EXAM #1: ABNORMAL CXR

Question 1

What is the “Silhouette Sign?”

Answer 1

Loss of a border b/c two substances of same radiographic density are in direct contact

Question 2

What is the “Air Bronchogram Sign?”

Answer 2

Consolidation allowing for visualization of bronchi

*Note that this indicates that the bronchi is OPEN

Question 3

What are the five mechanisms that cause lung volume loss?

Answer 3

1) Bronchial obstruction
2) Air/fluid in the pleural space
3) Scarring
4) Decreased surfactant
5) Hypoventilation from CNS depression or pain

Question 4

What are the direct signs of lung collapse?

Answer 4

1) Displacement of the fissures

2) Increased density of affected portion

Question 5

What are the indirect signs of lung collapse?

Answer 5

1) Hilar displacement (left should be higher)
2) Deviation of trachea to affected side
3) Cardiac displacement toward side of collapse
4) Narrownig of rib cage of affected side
5) Compensatory overaeration of the adjacent normal lung

Question 6

What is the most common cause of a collapsed lung in: kids, adult under 40, adults over 40?

Answer 6

Kids= mucous plug/aspirated FB

Under 40= low grade endobronchial tumor

Over 40= bronchogenic carcinoma

Question 7

What is the name given to the structures that support the lung i.e. arteries, veins, bronchi, and lymphatics?

Answer 7

Interstitium

*Can be thickened or thinned, mostly chronic

Question 8

What are the air sacs in the lung referred to as?

Answer 8

Alveoli

*Note that this is mostly acute

Question 9

What are the five things that can fill the alveoli?

Answer 9

• Water
• Pus
• Blood
• Proteinaceous fluid
• Tumor

Question 10

What are the three patterns of interstitial thickening?

Answer 10

1) Generalized= linear/reticular
2) Discrete= multiple small nodules
3) Combination= reticulonodular

Question 11

What is the most common cause of chronic diffuse interstitial lung disease?

Answer 11

Fibrosis

Question 12

What is the most reliable method for distinguishing between acute and chronic changes on CXR?

Answer 12

Old films

Question 13

What is the difference between a focal alveolar mass and nodule?

Answer 13

Nodule= less than 3cm 
Mass= greater than 3cm

Question 14

What are the most frequent causes of acute diffuse alveolar disease?

Answer 14

Bacterial pneumonia and pulmonary edema

Question 15

What is the extrapleural space?

Answer 15

Potential space between the rib cage and adherent parietal pleura

Question 16

Where does the pleural space extend posteriorly? Laterally?

Answer 16

Posterior= 12th rib 
Lateral= 10th rib

Question 17

What film is more sensitive for detecting a pleural effusion (lateral vs. PA)?

Answer 17

Lateral

Question 18

How can you tell the difference between pleural effusion and collapse with complete opacifiation of a lung?

Answer 18

Shift of the mediastinum is NOT seen in pleural effusion

Question 19

What are you seeing on a CXR of a pneumothorax?

Answer 19

Air on both sides of the pleura

*Note that this will mostly be seen in the APEX of the lung

Question 20

In LVH, how does the left heart border move on a PA film?

Answer 20

Laterally with anterolateral displacement of the cardiac apex

Question 21

In LVH, how does the left heart border move on a lateral film?

Answer 21

Inferoposteriorly

Question 22

How should the upper pulmonary vasculature compare to the lower pulmonary vasculature?

Answer 22

Upper should be smaller than lower

Question 23

What is “cephalization” of flow?

Answer 23

Upper pulmonary vessels larger or equal in size to smaller

*Indicative of CHF or mitral valve stenosis

Question 24

What are the stages of CHF on CXR?

Answer 24

1) Cephalization
2) Cephalization + pulmonary edema
3) All + Kerley B lines
4) Alveolar edema

Question 25

What are Kerley B lines?

Answer 25

Enlargement of the interlobular septa