1.1: Lung patterns

Question 1

What are the 4 lung patterns?

Answer 1

• Alveolar
• Interstitial
• Bronchial
• Vascular

These arise from the 4 things we have in the lungs (air in the alveoli, airways, interstitium, and blood vessels).

Question 2

Which lung pattern is shown here?

Answer 2

Alveolar pattern
This pattern creates a soft tissue-like opacity within the lungs; think of it as heavy fog obscuring structures.
There is border obliteration (we can no longer clearly distinguish the cardiac silhouette).
We can still see air bronchograms because alveolar diseases spared the airways.

Question 3

Which lung pattern is shown here?

Answer 3

Alveolar pattern
There is characteristic border obliteration

Question 4

We can see tramlines and donuts. Which lung pattern is shown here?

Answer 4

Interstitial
This is like looking through mist or a lace curtain; structures are not obliterated, but are greyed-out.
Donuts and tramlines = abnormal thickening of the airway (bronchiole) walls -> bronchial pattern

Question 5

Which lung pattern is shown here?

Answer 5

Mixed alveolar and interstitial
We can see air bronchograms.
There is border obliteration of the diaphragm.
There is a generalised increase in radiodensity throughout the lungs.

Question 6

Which lung pattern is shown here?

Answer 6

Mixed alveolar and interstitial
This is from a dog with Angiostrongylus vasorum.

Question 7

Which lung pattern is shown here?

Answer 7

Interstitial
There is generalised greying-out of the lungs but no border obliteration or air bronchograms.

Question 8

Which lung pattern is shown here?

Answer 8

Alveolar
This is limited to the diaphragmatic lung lobes.
There is border obliteration of the diaphragm.

Question 9

Which lung pattern is shown here?

Answer 9

Interstitial

Question 10

Which lung pattern is shown in Case 1? Justify your answer.

Answer 10

Interstitial
There is a diffuse increase in radiodensity (greying-out, lace curtain) but no border obliteration

Question 11

Which lung pattern is shown here?

Answer 11

Interstitial pattern
There is a generalised increase in radiodensity but no border obliteration.

Question 12

Which lung pattern is shown here?

Answer 12

Nodular interstitial pattern
This is associated with metastatic lung tumours.

Question 13

Which lung pattern is shown here?

Answer 13

Diffuse interstitial
This is associated with metastatic lung tumours.

Question 14

Which lung pattern is shown here?

Answer 14

Bronchial
We can see the tramlines of dilated airways that don’t taper

Question 15

Which lung pattern is shown here?

Answer 15

Bronchial
These are bronchiectatic airways (dilated and weak)
Hilus of the lungs is a good place to look

Question 16

What shape can you identify on this radiograph and what does it indicate?

Answer 16

Donut = thickened airway wall. Consistent with bronchial lung pattern. Classic finding in Canine Chronic Bronchitis, for example.

Question 17

What finding is circled here?

Answer 17

Air bronchogram

Question 18

What is an air bronchogram and when would you see it?

Answer 18

Air bronchogram: the phenomenon of air-filled bronchi (dark) being made visible by the opacification of surrounding alveoli.
Air bronchograms classically appear with alveolar disease (i.e. alveoli get filled with something).
However, we can also see them in interstitial disease, e.g. where there has been compressive atelectasis and crowding of tissue around open airways.

Question 19

Which lung pattern is shown here?

Answer 19

Interstitial

Question 20

What finding is shown on these radiographs?

Answer 20

A single mass (pulmonary neoplasia)