Respiratory radiology

Question 1

What is a silhouette?

Answer 1

air sitting next to something solid

Question 2

How do we know that the person has properly inspired prior to taking the CXR (PA)?

Answer 2

you can see 6-7 anterior ribs on the X-ray, and the heart is not enlarged; and 10 posterior ribs

Question 3

What do you normally see in lung fields as opaque structures?

Answer 3

pulmonary arteries and pulmonary veins + soft tissues

Question 4

What is the cardiothoracic ratio normally on PA film?

Answer 4

<50%

Question 5

What can cause decreased and increased lung volumes?

Answer 5

Pulmonary fibrosis and COPD respectively. A hyperinflated lung in COPD–> lung volumes expand sagittally as well as anteriorly. The diaphragm flattens and appears serrated. Greater than 2cm from costophrenic angle to cardiophrenic angle

Question 6

where would you look for right middle lobe?

Answer 6

Under the right axilla.

Question 7

what can cause increased opacity in the lung fields?

Answer 7

pleural fluid, atelectasis, oedema/consolidation in airspaces, tumours, abscesses

Question 8

Pleural effusion description

Answer 8

Usually basal–> blunting of costophrenic angle. Has a curving up meniscus, and appears less opaque more superiorly. Can be caused by infection or cardiac failure.

Question 9

What can cause alveolar opacity?

Answer 9

pulmonary oedema and consolidation

Question 10

what can cause interstitial opacity?

Answer 10

pulmonary oedema, pulmonary fibrosis

Question 11

What is another cause of lung opacity?

Answer 11

tumour or metastases

Question 12

What can cause increased lucency (blackness) in lung fields?

Answer 12

pneumothorax, bullous emphysema

Question 13

Why might we need an expiratory chest Xray?

Answer 13

if we suspect a pneumothorax, the features of pneumothorax will be more exaggerated.

Question 14

What do we do if we suspect a PE?

Answer 14

CT pulmonary angiogram

Question 15

If we see tubular opacities on CXR…

Answer 15

think bronchiectasis

Question 16

CT- what is the units of plain water and blood?

Answer 16

plain water= zero units, blood= 40-50 units

Question 17

what do we see in COPD on a plain CXR?

Answer 17

lung hyperinflation, flattened diaphragm, small heart on PA X-ray. On lateral CXR, increased AP diameter

Question 18

would you see the right ventricle on a frontal projection?

Answer 18

no. but you can see it on a lateral CXR, bc it’s retrosternal

Question 19

which hemidiaphragm is elevated?

Answer 19

right bc of liver

Question 20

Consolidation that obscures the right upper mediastinal silhouette?

Answer 20

means that consolidation in the right upper lobe

Question 21

Consolidation that obscures the right hemidiaphragm silhouette?

Answer 21

means that consolidation in the right lower lobe

Question 22

Consolidation that obscures the right side of the cardiac border?

Answer 22

means that consolidation in the right middle lobe

Question 23

If you have consolidation in the left lingula lobe- which silhouette do you obscure?

Answer 23

left cardiac border

Question 24

2 main causes of bilateral airspace opacities post operatively?

Answer 24

Aspiration pneumonia or fluid overload due to fluid or blood transfusions.

Question 25

What do you think the lateral CXR show for Mitral valve disease show?

Answer 25

The oesophagus is indented as the left atrium grows posteriorly.

Question 26

What are 3 causes of massive cardiomegaly

Answer 26

1. cardiomyopathy, 2. pericardial effusion

3. mixed valvular disease

Question 27

what would you see for radiation pneumonitis?

Answer 27

a pleural effusion in the area where radiation is targeted.

Question 28

what would you see for pulmonary fibrosis?

Answer 28

Decreased lung volumes + diffusely increased interstitial opacity= pulmonary fibrosis

Question 29

what would you see in an X-ray for COPD?

Answer 29

Hyper inflated lungs, flattened diaphragm. Lateral chest X-ray shows barrel chest–> increased AP diameter. Increased lucency. Small cardiac size.

Question 30

what would you think if you see a cavitating lesion on CXR?

Answer 30

you would think:

1. TB
2. Cancer
3. Pulmonary abscess

Question 31

what would you think if you saw widespread consolidation on a CXR?

Answer 31

ARDS- acute respiratory distress syndrome= diffuse alveolar damage

Question 32

how can you tell which hemidiaphragm is which for lateral CXR

Answer 32

heart is attached to left hemidiaphragm so look for that

Question 33

what is the aortopulmonary window? what is its clinical significance?

Answer 33

between aorta and pulmonary artery on CXR frontal. If something in it the space- abnormal, possibly enlarged lymph node

Question 34

which hilum is higher?

Answer 34

left hilum