Radiology 1 and 2

Question 1

What is the Xray dose for a CXR?

Answer 1

0.02mSv

Question 2

What is the Xray dose for a Chest CT?

Answer 2

10mSv

Question 3

On average how much background radiation does the average person absorb?

Answer 3

2.2mSv/yr

Question 4

From darkest to lightest describe the different densities in an Xray?

Answer 4

Darkest 
Air 
Fat 
Soft tissue 
Bone 
Metal 
Lightest

Question 5

Is it better to take a breath out and hold or breath in and hold when having an xray?

Answer 5

Taking a breath in so you can see more of the lungs and chest

Question 6

What is the lingula and where is it?

Answer 6

The left lung, unlike the right, does not have middle lobe, though it does have a homologous feature, a projection of the upper lobe termed the “lingula”. Its name means “little tongue”. The lingula on the left serves as an anatomic parallel to the right middle lobe, with both areas being predisposed to similar infections and anatomic complications.There are two bronchopulmonary segments of the lingula: superior and inferior.

Question 7

What is the difference when looking at the lung posteriorly, lobe wise?

Answer 7

The lower lobes overlap the other lobes so it may be hard to distinguish if an abnormality lies within the middle of lower lobe.

Question 8

If you can still still the boarders of the right side of the heart what does that mean in terms of the middle lobe being affected?

Answer 8

The middle lobe is usually fine if you can still see the boarders of the heart.

Question 9

In a suspected PE what should you do if the CXR is normal?

Answer 9

A V/Q scan

Question 10

In a suspected PE what should you do if radiation needs to be avoided/the leg is swollen?

Answer 10

Ultrasound for leg for DVT

Question 11

In a suspected PE what should you do if the CXR has an abnormal/massive PE suspected?

Answer 11

CT Pulmonary Angiogram

Question 12

What are the clinical features and pathology of lung cancer?

Answer 12

Asymptomatic (15% to 25% at diagnosis) especially peripheral tumours.

Symptoms: cough, wheeze, haemoptysis, recurrent pneumonia, hypercalcemia, Weight loss, hoarseness, finger clubbing, persistent supra-clavicle nodes

Question 13

What are some predisposing conditions to lung canceR?

Answer 13

Inhalation of carcinogens e.g. cigarette smoke, asbestos
Bronchioalveolar adenoma
Lipoid pneumonia
Interstitial pulmonary fibrosis
Previous lung cancer. Remember tumours can be synchronous and metachronous
NOT in Scars due to old TB

Question 14

What are peripheral tumours?

Answer 14

Tumours arising beyond the hilum

Question 15

What are central tumours?

Answer 15

Tumours arising at or close to the hilum

Question 16

What are some cardinal signs of a central tumour?

Answer 16

Hilar enlargement

Distal collapse/consolidation

Question 17

When is contract enhance CT good for in terms of staging cancer?

Answer 17

Assessing tumour size
showing intracranial metastases
Guiding a biopsy of peripheral lesions

Question 18

When is a PET CT good in terms of staging cancer?

Answer 18

Nodal metastases
Distant metastases (not brain metastases)
Delineating tumour in an area of collapse

Question 19

When is an MR good for staging cancer?

Answer 19

Does not require IV contrast to see vessels
3 planes valuable at apex, aortopulmonary window and supradiaphramtic regions
Better soft tissue differentiation

HOWEVER

Costly
Time-consuming
Spatial resolution better with CT
Need gating to reduce motion artefacts

Question 20

Why in general is a PET scan good to find cancer?

Answer 20

Cancer requires glucose to survive, shows up very well on PET scan

Question 21

Name some radiological interventions?

Answer 21

CT guided lung biopsy
Pleural fluid drain
SVC stenting

Question 22

In what position are X-rays usually taken?

Answer 22

PA

Question 23

What are the disadvantages in an AP X-ray in someone who is unable to get an PA CXR?

Answer 23

The heart shadow is magnified so heart size cannot be assessed accurately
The scapulae overlie and partly obscure the lungs
It can be difficult for the patient to take an adequate inspiration

Question 24

How many ribs should be visible if the CXR is adequately inspired?

Answer 24

At least 6 ribs - anterior ends

At least 10 ribs - posterior (easier to see)

Question 25

If the CXR is correctly centred the medial ends of the clavicles should be what?

Answer 25

equidistant from the spinous processes of the upper thoracic vertebrae

Question 26

How many lobes does the right lung have?

Answer 26

3

Question 27

How many lobes does the left lung have?

Answer 27

2

Question 28

If you can still see the diaphragm what does that mean in terms of disease?

Answer 28

The lower lobe is usually not involved

Question 29

What does an infection of the lingula cause?

Answer 29

causes the left heart border to become obscured

Question 30

What happens when a lobe collapses?

Answer 30

The lobe supplied by an obstructed bronchus is no longer ventilated and its air gets resorbed. As the affected lobe loses volume it begins to collapse, like a balloon deflating.
The collapsed lobe’s density increases and the adjacent major fissure is dragged out of position – these features are visible on a CXR and each lobe has a predictable CXR appearance when collapsed.

Question 31

Where should an ET tube be places?

Answer 31

2cm above carina