Chest X Rays

Question 1

What are the 2 types of CXRs and which is better quality

Answer 1

PA projection - from standing, better quality

AP projection - from sitting, heart is magnified as farther from receptor so more divergence of X-rays

Question 2

What is included in a CXR

Answer 2

1st rib to Costophrenic angles

Lateral margins of ribs

Question 3

What does adequacy depend on

Answer 3

Rotation - spinous process visible between medial parts of clavicles
Inspiration - 5-7th anterior ribs at mid Clavicular lines
Penetration - spinous process visible through heart shadow and entire left hemidiaphragm is visible

Question 4

Describe ABCDE approach

Answer 4

Airways - trachea, bronchi and hila
Breathing - lungs, pleural spaces, lung interfaces
Circulation - aortic knuckle, heart borders, pulmonary vessels
Diaphragm and bones - free gas, fractures, elevated/depressed diaphragm
Everything else

Question 5

What is a silhouette sign

Answer 5

Silhouette formed between adjacent structures of differing density
Where silhouette sign is lost, there is a pathology

Question 6

Give examples of where silhouette sign is lost and where the pathology responsible is

Answer 6

Right heart border - right middle lobe
Left heart border - left upper lobe (lingula)
Paratracheal stripe - mediastinum
Chest wall - lung, pleura, ribs
Diaphragm - lower lung lobes
Aortic knuckle - anterior mediastinum or left upper lobe
Horizontal fissure - right upper lobe

Question 7

Describe mediastinal shift

Answer 7

Deviation of trachea/heart
Push: increased pressure or volume e.g tension pneumothorax, pleural effusion
Pull: decreased pressure or volume e.g fibrosis, iatrogenic, lung collapse

Question 8

What is a pneumothorax

Answer 8

Air in the pleural space

Question 9

Types of pneumothorax

Answer 9

Primary spontaneous - usually trauma (look for complications of fracture)
Secondary spontaneous - emphysema, asthma, Marfan’s
Iatrogenic
Tension pneumothorax

Question 10

What is a tension pneumothorax

Answer 10

Depressed hemidiaphragm on the affected side AND a mediastinal shift away from the pneumothorax

Question 11

What is a large pneumothorax

Answer 11

> 2cm from inner chest wall at level of the hilum

Question 12

Symptoms of a pneumothorax

Answer 12

Pleuritic chest pain

Dyspnoea

Question 13

How do you investigate a pneumothorax

Answer 13

Past medical history - underlying condition, previous surgery
CXR unless tension pneumothorax (not enough time)

Question 14

Treatment of pneumothorax

Answer 14

Discharge if no SOB
Aspiration for primary and small secondary pneumothorax
Intercostal chest drain if aspiration fails, large secondary and tension pneumothorax

Question 15

What is pleural effusion

Answer 15

Collection of fluid in the pleural space

Question 16

Types of pleural effusion

Answer 16

Haemothorax (blood)
Chylothorax (chyle)
Empyema (pus)
Simple effusion (serous fluid)

Question 17

Appearance of CXR in pleural effusion

Answer 17

Uniform white area
Meniscus
Loss of Costophrenic angles
Obscured hemidiaphragm

Question 18

Types of simple effusions and how are each caused

Answer 18

Transudate - high venous pressure or low oncotic pressure (pleural protein:serum protein >0.5)
Exudate - infection, RA, malignancy of pleura, ascites

Question 19

What is atelectasis

Answer 19

Volume loss within lung lobe

Question 20

Causes of atelectasis

Answer 20

Luminal - mucous plugging, aspirated foreign material, iatrogenic)
Mural - bronchogenic carcinoma
Extrinsic - compression

Question 21

CXR features of atelectasis

Answer 21

Hemidiaphragm elevation on affected side, mediastinal shift towards collapse, crowding of ribs and pulmonary vessels

Question 22

What is consolidation

Answer 22

Airways filled with pus, fluid (oedema, blood) , cells

Question 23

What cause space occupying lesions

Answer 23

Malignancy 
Benign masses 
Inflammation e.g TB granulomas 
Congenital 
Artefact

Question 24

What is the normal cardiac index and how is it measured

Answer 24

On a PA projection

Cardiac:thoracic <0.5

Question 25

What is a sail sign

Answer 25

Atelectasis affecting right lower lobe

Question 26

What is a veil sign

Answer 26

Atelectasis affecting right upper lobe