IOD Chest Imaging

Question 1

What does consolidation mean?

Answer 1

material filling in the alveoli

makes affected area appear white on CXR-more dense

Question 2

air bronchograms?

Answer 2

large airways not filled with material but air which creates these if smaller airways are filled

Question 3

Causes of consolidation?

Answer 3

Pus
Pneumonia
Water
Pulmonary oedema
Blood
Trauma
Vasculitis
Cells
Eg Tumour

Question 4

Silhouette Sign?

Answer 4

If there is consolidation in lung that is against another structure eg heart, the normal interface between air and soft tissue is lost so the border of that structure is no longer visible

Question 5

left diaphragmatic border SS?

Answer 5

Left lower lobe consolidation

Question 6

apex SS?

Answer 6

lingula consolidation

Question 7

right border SS?

Answer 7

Right middle lobe consolidation

Question 8

Right diaphragmatic border SS?

Answer 8

right lower lobe consolidation

Question 9

infections?

Answer 9

Lobar pneumonia- commonly bacterial cause eg strep pneumoniae

Question 10

Pulmonary TB?

Answer 10

Upper lobe consolidation
Cavity formation
Hilar lymphadenopathy

Question 11

lung cancer?

Answer 11

Usually presents as a nodule (<3cm) or mass (>3cm) on chest x-ray
May be primary lung cancer- more common in smokers
May be secondary- metastases from elsewhere, more likely if multiple

Question 12

Review areas?

Answer 12

clavicles/apex
hilar
behind heart
below diaphragm

Question 13

Lung cancer signs?

Answer 13

Look out for lymphadenopathy-hilar/mediastinal
Pleural effusion
Bony mets

Question 14

cardiac failure?

Answer 14

Insufficient cardiac output due to:
Failure of heart to pump adequately
High circulatory resistance
Fluid overload
Left ventricular failure is the most common
Results in ↓cardiac output and ↑pulmonary venous pressure
Right ventricular failure usually occurs due to longstanding LV failure or pulmonary disease
Causes ↑ systemic venous pressure → peripheral oedema

Question 15

Heart failure signs?

Answer 15

Heart size
Pulmonary vessel & parenchymal changes
Pleural changes

Question 16

heart size?

Answer 16

Cardiomegaly
Cardiothoracic ratio > 0.5-heart width over thoracic width
Must assess on a PA radiograph

Doesn’t always mean failure. DDx:
Pericardial effusion, cardiomyopathy, etc

Question 17

Radiological features of HF?

Answer 17

Radiological features progress as pressures increase
Normal pulmonary capillary pressure 5-12 mmHg
12-17mmHg: Pulmonary vascular redistribution
17-20mmHg: Interstitial oedema
>25mmHg: Alveolar oedema & pleural effusion

Question 18

Upper lobes diversion?

Answer 18

: erect film only – upper lobe vessels are smaller and fewer due to gravity. But pulm vascular bed has great reserve capacity. When pressure goes up, more vessels are recruited, opening up new and distending established vessels (more in the upper lobes) to pulmonary blood flow therefore blood RE-DISTRIBUTES to the upper lobes.

Question 19

Kerly B?

Answer 19

They are perpendicular to the pleural surface and extend out to it. They represent thickened subpleural interlobular septa and are usually seen at the lung bases

Question 20

interstitial oedema?

Answer 20

Upper lobe venous diversion PCP ~ 15mmHg

Kerley B lines ~ 15-20 mmHg

Question 21

alveolar oedema?

Answer 21

Aveolar odema-Bat-wing &

pleural effusions > 25 mmHg

Question 22

pneumothorax?

Answer 22

Important diagnosis- potential medical emergency
Air in pleural cavity, compresses underlying lung
Defect in parietal or visceral pleura
Aetiology:
Primary spontaneous
Secondary- emphysema, asthma, infection
Trauma- penetrating injury

Question 23

Signs in Pneumothorax?

Answer 23

Erect chest radiograph:
Sharp white line of visceral pleura
No lung markings between this and chest wall
May see blunting of costophrenic angle – with small amount of pleural fluid
Do not confuse with skin fold – these extend beyond margin of lung fields and have lung markings beyond them

Question 24

tension pneumothorax?

Answer 24

One way valve effect- air can enter pleural space but not leave
Rapid collapse of underlying lung and mediastinal shift
Imminent cardiovascular collapse- URGENT management

Question 25

COPD ?

Answer 25

Hyperinflation
Flattened diaphragm
Eight anterior ribs visible 
Heart appears vertically oriented (‘stretched out’)
Coarse bronchovascular markings- ‘dirty lungs’
Look for complications:
Infection- consolidation
Pneumothorax
Lung cancer

Question 26

measuring hemidiaphragm?

Answer 26

Hemi-medial to lateral and if less than 1.5 cm of diaphragm above

Question 27

pulmonary embolism?

Answer 27

Thrombus in the pulmonary arteries
Has usually travelled (embolised) from deep venous thrombosis in legs or elsewhere
If large, can cause significant haemodynamic compromise
CT pulmonary angiogram performed for diagnosis- dedicated CT with IV contrast timed to assess the pulmonary arteries

Question 28

CTPA considerations?

Answer 28

sig renal impairment
ionising radiation
preg and breastfeeding
V/Q scan instead
nuclear medicine test?