So now let?s discuss one of the most common abnormalities seen on a chest x-ray.
And that is consolidation. So what is consolidation?
It?s a type of airspace disease so it causes filling of the alveolar spaces.
On a chest x-ray, it appears to have indistinct margins
and it presents as fluffy opacities that become confluent over time.
So if you take a look at this chest x-ray here,
this area that?s white is an area of consolidation.
Consolidation can occur from many different things.
The four major things are blood or hemorrhage within the alveolar spaces,
pus which is an example of pneumonia,
water which can fill the alveolar spaces as a result of pulmonary edema
and cells from carcinoma.
So let?s go over some signs of consolidation.
When you have an area of consolidation,
it appears white as we saw on a chest x-ray
and it may contain what we call air bronchograms,
so the air that normally surrounds the bronchi becomes opacified
and appears white while the bronchi remain air-filled.
So it makes them appear like black tubular structures within the area of consolidation.
So you can see here, this area is the area of consolidation in the left upper lobe.
Within this, you?ll see these linear, black tubular structures
that represent air bronchograms and this is one of the key features of consolidation.
So now let?s talk about the silhouette sign.
This was briefly mentioned in one of our introductory lectures
and it?s a very common radiological sign.
It occurs when two objects of the same density touch each other
so that the margin between the two can no longer be visualized.
So if you look here, there?s an area of consolidation involving the right middle lobe
and you can see that the right heart border is no longer visible.
So the area of consolidation is silhouetting the right heart border
and again, this occurs because the consolidation is of equal density to the heart
and now you can no longer see the margins between the two.
The spine sign is another sign that we can see with consolidation.
So in general, the thoracic spine gets darker as we get closer to the diaphragm.
However, if there is a lower lobe consolidation,
the x-ray beam has to penetrate the consolidation and the spine,
making it appear whiter. So this is an example of summation of shadows.
So when you have multiple shadows overlapping each other,
the area appears whiter than you would normally expect.
So pneumonia can be either localized or diffuse.
It can also be airspace or interstitial.
So there are a variety of different ways that pneumonia can present
and pneumonia is one of the most common causes of consolidation.
So let?s go over some signs of pneumonia and some patterns that we may see.
So these patterns are important to kind of keep in your mind
because they come up relatively often
and then you can see what the pattern represents.
So let?s take a look at this frontal chest x-ray.
What do you see here?
And as we go through this lecture, feel free to pause
and take a good look at the images.
So this is an example of right upper lobe consolidation.
The consolidation abuts the major fissure,
which produces a sharp margin inferiorly here and it involves the entire right upper lobe.
You can see that it silhouettes the mediastinum on the right.
So where do you think this consolidation is located?
We have a frontal and a lateral view in a patient that?s presenting let?s say with cough.
So this is an example of right middle lobe consolidation.
So on the frontal view, the right heart border is silhouetted
so that we don?t see it anymore and on the lateral view,
a middle lobe consolidation will overlap the heart.
So if you look here, the heart appears brighter than it normally would
and that?s because this consolidation that you see on the frontal view
is located adjacent to the heart anteriorly on the lateral view
and this is very typical of a right middle lobe consolidation.
Let?s take a look at this pattern.
So this patient is also presenting with consolidation.
Where do you think this consolidation is located?
Which part of the lung do you think it?s in?
So we have silhouetting of the right hemidiaphragm.
This is what a right lower lobe consolidation would look like.
So remember, to differentiate between a right middle lobe consolidation
and a right lower lobe consolidation on a frontal view,
the right middle lobe consolidation will silhouette the right heart border
while the right lower lobe consolidation will silhouette the right hemidiaphragm.
How about this chest x-ray?
Where do you think this consolidation is located?
So this is an example of a left upper lobe consolidation
which again silhouettes the left side of the upper mediastinum.
In this one, you can actually see some of the classic signs of air bronchograms,
and what do you see on this one?
So here we have silhouetting of the left heart border.
You can see that the right heart border is pretty clearly visualized
while the left heart border has a sharp margin here and then all of a sudden,
becomes somewhat hazy here. So this is an example of a lingular consolidation.
So the lingula is actually a portion of the left upper lobe if you recall.
However, it?s in the same location as the right middle lobe
so it?s somewhat a separate structure
although technically it?s considered part of the left upper lobe.
So what do we see here?
This is an example of left lower lobe consolidation.
So we have silhouetting of the left hemidiaphragm here.
So you can see a sharp margin here on the right.
However, the left hemidiaphragm which is normally visualized
through the heart is no longer seen. So this is a left lower lobe consolidation.