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Alright.

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This session of the cardiopulmonary

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imaging will be on atelectasis.

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We'll be doing it in two parts.

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And, um, this one we're going to review mainly

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the imaging findings and types of atelectasis.

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And we'll emphasize a little bit

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about the importance of the presence

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or absence of air bronchograms.

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Yes, Atelectasis can have air bronchograms.

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And we'll, uh, we won't talk too much about

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the, uh, fever myth or the atelectasis

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versus consolidation enhancement.

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We'll do that in session two.

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So just to show you the morphologic patterns

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as we go through all of this, this one will

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be in the increased opacity atelectasis.

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Now, atelectasis really is just sort

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of a loss of volume within the lung.

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And what does it look like?

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Usually radiographically, or on CT,

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it's linear, usually with sharper margins.

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It can be band-like, and on the radiograph,

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or so, it can be triangular in shape,

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almost always radiating from the hilum.

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That's a pretty good clue.

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It just radiates to the hilum.

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You might see a dense hilum.

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That's usually atelectasis within the

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superior segment of the lower lobe.

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Um, smooth margins are important.

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If you see margins that are indistinct,

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You start wondering, Hmm, is that

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a consolidation slash aspiration?

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The most important imaging feature

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is deviation of the fissure.

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So when the fissure is

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deviated, there's volume loss.

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So you have to know the normal

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position of the fissures, the major

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fissure, and the right minor fissure.

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Another sign is crowding of the vessels.

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Vessels are separated.

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The bronchi are separated when you lose volume.

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They get close together, so they crowd up.

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And when you don't have any air bronchograms,

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and you can't see the airways,

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that almost always, not every time, but almost

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always means there's an obstruction to the

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bronchus with fluid and loss of volume.

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Okay, so you got to know where the fissures are.

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Major fissure, minor fissure.

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Minor fissure, that's the right side.

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The left side is just the major fissure.

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When you see a fissure like here,

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the fissure will always be sort of

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this sharp margin, it's deviated.

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And when it's deviated,

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by definition, there's volume loss.

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On a radiograph, this is a pretty standard

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appearance, you'll kind of see this

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sharp kind of triangular kind of opacity.

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Usually, it's infrahiler and it may spare

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what looks like the more periphery.

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That is almost always going to be atelectasis.

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So saying, well, it could be atelectasis

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pneumonia, you're like, well, imaging-wise,

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this is most consistent with atelectasis.

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You could say if the patient has a low-grade

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fever, you could consider maybe aspiration.

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Something like that, but that's atelectasis.

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Classically, very smoothly.

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Marginated, radiating from the hilum.

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Band-like opacities, very standard.

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This is sharply marginated, radiates to the hilum.

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Notice the major fissure, which

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should be here, is deviated.

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This is atelectasis.

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There's no differential.

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It's not atelectasis could be pneumonia.

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No, no, no.

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This is atelectasis.

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So, what are the major types?

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Well, there are four or five types,

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and if you want to divide things, obstructive.

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So, the central obstruction, no air bronchograms.

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Passive means sort of the hypoventilation

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or pleural effusion or pneumothorax,

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which is compressed the heart.

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Compressive is bulla, abscess, or lung mass.

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These, the difference between passive

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and compressive, well, it really isn't.

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It's just Hypo or passive is more plural.

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P for plural and compressive is within the lung.

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So if you have a large cyst that

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compresses the lung, it's compressive atelectasis.

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Um, you can just call it all passive if you want.

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And the last one is izing or the scarring form.

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So when things scar, they have volume.

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So as things scar, they retract.

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Okay?

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The last three tend to have air bronchograms.

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The first one does not.

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So let's go through a few.

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New onset hypoxia.

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Well, there's complete

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opacification of the left lung.

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Uh, you don't see the heart, right?

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Because the heart got pulled over.

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The mediastinum is pulled over and there's

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the bronchial cutoff sign right there.

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No air bronchogram.

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Volume loss, no air bronchograms

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usually means obstructive.

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Okay?

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Another patient.

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There's deviation of the mediastinum to the

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right, there's complete opacification with

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audio bronchograms, a mucous plug within

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the bronchocenter medius is present,

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and you can see on the CT that, yeah, this,

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the, because of the mucous plugging, these

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bronchi fill with fluid, and you cannot see

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them here, you just see the volume loss.

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Mediastinal shift, deviation of

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the fissure, which you see here.

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Okay, this is a left upper lobe collapse.

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This is a pretty characteristic sign,

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just to make sure you know about it.

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It's called luftcicle.

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And when it goes, the major fissure,

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which normally is here, is deviated anteriorly.

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There are no air bronchograms.

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This is a post-obstruction to the left upper lobe.

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with left upper lobe collapse.

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And you can see the air ring

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right around the aortic arch.

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That's actually a fairly characteristic

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appearance of left upper lobe collapse.

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Now, When the fissure deviates, it should

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deviate in a concave or straight manner.

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Whenever it deviates and there is

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a convexity, that isn't normal.

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That's called the goldenness sign.

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It's a convexity here that basically the

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fissure is going, is lying over a mass.

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like a blanket.

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And you see that convexity of the

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mass that tells you, Hey, this

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patient has right upper lobe collapse.

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There are no air bronchograms obstructive.

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There's no right upper lobe bronchus here.

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And in that region is the convexity of the mass.

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Just to let you know, too, juxtaphrenic peak, uh,

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in books is from the inferior pulmonary ligament.

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That is absolutely false.

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It is simply represents tugging of the hilum,

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which lifts up on the inferior accessory fissure.

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All right, CT scan, same thing.

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There is the deviation of the fissure.

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No air bronchograms, but notice the convexity.

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There's a convexity, there's a mass here.

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So this is a right upper lobe mass

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with post-obstructive atelectasis.

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This is a form of passive atelectasis.

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There's pleural effusion and it's kind

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of compressed the left lower lobe.

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Notice the air bronchograms are

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crowded together and they're open.

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This is not post-obstructive.

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This is simply atelectasis from the pleural fluid.

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Um, if it's pleural fluid like

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empyema, you can see the compressive

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atelectasis here or passive atelectasis.

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And this is more of a, um, a cavitating mass.

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which has also caused somatolexis.

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You can call them both passive if you want,

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but this one's officially called compressive

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from the lung, passive from the pleura.

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Uh, a patient with hypoventilation has

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some linear areas, little triangular

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and linear areas of increased opacity,

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relatively sharply marginated findings.

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They're characteristic for, uh, at,

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uh, atelectasis from hypoventilation.

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How about this one?

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This patient has a number of air bronchograms

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and you can see they're crowded together.

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Would bronchoscopy help this person?

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No, because there's nothing

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centrally obstructing it.

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So if you have atelectasis and there are

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bronchograms, it's not from central

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obstruction and bronchoscopy will not help.

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little tidbit.

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And then one of the other patients, chronic

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histoplasmosis is an example, radiation therapy.

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This is the so-called scarring or secretizing.

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And you can see where the hilum are pulled up

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kind of like old man pants in Florida, real high.

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And you've got this volume loss

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and architectural distortion.

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The fissures are all deviated.

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This is a chronic form of volume loss, right?

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Atelectasis, when you have scarring or fibrosis.

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The lung retracts.

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So, that's it for the atelectasis session one.

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When you're looking, the synchronom,

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if you wish, is deviation of the fissure.

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Whenever the fissure is

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deviated, there's volume loss.

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Um, atelectasis without air bronchograms,

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Almost always post-obstructive. Look for

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any abnormal convexity or the so-called

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golden nest sign that says that may

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be a mass and aex with their bronchoscopies.

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Well, their bronchograms are diagnostic

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and it also tells you the bronchi is open.

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And that is it.

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So join me for Atelectasis session two next.

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Thank you.