What colours are the following structures on ultrasound imaging?
- solids
- fluid
- gas
- bright
- dark
- bright
- Which type of organs is USS useful in imaging?
2. Name an advantage of USS
- solid
2. does not use ionising radiation
Which type of tissues appear white on plain film X ray images?
dense tissues (as they absorb more X rays)
Name a disadvantage of X rays
expose patients to low dose radiation
- Why is CT better than plain film? (2)
2. Why is CT worse than plain film?
- images can be reconstructed in any plane
able to distinguish more subtle density differences - much higher dose of radiation
- What contrast medium is used for most CTs?
2. What is the risk associated with the use of this
- Iodine
2. nephrotoxic
What does the term “phases” mean in relation to a CT scan?
relative time of contrast administration to when images are taken
- pre-contrast
- arterial
- venous
What is the colour of water in:
- T1 MRI?
- T2 MRI?
- What are each of these weighted images useful for clinically?
- water is dark
- water is bright
- T1 is better for viewing soft tissue structures
T2 is better for viewing pathology (inflammation; oedema)
- What is the contrast medium used for MRI?
2. What are the contraindications of the use of this contrast
- gadolinium
2. GFR <30
Name contraindications of MRI (3)
- metallic foreign bodies
- claustrophobia (patients may be unable to tolerate MRI scanner)
- severely obese patients (risk of burns)
- What type of imaging is nuclear medicine used for?
2. What is the basis of nuclear medicine?
- functional imaging - tells you what something is doing, but spacial resolution is poor
- uses small amounts of radiotracers that are injected, inhaled or swallowed. Taken up by functionally active structures; radiation is then detected by gamma cameras
Describe the systematic approach to presenting a chest plain film in 5 stages
- ” this is a chest radiograph”; comment on view, patient identifiers, date and time
- comment on adequacy - rotation; penetration; expansion
- comment on any obvious abnormality (usually refers to opacity in the lungs)
- where is it
- size
- shape
- borders
- density - comment on review areas
- what you think it is and what you would do
What are the review areas of a chest x ray? (7)
- 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 - mediastinum - size, contour
- lung fields
- ribs - any fractures; how many are visible (>8 indicates hyperinflation)
- diaphragm - pneumoperitoneum?; flattened indicates hyperinflation
- hila and apices
- breasts
Describe the following opacities seen on a chest x ray and what could cause them
- patchy
- dense
- rounded
- hard to draw around properly
- pulmonary oedema
- very white so you can’t see the structures through it
- pleural effusion
- consolidation
- discrete, rounded lesion
- mass lesion in the lung
- What causes mass positive abnormalities on a CXR?
2. Name 2 causes of mass positive abnormalities
- driven by processes whereby the alveoli secrete stuff, therefore the mass increases
fissures and trachea deviate away from the lesion - pneumothorax; pleural effusion
- What causes mass negative abnormalities on a CXR?
2. Name a cause of mass negative abnormalities on a CXR
- 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 - tumours that obstruct the airway
What are the common chest x ray findings of the following pathologies?
1. right upper lobe pneumonia/collapse
- right middle lobe pneumonia/collapse
- right lower lobe pneumonia/collapse
- left upper lobe pneumonia
- left upper lobe collapse
- left lower lobe pneumonia/collapse
- loss of mediastinal border
- loss of right heart border
- loss of diaphragmatic border
- loss of aortic arch sillhouette
- loss of lingula
- loss of diaphragmatic border
Describe the systematic approach to presenting an abdominal plain film in 7 stages
- This is an abdominal radiograph; add patient identifiers and date and time + view
- any obvious abnormality
- comment on bowel gas pattern
- comment on soft tissues
- any calcifications?
- comment on bones
- any lung bases?
- What does an angular pattern of gas meeting soft tissue indicate?
- What does a circular/rounded pattern of gas meeting with soft tissue indicate?
- free air
2. air within bowel
What is the 3-6-9 rule for dilated bowel loops?
3 - small bowel ≤3cm
6 - large bowel ≤6cm
9 - caecum ≤9cm
- What is a sigmoid volvus?
2. What is its characteristic finding on an abdominal plain film?
- 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
- coffee bean sign
- Is the spleen found anteriorly or posteriorly within the abdomen?
- What are the adrenal glands viewed as on a CT?
- Where is the aorta located in relation to the SVC?
- How is the ileocaecal valve viewed on a CT and why?
- posteriorly
- streaks medial to the kidneys
- right
- dark on a CT due to presence of fat
