19) Chest X-Ray Flashcards
What is a radiograph?
Photographic image of internal composition of body, produced by X-rays being passed through the body part and being absorbed to different degrees by different tissues
How do more dense tissues appear on X-ray?
More white
In what projection are CXRs usually taken?
PA, X-ray source behind patient
Why is AP projection sometimes used?
Patient too unwell to stand
What are the problems with AP projection?
X-ray beams are diverted by heart, due to heart being closer to source
Means heart looks bigger
What does a chest X-ray need to include?
Region above 1st rib
Lateral margins of rib (incase of lateral nodules)
Costophrenic angles
How would you check the rotation of a CXR?
Look if spinous processes are in between medial ends of clavicle
What does the patient need to do when a CXR is taken and why?
Needs to breath in and hold breath
Allows ribs 5-7 are in line with MCL
What will be seen if incomplete inspiration?
Big heart and increased lung markings
What will be seen in exaggerated expansion (obstructive)?
Flattened diaphragm
How can you check for adequate penetration?
Vertebrae just visible through heart
Left hemi-diaphragm visible
What are the right and left borders of the heart?
Right - RA
Left - LV
Where should the trachea be positioned?
Centrally
Which side are the hila higher on?
Left
What side is the aortic knuckle on?
Left
What side can bowel gas been seen on?
Left
How should the costophrenic and cardiophrenic angles present?
Sharp and pointy
How should you analyse an X-ray?
Adequacy A - airway B - breathing C - circulation D - diaphragm and bones
What is a silhouette sign?
Loss of crisp difference between adjacent structures with differing densities e.g. white heart next to black lung
What causes a mediastinal shift?
Changes to volume and pressure on one side of the chest
What is a pneumothorax?
Air trapped in pleural space causing uncoupling of lung from chest wall
What can cause a pneumothorax?
Spontaneous (trauma, fractured rib lacerates VP)
Underlying lung disease
Marfan’s
How is a large pneumothorax defined?
> 2cm from chest wall
How would a tension pneumothorax present on CXR?
Tracheal and mediastinal shift away from pneumothorax
Depressed diaphragm
How does a pleural effusion present on CXR?
Uniform white area due to liquid in pleural spaces
Obscures hemi-diaphragm and blunting of costophrenic angles
Meniscus at top
Mediastinal shift away
If patient is supine what will a pleural effusion look like?
Hazy all over
What is a lobar lung collapse and what can cause it?
Volume loss within lung lobe
Aspirated foreign material, mucus, carcinoma, compression by mass
What are some general findings on X-ray for lobar lung collapse?
Elevation of hemi-diaphragm on same side
Crowding of ribs
Mediastinal shift towards collapse
What specific findings are there for left lower lobe collapse?
Sail’s sigh - sharp line behind heart
What specific findings are there for left upper lobe collapse?
Veil sign - hazy opacification
What specific findings are there for right upper lobe collapse?
Horizontal fissure displaced up
What specific findings are there for right middle lobe collapse?
Right border of heart not seen
What specific findings are there for right lower lobe collapse?
Horizontal fissure displaced down
What is consolidation?
Give some examples
Filling of small airways and alveoli with dense material
e.g. pus (pneumonia), blood, fluid (oedema), cells (cancer)
How does a consolidation present on CXR?
Dense and white area
Air bronchogram
What is an air bronchogram?
Air-filled bronchi (dark) being made visible by the opacification of surrounding alveoli (grey/white)
What space occupying lesions can present on CXR?
Nodule < 3cm, Mass > 3cm
Malignant, inflammatory, bone lesion
How do asbestos plaques present on CXR?
Calcified, irregular, well defined, multiple
What is pneumoperitoneum?
Air under diaphragm due to bowel perforation
How is the cardiothoracic ratio calculated and what is a normal result?
Widest part of heart divided by widest part of ribcage
Normal < 50^%
