Radiology

Question 1

What colours are the following structures on ultrasound imaging?

1. solids
2. fluid
3. gas

Answer 1

1. bright
2. dark
3. bright

Question 2

1. Which type of organs is USS useful in imaging?

2. Name an advantage of USS

Answer 2

1. solid

2. does not use ionising radiation

Question 3

Which type of tissues appear white on plain film X ray images?

Answer 3

dense tissues (as they absorb more X rays)

Question 4

Name a disadvantage of X rays

Answer 4

expose patients to low dose radiation

Question 5

1. Why is CT better than plain film? (2)

2. Why is CT worse than plain film?

Answer 5

1. images can be reconstructed in any plane
   able to distinguish more subtle density differences
2. much higher dose of radiation

Question 6

1. What contrast medium is used for most CTs?

2. What is the risk associated with the use of this

Answer 6

1. Iodine

2. nephrotoxic

Question 7

What does the term “phases” mean in relation to a CT scan?

Answer 7

relative time of contrast administration to when images are taken

• pre-contrast
• arterial
• venous

Question 8

What is the colour of water in:

1. T1 MRI?
2. T2 MRI?
3. What are each of these weighted images useful for clinically?

Answer 8

1. water is dark
2. water is bright
3. T1 is better for viewing soft tissue structures
   T2 is better for viewing pathology (inflammation; oedema)

Question 9

1. What is the contrast medium used for MRI?

2. What are the contraindications of the use of this contrast

Answer 9

1. gadolinium

2. GFR <30

Question 10

Name contraindications of MRI (3)

Answer 10

1. metallic foreign bodies
2. claustrophobia (patients may be unable to tolerate MRI scanner)
3. severely obese patients (risk of burns)

Question 11

1. What type of imaging is nuclear medicine used for?

2. What is the basis of nuclear medicine?

Answer 11

1. functional imaging - tells you what something is doing, but spacial resolution is poor
2. uses small amounts of radiotracers that are injected, inhaled or swallowed. Taken up by functionally active structures; radiation is then detected by gamma cameras

Question 12

Describe the systematic approach to presenting a chest plain film in 5 stages

Answer 12

1. ” this is a chest radiograph”; comment on view, patient identifiers, date and time
2. comment on adequacy - rotation; penetration; expansion
3. comment on any obvious abnormality (usually refers to opacity in the lungs)
   - where is it
   - size
   - shape
   - borders
   - density
4. comment on review areas
5. what you think it is and what you would do

Question 13

What are the review areas of a chest x ray? (7)

Answer 13

1. Heart - is it enlarged (can only be reviewed on PA film)
   - hiatus hernias can cause a pocket of air within the heart on a CXR
2. mediastinum - size, contour
3. lung fields
4. ribs - any fractures; how many are visible (>8 indicates hyperinflation)
5. diaphragm - pneumoperitoneum?; flattened indicates hyperinflation
6. hila and apices
7. breasts

Question 14

Describe the following opacities seen on a chest x ray and what could cause them

1. patchy
2. dense
3. rounded

Answer 14

1. hard to draw around properly
   
   • pulmonary oedema
2. very white so you can’t see the structures through it
   
   • pleural effusion
   • consolidation
3. discrete, rounded lesion
   
   • mass lesion in the lung

Question 15

1. What causes mass positive abnormalities on a CXR?

2. Name 2 causes of mass positive abnormalities

Answer 15

1. driven by processes whereby the alveoli secrete stuff, therefore the mass increases
   fissures and trachea deviate away from the lesion
2. pneumothorax; pleural effusion

Question 16

1. What causes mass negative abnormalities on a CXR?

2. Name a cause of mass negative abnormalities on a CXR

Answer 16

1. driven by processes which lead to decreased volume in the lung, therefore they collapse
   fluid tends to replace air; trachea and fissures move towards the lesion
2. tumours that obstruct the airway

Question 17

What are the common chest x ray findings of the following pathologies?
1. right upper lobe pneumonia/collapse

2. right middle lobe pneumonia/collapse
3. right lower lobe pneumonia/collapse
4. left upper lobe pneumonia
5. left upper lobe collapse
6. left lower lobe pneumonia/collapse

Answer 17

1. loss of mediastinal border
2. loss of right heart border
3. loss of diaphragmatic border
4. loss of aortic arch sillhouette
5. loss of lingula
6. loss of diaphragmatic border

Question 18

Describe the systematic approach to presenting an abdominal plain film in 7 stages

Answer 18

1. This is an abdominal radiograph; add patient identifiers and date and time + view
2. any obvious abnormality
3. comment on bowel gas pattern
4. comment on soft tissues
5. any calcifications?
6. comment on bones
7. any lung bases?

Question 19

1. What does an angular pattern of gas meeting soft tissue indicate?
2. What does a circular/rounded pattern of gas meeting with soft tissue indicate?

Answer 19

1. free air

2. air within bowel

Question 20

What is the 3-6-9 rule for dilated bowel loops?

Answer 20

3 - small bowel ≤3cm
6 - large bowel ≤6cm
9 - caecum ≤9cm

Question 21

1. What is a sigmoid volvus?

2. What is its characteristic finding on an abdominal plain film?

Answer 21

1. a loop of intestine twists around itself and the supporting mesentery resulting in a closed loop obstruction with open loop obstruction in the proximal large bowel
2. coffee bean sign

Question 22

1. Is the spleen found anteriorly or posteriorly within the abdomen?
2. What are the adrenal glands viewed as on a CT?
3. Where is the aorta located in relation to the SVC?
4. How is the ileocaecal valve viewed on a CT and why?

Answer 22

1. posteriorly
2. streaks medial to the kidneys
3. right
4. dark on a CT due to presence of fat