from hypoventilation is the ‘lung pulse’, which are the transmitted pulsations of the patient’s heartbeat, seen here as intermittent movement on both 2D and M-mode images.
Prepared by Ahilan Parameswaran and Justin Bowra, SAH
Images
Normal Lung Seashore sign
Pneumothorax stratosphere sign
Videos
No Pneumothorax (Normal Right Lung) – Lung Sliding 2 from ACI on Vimeo.
Pneumothorax (Left Lung) – Absent Lung Sliding from ACI on Vimeo.
Pneumothorax (Left Lung) – Absent Lung Sliding 2 from ACI on Vimeo.
Case Study 5
TITLE - PNEUMOTHORAX (SMALL)
HISTORY
A young man presents with pleuritic chest pain.
ULTRASOUND FINDINGS
Ultrasound of the lung demonstrates a lung point, consistent with a small pneumothorax.
DISCUSSION
A lung point represents the transition from pneumothorax to normal lung, found in the highest point on the chest wall, and can be a specific sign for ultrasound diagnosis of pneumothorax. Small pneumothoraces, as in this case, are best visualised with a high-frequency probe such as the linear probe, and may be missed with low frequency probes (curved or sector).
Note that the lung point is not seen when scanning large pneumothoraces (PTX), because the lung has collapsed beneath the PTX itself and therefore no lung abuts the chest wall.
Prepared by Ahilan Parameswaran and Justin Bowra, SAH
Videos
Tiny Pneumothorax - Lung Point - Sector Probe from ACI on Vimeo.
Tiny Pneumothorax - Lung Point from ACI on Vimeo.
Tiny Pneumothorax - Lung Point 2 from ACI on Vimeo.