CXR Pathology Flashcards
What causes lobar collapse? Give some examples
Obstruction of the lobar bronchus
Examples include: tumours, aspirated foodstuffs, mucus impaction
What happens to the adjacent major fissure of a collapsed lung lobe?
It is dragged out of place
What would you expect to see in a left lower lobe collpase?
- Left volume loss
- Increased density in left retrocardiac region
- Left hilum displaced downward
- Loss of clarity of medial left hemidaiphragm
What would you expect to see in a left upper lobe collapse?
- “veil-like opacity” - diffuse opacification of the left hemithorax
- loss of heart shadow clarity
What would you expect to see in a right upper lobe collapse?
- loss of clarity of upper right mediastinum
- right upper zone density increase
- Elevation of horizontal fissure
Why do right middle and lower lobe collapse tend to occur together/not in isolation?
Both are supplied by the intermediate bronchus so occlusion to this would cause a collapse in both lobes
What would you expect to see in a right middle and lower lobe collapse?
- Loss of clarity of right hemidiaphragm and right heart border
- Density in right lower zone, depression of horizontal fissure and oblique fissure
How can pulmonary consolidation and collapse be easily differentiated?
Consolidation has no volume loss, collapse does.
What does infection of the lingula do to the left heart border on CXR?
Causes the left heart border to become obscured
In what situations is the pleural cavity visible on CXR?
pneumothorax or pleural effusion
What does a small pneumothorax look like on CXR and where is it often found?
Looks like a dark cresent without lung markings bound medially by the lung edge. It is often seen in the lung apex
What does a large pneumothorax look like?
Should be able to make out a black air-filled pleural space with no lung markings, and should be able to see the lung edge
What does a tension pneumothorax look like?
Essentially a large pneumothorax that is displacing the mediastinum - look for tracheal deviation. Collapsed lung may be squashed against the heart making lung border difficult to see
What are CXR signs of pulmonary oedma?
- Dilation of upper lobe vessels and cardiomegaly
- Interstitial opacities (kerley B lines)
- Airspace opacification (filling of alveoli with fluid, when acute and severe has a ‘batwing’ distribution)
- Pleural effusion
ABCDE mnemonic
What is the ABCDE mnemonic for pulmonary oedma?
A - alveolar oedma (bat wing opacities)
B - kerley B lines
C - cardiomegaly
D - dilated upper lobe vessels
E - effusion
What would be expcted on a CXR for a correctly placed endotracheal tube?
- Tip 5cm above carina
- width 2/3 diameter of trachea
- cuff should not expand the trachea
What may be seen in a malpositioned ET tube?
- tip may extend past carina
- tip is often in the right main bronchus
- may have entered the oesophagus
What is the ideal position for a nasogastric tube?
- subdiaphragmatic position in the stomach
- Overlying gastric bubble
- Ideally, at least 10cm beyond the gasto-oesophageal junction
How are NG tubes commonly malpositioned?
- remain in the oesophagus
- coiled in upper airway
- traversing into bronchus or lung
- intracranial in pateint with skull trauma/surgery
