Session 8 - Radiology of the chest

Question 1

Which is ideal, a PA or AP chest xray? When is each done?

Answer 1

• PA (posterior to anterior) – Xray done when person is facing a wall and is ideal. This is because the heart is closer to the chest and if the Xray hits the heart first it would magnify it, in much the same way that a shadow puppet is magnified when closer to the source of light.
• AP (anterior to posterior) – Done when the patient is sitting down, usually because they are unable to stand. Inferior to PA. Can see the scapula in AP.

Question 2

How do you use the trachea to align yourself in an chest X ray?

Answer 2

• Spinous process of the trachea should be in the middle of the ends of the clavicles. Otherwise there is tracheal deviation.

Question 3

Why should the patient take a complete inspiration before taking the CXR? Where is the diaphragm located in a full inspiration CXR?

Answer 3

• Patient must take a full inspiration in so that the diaphragm can be located between the 5th and 6th intercostal space.
• If incomplete inspiration:

o Structures compressed upwards making heart look bigger and ribs closer

Question 4

What is an artifact?

Answer 4

external or surgical material which obstructs the view

Question 5

Label

Answer 5

Question 6

What part of the heart is depicted in the left and right heart borders?

Answer 6

Left heart border is the left ventricle.

Right heart border is the right atrium.

Question 7

Which hilar point is higher? What could the hilar points be used to indicate?

Answer 7

Left hilar points should always be above the right.

Collapse in the lung moves the hilar points

Question 8

What is the carina and what can make it smaller?

Answer 8

Splitting of the bronchi. Angle is very important and can be made larger by a growth underneath e.g. growth of atria

Question 9

What might loss of a silhouette of an organ indicate?

Answer 9

pathology

Question 10

Give the ABC approach for assessing CXR.

Answer 10

• Adequacy
• Airway
• Breathing
• Circulation
• Diaphragm / Dem bones

Question 11

How would you assess adequacy?

Answer 11

RIP

R – Rotation – Spinous processes at midpoint between medial ends of the clavicles?

I – Inspiration – Diaphragm found at 5th to 6th intercostal space?

P – Penetration – Spine visible behind the heart?

Question 12

How would you assess airways in a CXR?

Answer 12

• Hila – check left hilum is above right
• Trachea – check trachea is central

Question 13

How would you assess breathing in a CXR?

Answer 13

• Check the lungs, pleural spaces, lung interfaces.
• Are there any nodules? Consolidation? Calcification? Compare the 2 sides.

Question 14

How would you assess circulation in a CXR?

Answer 14

Check the mediastinum:

o Aortic arch

o Pulmonary vessels with hila

o Right heart border – right atrium

o Left heart border – left ventricle and lingula interface (tongue of left lung)

Question 15

How would you assess diaphragm / bones?

Answer 15

Check for free gas, nodules, fractures, and masses

Question 16

What is a pneumothorax? What would be shown on an xray of a tension pneumothorax?

Answer 16

Air trapped in a pleural space Lung is black due to trapped air in chest

Trachea may deviate due to higher pressure

Depression of diaphragm due to pressure

Loss of lung markings

Question 17

What is a pleural effusion? What would be shown on a CXR of a pleural effusion?

Answer 17

Collection of fluid in the pleural space

Uniform white area

Loss of costophrenic angle - angle at which diaphragm and chest wall meet

Obscured diaphragm

Visible meniscus

Mediastinal shift due to pressure

Question 18

What are the 3 likely causes of lobar lung collapse?

Answer 18

Child - aspirated foreign material

>40 - cancer

Asthmatics - mucous plugging

Question 19

What would be shown on a CXR of a lobar lung collapse?

Answer 19

Mediastinal shift towards collapse due to lower pressure

Elevation of diaphragm.

Question 20

Define consolidation

Answer 20

Filling of the small airways / alveoli with stuff

Question 21

What would be shown on a CXR of consolidation?

Answer 21

Dense opacification over the area with preservation of volume

Question 22

What would cause a space occupying lesion? Give 3 things

Answer 22

Inflammation, malignancy, congenital

Question 23

How would you identify cardiac enlargement on a CXR?

Answer 23

Cardiac index - Ratio of heart to thoracic cavity should be less than 50% on a PA image

Question 24

Give the pathology of fibrosing alveolitis. What would be shown on a CXR? What would a lung function test reveal?

Answer 24

Increased activated alveolar macrophages which attracts neutrophils and eosinophils, resulting In lung damage due to ROS and proteases. Tissue destruction and fibrosis occurs. idiopathic

X-ray – Small lungs with micro-nodular shadowing predominating in the lower lobes with ragged heart borders

Lung function test shows reduced compliance and reduced gas transfer

Question 25

What would a CXR of sarcoidosis reveal?

Answer 25

Miliary and nodular shadowing and diffuse fibrosis

Question 26

Give 4 factors that would increase pleural fluid in the pleural space.

Answer 26

• Lymphatic obstruction
• Increased capillary permeability,
• Decreased oncotic pressure,
• Increased capillary venous pressure,

Question 27

Give the terms for extra: a) blood b) chyle c) pus d) serous fluid in the pleural space.

Answer 27

a) haemothorax b) chylothorax c) empyema d) simple effusion

Question 28

Define a transudate and an exudate

Answer 28

Transudate – Low protein content <30g/litre

Exudate - High protein content >30g/litre

Question 29

Give 3 factors that would result in transudate pleural effusion

Answer 29

• Increased hydrostatic pressure e.g. cardiac failure
• Decreased oncotic pressure e.g. hypoalbuminaemia, nephrotic syndrome
• Increased capillary permeability e.g. sepsis

Question 30

Give 3 factors that would result in exudate pleural effusion.

Answer 30

• Neoplasms – cancers producing pleural fluid
• Infection e.g. pneumonia and TB
• Immune disease e.g. connective tissue diseases

Question 31

What 3 things can cause pleuritis?

Answer 31

• Infection e.g. TB and pneumonia
• Autoimmune
• Lung cancer – Tumours of the pleura can result in large pleural effusion
• Pneumothorax

Question 32

What are the 4 symptoms of pleuritis?

Answer 32

• Sharp pain on inspiration
• Pain worse on coughing, sneezing, laughing etc.
• Involvement of diaphragmatic pleura results in Referred pain in shoulder
• Pleural rub – creaking noise heard on auscultation with respiratory movements

Question 33

What 3 chest wall abnormalities might affect breathing?

Answer 33

• Deformation of ribs, sternum and thoracic spine •

Scoliosis and kyphosis may produce impairment of thoracic cage

• Trauma producing broken ribs, possible pneumothorax

Question 34

How might muscle or neurological disease affect breathing?

Answer 34

• If muscles involved in breathing affected by generalised muscular diseases e.g. muscular dystrophy or MND
• Muscle weakeness produces resp failure with lower resistance to RTI due to poor clearance of secretions