Radiology

Question 1

Which colour will the following show up as on a CXR:

• Air
• Fat
• Soft tissue/muscle
• Fluid
• Bone
• Metal

Answer 1

• Air = Black
• Fat = Grey
• Soft tissue/muscle = Grey/white
• Fluid = grey
• Bone = white
• Metal = Bright white

Question 2

Is extra thoracic or intra thoracic air more dense?

Answer 2

Intrathoracic

Question 3

Passage of sound waves through fluid, soft tissue, air and bone, and the shades seen on the ultrasound

Answer 3

Fluid - allows passage of sound waves, black colour
Soft tissue - allows passage of sound waves, bright
Air - blocks passage of sound waves, shadow
Bone - blocks passage of sound waves, shadow

Question 4

Technique for standard PA view X-ray

Answer 4

• Patient stands 2m from x-ray apparatus, facing digital cassette
• Shoulders braced forward so scapulae do not obscure lungs
• Radiograph taken at full inspiration
• X-rays pass from posterior to anterior

Question 5

Why are AP X-rays inferior to PA X-rays?

Answer 5

Heart shadow is magnified so heart size cannot be assessed accurately
Scapulae overlie and partly obscure the lungs
Can be difficult for patient to take adequate inspiration

Question 6

What things must you check before you begin to analyse a chest X-ray?

Answer 6

• Patient’s name and date of birth to ensure you are looking at the correct person’s X-ray
• Is there a side marker? Are you looking at it the right way round?
• Is it technically adequate? - inspiration, rotation and penetration

Question 7

How to tell if a chest X-ray is adequately inspired

Answer 7

The anterior ends of at least 6 ribs should be visible

Question 8

How to tell if a chest X-ray is correctly centred

Answer 8

The medial ends of the clavicles should be equidistant from the spinous process of the upper thoracic vertebrae

Question 9

Situs inversus

Answer 9

Congenital anomaly where the large organs are swapped from left to right

Question 10

Which lung lobes do an anterior chest X-ray show?

Answer 10

Right upper lobe, right middle lobe, left upper lobe, lingula

Question 11

Which lung lobes do a posterior chest X-ray show?

Answer 11

Right lower lobe, left lower lobe

Question 12

Which anatomical findings are shown on a lateral chest X-ray?

Answer 12

Oblique fissure, horizontal fissure, posterior costophrenic recess, retrosternal space

Question 13

Where imaging is indicated in suspected pulmonary embolism

Answer 13

CXR normal = VQ scan
Radiation to be avoided or clinical suspicion of DVT consider US of leg
CXR abnormal or massive PE suspected CT pulmonary angiogram

Question 14

Peripheral tumours and central tumours

Answer 14

Peripheral tumours - tumours arising beyond the hilum

Central tumours - tumours arising at or close to the hilum

Question 15

Peripheral tumours on CXR

Answer 15

Rarely visible if <1cm diameter. Usually spherical or oval

Question 16

Cardinal signs of central tumours

Answer 16

Hilar enlargement, distal collapse/consolidation

Question 17

Benefits of contrast enhanced CT in staging of tumours

Answer 17

• Assess tumour size
• Show intracranial metastases
• Guide biopsy of peripheral lesions

Question 18

In relation to tumours, what is a PET CT good at detecting?

Answer 18

Nodal metastases, distant metastases, delineating tumour in area of collapse

Question 19

Which abnormality is often marked in imaging of a patient with small cell lung cancer?

Answer 19

Mediastinal adenopathy

Question 20

What can an ultrasound be used to detect?

Answer 20

Pleural effusion, subphrenic collection, movement of diaphragm, US guided drainage