Respiratory imaging

Question 1

Put the relative CT densities of the following materials in order of increasing density (i.e. brighter white):

WATER

AIR

MUSCLE

FAT

BONE

METAL

LUNGS

CONTRAST

Answer 1

• AIR -1000
• LUNGS - 500
• FAT - 100
• WATER 0
• MUSCLE + 50
• BONE + 200
• CONTRAST + 500
• METAL + 1000

Question 2

What is the appearance of each of the following on Ultrasound ?

Answer 2

• Fluid allows passage of sound waves = black
• Soft tissue allows passage of sound waves = bright
• Air blocks passage of sound waves = shadow
• Bone blocks passage of sound waves = shadow

Question 3

Flick through intro resp imaging lecture week 1

Question 4

Answer 4

Question 5

Answer 5

Question 6

List the risk factors for lung cancer development

Answer 6

• 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 7

What are the clinical features suggestive of a lung cancer?

Answer 7

• Asymptomatic (15% to 25% at diagnosis) especially peripheral tumours.
• Symptoms: cough, wheeze, haemoptysis, recurrent pneumonia, hypercalcemia
• Signs; Weight loss, hoarseness, finger clubbing, persistent supra-clavicle nodes

Question 8

In terms of imaging what are the 2 types of lung cancers?

Answer 8

1. Peripheral Tumours = tumours arising beyond the hilum
2. Central Tumours = tumours arising at or close to the hilum

Question 9

What are the signs on imaging suggestive of a peripheral lung tumour ?

Answer 9

• 40% bronchial ca rise beyond segmental bronchi
• Rarely visible on chest X-ray if < 1cm diameter
• Usually spherical or oval
• Volume doubling time vary between 40 and 400 days (for solid tumours)

Question 10

What are the signs on imaging of a central lung tumour ?

Answer 10

• Hilar enlargement
• Distal Collapse/consolidation