M103 T4 L18 Flashcards
What are the review areas for when assessing a CXR?
(ABCHP) Apices Behind the heart Costo-phrenic angle Hila Peripheries
Why are the lung apices described as having bone crowding?
the first and second ribs are quite close together.
the clavicle comes across the towards the midline again, obscuring the lung apices
So how do you assess heart size on a CXR?
using the cardiothoracic ratio
What does the cardiothoracic ratio state?
that the cardiac width should measure less then half the thoracic width
How are PA CXR taken?
the patient faces the X-ray plate
the X-ray beam comes from behind the patient
so the heart is as close to the X-ray plate as you can get it - this stops the magnification effect
AAR the cardiothoracic ratio can be used accurately
What are the main advantages of CT scans?
Great spatial resolution- especially bone
Cheap & available
Easy interpretation
What are the main disadvantages of CT scans?
Projectional (2D)
Ionising radiation
Very limited soft tissue visualisation
What is the slice thickness for CT thorax scans?
1 - 5mm
How could we produce a steady state image of lung blood flow?
by injecting a radioisotope into the bloodstream to see where it runs within pulmonary arteries
putting the patient in a position where they’re lying on their back
What is an example of a common chest pathology?
pneumothorax
What is the most dangerous kind of pneumothorax?
tension pneumothorax
What are examples of trauma that could cause a tension pneumothorax?
an open wound within the chest, either from a rib fracture that’s penetrated both the pleura and the skin
a stab wound
What can cause consolidation in the lungs?
infections - pus
pulmonary haemorrhage
How many alveoli per adult?
300 million
What is the total area of all the alveoli in an adult?
143 m2
