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Here's our first case. This is a patient who

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presents with acute chest pain.

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I'll have you look over these four axial

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non-gated CT images for about

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10 seconds or so and see

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if you can identify.

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the abnormality

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the images are shown from top left

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to bottom right in.

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Superior to inferior

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slice orientation

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so this is a challenging case but it's an important one and

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one that we want to make sure not to miss in the

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emergency setting or in any setting but especially in the

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setting of a patient who has acute chest pain and no

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prior diagnosis and the

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Imaging finding that I'll draw your attention to is

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this Crescent of low density tissue that

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separating

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the ascending aorta from the right atrial appendage

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a little bit lower we can see the crescent.

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persists on more inferior slices

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Right around the aortic root but is again between

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the aortic root and the right atrium and I'll

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make this observation that there

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really should be nothing separating the ascending aorta

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from the right atrial appendage. And when you see something you have

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to think about aortic pathology and that's what

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we have in this case.

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The Lumen of the aorta looks pristine, but

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this is an abnormality of the wall of

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the aorta and this is an acute intramural hematoma

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type A.

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type A indicates that

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the pathology involves the ascending aorta

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And as you all probably are aware. There are three principal

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types of non-traumatic acute

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aortic injury and they are acute aortic

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dissection.

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Intramural hematoma and penetrating atherosclerotic

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ulcer and these

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May coexist. This is

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a the intramural hematoma is probably the most difficult of

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the three diagnoses to make because there's no

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disruption of the intima almost by definition. We

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don't see a communication between the

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Moon and the wall.

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and to

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to remind you all of the distinction between Type

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A and type B type A.

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Means the ascending aorta is involved type B

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is everything else. So it's really type

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A or not type A. So, although it

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was confusing for a long

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time and and

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Even in our literature the aortic

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Arch is not clearly defined or sometimes is

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defined as type A if the dissection starts in

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the aortic Arch or an it is

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a tight bee lesion not

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type A to be type A. It has been involved

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the ascending order.

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also add a comment about

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type A intramural hematomas

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there are findings.

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That we can see at Imaging that are associated with higher risk of

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complications.

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In particular if the outer wall to outer wall

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diameter here characterized by this Black Arrow.

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Is greater than 4.8 centimeters and we generally

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just make this five centimeters for practical

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application. It's greater than

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five centimeters. It confers worse prognosis.

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If the hematoma thickness here

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shown as this double arrow orange arrow

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is greater than 10 millimeters.

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Then we consider that a higher risk lesion. There's

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also something called luminal compression ratio,

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which is the ratio of the short axis

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of the Lumen here the the double-headed red

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arrow.

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Divided by the long axis of

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the Lumen here the double arrowed blue

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arrow if that's less than

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point. Seven five. It indicates significant compression of

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the Lumen and that's associated with worse outcome.

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So sometimes cardiac surgeons

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will elect not to operate on this

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operative type a lesion.

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If the morphology of the intramural hematoma is

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favorable and they may just watch this

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dissection. Very close. I'm sorry this intramural hematoma

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very closely.

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But these are known to heal in

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some patients so important to provide some

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additional information.

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On the metrics of the hematoma.