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Hey everyone, this is Mark and we're

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moving on with pulmonary hypertension. We're going to dive a little

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bit more into the chronic thromboembolic sort

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of world.

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And it is something that is often looked

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for.

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And of course pulmonary CTA is a wonderful way

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to do it. We're gonna look through the Imaging appearance of

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chronic thrombolic disease also called thromogenic arteriopathy

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and we'll review how

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to distinguish the mural thrombi from Hyler lymph

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nodes because that would be kind of tricky by the way.

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And then we'll kind of look at the Mosaic lung attenuation.

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This is commonly attributed to chronic thrombolic disease,

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but I want to show you that again multiple

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etiologies lead propulmonary hypertension

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lead to a common final pathway. There are other things that cause

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pulmonary hypertension that also can give you Mosaic lung

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attenuation.

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Just one quick review. We always look for this.

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But it is in fact the least common all Commerce

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for pulmonary hypertension.

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So

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we do look for it. This is a mural thrombus. This is a patient

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who's pulmonary artery is clearly larger than the ascending

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aorta. You can measure it. I think it was like four centimeters this

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so this would be pulmonary hypertension.

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secondary to chronic thrombolic disease

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pretty straightforward

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mural thrombi are adherent to the wall

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and tend to be of a lower density. This is

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key. There is no expansion of the

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vessels.

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Expansion of the vessels is seen in the acute setting of

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embolus chronically. There is no expansion

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of the vessels.

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Okay.

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There may be webs or areas of stenosis and

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strictures present within other pulmonary arteries.

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So if you see mural thrombus, you're

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not sure look for evidence of webs or stenosis.

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This is reflecting prior thrombolic events.

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You can look for Mosaic. Lung attenuation always assess the

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pulmonary artery size and I'm going to give a shout out for reformation

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here the sagittal and coronals even oblique.

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They can really help you sort of tease out

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whether this is real web. This is real mural

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thrombus or is it a higher lymph node?

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so

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these to me are straightforward.

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They're adherent. They're low density. These are mural thrombi.

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They tend to have up two singles.

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Lymph nodes like this tend to be a little

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higher density.

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Okay, and remember higher lymph nodes

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don't have that circular or oval appearance

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that we used to see, you know in the axillary the neck

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the abdomen the inguinal area.

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They tend to be a bit more amorphous soft tissue

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kind of fitting along the bifurcations.

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This patient clearly had some pulmonary artery enlargement. The pressures

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were elevated. There was straightening in the interventricular septum.

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And yes, they did have Mosaic lung attenuation areas

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of higher density alternating with areas of

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lower density.

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now

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How does it develop? Well a lot

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of different theories? Some are pretty good here and I put down

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the ones I thought were most likely.

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Actually necessary need multiple embolic events to

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develop it and in some rat studies, you can induce

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pulmonary hypertension just from one endless and why

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maybe the capillary endothelium, yeah is

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not fully loaded with

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some fibrolytic component to fully break down the clot. It's

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relatively resistant. Maybe you know,

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the thrombus is more resistant in itself from

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what it's made.

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Not sure.

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But when you do see this mural thrombus and

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you see the pulmonary arteries are enlarged this is thrombogenic

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arteriopathy or chronic thrombolic disease,

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one of the things about chronic thrombolic disease,

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even though it's not very common.

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All comers right from it does 10 to

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be a relatively common cause for more

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severe pulmonary hypertension.

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So if you see webs like this.

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That just says hey this person has had prior

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thrombolic events. The pulmonary artery

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is normal in this patient. There's no evidence for interventricular septal

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straightening. There's transient Interruption

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of contrast small web here. So although they've

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had prior events that doesn't necessarily

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mean they're going to develop pulmonary hypertension.

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Now the patient with webs and some calcification simply means

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they've had prior events, but you want

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to pause and take a closer look at the pulmonary arteries and

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the right heart.

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Now how do you tell mural thrombus from Hilary lymph

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nodes key here is one is density and two

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are the borders and the inner border

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of a mural thrombus tends to be lobulated the

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outer border against the pulmonary artery wall tends

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to be very smooth.

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The lymph node, the inner border along the pulmonary

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artery wall is smooth. The outer border tends

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to be lobulated.

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Okay, this would be a lymph node notice how the

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inner border is smooth and the outer border is lobulated. It's

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also a little bit higher density.

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This is a mural thrombus. The inner border is

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lobulated. The outer border is smooth.

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Okay. This is a lymph node outer border

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is lobulated inner border smooth higher density

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than the mural thrombus and

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this patient also had concurrent webs

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clearly. This is

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chronic thrombolic disease.

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Another patient. This is where Reformation can be helpful is that

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you have some mural thrombus here smooth outer border

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lobulated inner border, but you also have a number of lymph nodes

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here.

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This patient is another lymph node lobulated inner

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border smooth inner border for the lymph node.

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Lobulated inner border for the mural thrombus

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high density lymph node, another patient with

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a lymph node lobulated outer border.

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Mural thrombus lobulated inner border, okay.

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So I know that can be a little tricky. Now remember Reformation are

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also helpful because it's like well, wait a minute. Is that a small

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emblest or a web? Well, you look in the Reformation. No, it's

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linear. That's an artifact anything

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linear like that artifact. No

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expansion the vessels that's an artifact.

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Okay, what can you do with these patients

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with mural thromb by the central?

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Well if they are a surgical candidate.

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Then get something called.

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Pulmonary thromboland artarectomy now, this is

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a very aggressive surgery, but you know

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the patient survives.

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They can have a pretty good outcome, but who

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gets it? Well, it's the central larger kind

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of mural thrawn by patients. Not

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the small tiny peripheral ones.

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Not the small tiny performance. It's the larger ones.

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So Mosaic long attenuation, this is

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a reflection of advanced pulmonary

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hypertension. Remember the common final pathway.

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It often gets taught that it is more predictive for chronic

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thrombolic disease.

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You know, I would definitely be looking for chronic thrombolics

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anyway, but I've seen this in a number

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of patients with Advanced pulmonary hypertension because remember what happens

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is there's a patchy obliteration of

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the pulmonary vessels.

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So there are areas of the wider areas where you

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have the large more normal pulmonary vessels and the darker

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areas where they're destroyed or obliterated. And so

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that will give you a mosaic lung attenuation. Even if

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it wasn't from chronic thrombolic disease.

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40 year old female has large low

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bar arteries has the right ventricular hypertrophy and was

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diagnosed on VQ scan with chronic thrombo-embolic disease

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and pulmonary hypertension from a VQ scan four years

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ago.

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This was the VQ scan ventilation is fine.

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Yeah, this is a high probability.

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Does that mean this is chronic thrombolic disease?

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Well, they did a CT angio and there was nothing here that

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look like mural thrombi webs nothing.

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They did have a pulmonary artery pseudo aneurysm from

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prior pulmonary artery catheterization which popped it. But yeah,

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nothing here.

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so I mean

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There's no mural thrombi. Even if this was peripheral

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pulmonary artery hypertension from thrombolic season

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and kind of treat them any different, but I would submit to

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you that this patient never really had that

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When you look at the lungs reconstructed, you

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see this widespread vasel Mosaic lung

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attenuation.

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Well, we kind of did a fun 3D rendering if it's

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you know more bright orange. There's more flow if

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it's a dark orange is less flow that compare that

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with the VQ scan.

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so, you know when you get patients with Mosaic lung

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attenuation by definition

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VQ scan will be high probability.

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Okay, that's why I don't really think

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the VQ scan has used. There will be pulmonologists who

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will adamantly disagree but in the

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end.

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You do the Viki scan. You're still gonna do the right heart

9:30

cat. You're still gonna do the CT pulmonary. Angio. Both

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of those can answer the question. So I don't really

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know what you're using it for.

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So in summary chronic thrombology, although an uncommon

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cause of overall pulmonary hypertension is one

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of the more common causes for severe.

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To differentiate neural thrombody look at the inner lobulation and

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the density from Hyler lymph

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node, look for outer wall or border lobulation

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and a higher density. Okay and Mosaic

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long continuation occurs, almost always

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in the setting of advanced pulmonary hypertension no matter

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the etiology.

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Thank you very much.