How to look at a CXR

Question 1

What can ionising radiation cause

Answer 1

cancer

Genetic defects

Question 2

What imaging uses ionising radiation

Answer 2

• Plain XR
• CT
• Nuclear medicine
• PET

Question 3

Describe the anatomy of the lung

Answer 3

Left

• superior lobe
• inferior lobe
• has an oblique fissure

Right

• superior lobe
• middle lobe
• inferior lobe
• horizontal fissure separating superior and middle lobe
• oblique fissure separating middle and inferior lobe

Question 4

Where does the oblique fissure start

Answer 4

T4

Question 5

the darkness of the film reflects…

Answer 5

Darkness of film reflects exposure to Xrays

Question 6

What are the 4 densities in X rays

Answer 6

1. Air – no absorption – black
2. Fat – little absorption – dark
3. Water / soft tissue – more absorbed - mid grey
4. Bone / calcium - white

Question 7

what is the normal view of the chest X ray

Answer 7

PA

Question 8

How should you look at a chest X ray

Answer 8

• Name, DOB,
• check the side marker is on the right side
• check the position of the patient - look for the end of the clavicles and compare that to the spinous process posteriorly
• check the exposure - make sure you can see everything - look for the vetebral bodies and IV spaces through the mediastinum
• should be able to see lung markings 2/3 of the way out to the chest wall
• you should assess the heart size - CTR should be less than 0.5
• look at the aortic knuckle
• main pulmonary arteries
• then the left atrial appendage
• then the left ventricle
• then the SVC
• ascending aorta
• right atrium
• IVC
• then look at the hilar
• diaphragm
• then compare the densities of the lung
• then if you still havent found anything come back to the review area - behind head of clavicles, behind the heart shadow, and behind the diaphrgam

Question 9

What should the cardaic throacic ratio be

Answer 9

• less than 0.5

Question 10

What happens in an AP film with the heart

Answer 10

• Heart can become enlarged - no longer check the CTR ratio

Question 11

CTR only applies to a

Answer 11

PA patient with an erect view

Question 12

What does the chest x ray look like in pneumonia

Answer 12

• Increased density (whiteness)
• Silhouette sign = loss of normal
  outlines
• Air bronchograms