0:00

And since we are talking about Travelers the next case I

0:03

wanted to show you was a patient who had CT Imaging

0:06

to assess for suitability for Tower. This

0:09

was a 62 year old male had aortic stenosis.

0:13

So I'll play these axial CT images for you. We're

0:16

going from the cranial to the caudal aspect and it

0:19

might feel like it's going away or the images are moving

0:22

too fast, but I will play it a few times for you.

0:25

We going now from the bottom up.

0:28

And what you noticed is dense coronary arterial calcification, but

0:31

I want you to pay particular attention to

0:34

the aortic Arch citedness and the branching

0:37

pattern. So think about what kind of art normally

0:41

are. We looking at.

0:43

And here I'll play this once again.

0:47

So here are the arch vessels this looks predominantly like

0:50

a right-sided arch and I'll show you some still images as well.

0:55

In just a little bit.

1:00

So here is the ascending aorta now you're getting

1:03

to a very dilated esophagus here. This is

1:06

the right-sided arch here is the left subclaven left

1:09

carotid.

1:11

white carotid and rights of Clavin arteries

1:15

Now this patient like I said was being referred to town

1:18

for Towers. So it's a very good idea to look at the aortic root

1:21

and see if you can get orthogonal images to the

1:24

aortic root.

1:25

And since we do this retrospectively gated you could

1:28

actually see the cinemotion of the aortic valve itself.

1:31

So as we going down you can see this is a bicuspidiotic bound.

1:34

It doesn't have those three leaflets. And in

1:37

fact, one of the leaflets is almost immobile. So

1:40

this patient that really goes

1:43

with a history of aortic stenosis we have in this patient.

1:48

Turn our attention back to the aortic Arch branching abnormality. We

1:51

were talking about.

1:53

So here are some images and I'm showing you four representative images

1:56

which are actually enough to make the diagnosis. So

1:59

we start from the top here are the right

2:02

karate rights of Clavin left carotid left subclavian arteries.

2:05

This is the right-sided arch. We are looking at here's the

2:08

left. So Cleveland and left carotid and I

2:11

will point it out if the movie was too fast for

2:14

you that the left foot leaving artery.

2:16

Was pretty close to the arch, but it

2:19

never quite connected.

2:21

So the left subclave and artery did not connect to the arch or

2:24

this aspect of the arch at all.

2:27

This is where the vessels become confluent the left carotidants

2:30

of Kevin and you can see they are arising from the arch at

2:33

this point.

2:35

So let me show you a volume rendered images as

2:38

well. So here is the right-sided arch and

2:41

let me play it for you.

2:44

So here's the right-sided arch.

2:47

And you can see that there is a little divertic limb

2:50

coming off the right Arch, which comes very very close to

2:53

the left of Cleveland artery, but the left of Cleveland artery and

2:56

the left carotid arteries arise from

3:00

the arch from somewhere here.

3:03

Here are again, the axial images to show you exactly what we're

3:06

looking at. I can play the movie once more but this

3:09

brings up a question and this is often a question. You will encounter. In

3:12

fact, I've started seeing these

3:15

kind of cases with our genomics in patients

3:18

who just have a routine aorta for some other reasons or

3:21

just a chastity for fun for any reason.

3:24

It's very important. When we look at these cases. We determine

3:27

in our minds is this vascular ring or not?

3:30

So, please go ahead and answer this question. What do you think and it's

3:33

a 50% chance of getting it right? So I would encourage

3:36

everybody on this call to try take a

3:39

stab at this question.

3:41

What would you think is this a vascular ring? Yes

3:44

or no?

3:46

Remember that this patient has a dilated esophagus.

3:50

We are looking at a right-sided arch and then

3:53

we will come to a more specific question as to what?

3:57

What pattern of aortic Arch this might be?

4:01

So most people think that this is not an aortic Arch.

4:04

This is not a vascular ring and I

4:07

will reveal the answer in a few minutes, but let's go

4:10

to the next question.

4:13

Because this is really the main question which kind of drives your

4:16

answer to the prior question as well. What do you

4:19

think is the diagnosis do you think it's a right option?

4:22

Actually if you don't mind if you can bring up the question once

4:25

again

4:26

Is this the right arch with mirror image

4:29

branching? Is it a right-art with apparent left

4:32

subclavian artery or is it a double aortic Arch?

4:36

And then we will answer both these questions together.

4:41

So, please go ahead and vote for one of these options.

4:46

Alright, so this is excellent.

4:49

Actually majority of people think it's a

4:52

right arch with mirror image branching.

4:54

A third of people think it's a wiotic arch and really

4:57

these are the two main differentials in this case. I'm really glad

5:00

we were thinking along these lines. Nobody really thought

5:03

it's a right arch with aberrant laps of Clavin artery. That's absolutely

5:06

right. So, let me close the poll results.

5:10

And that's absolutely right. This is

5:13

this is not going to be a right arch with aberrant laptop Cleveland because it

5:16

really did not originate as an apparent

5:19

vessel at all.

5:21

So the real differential here is could it be a write-art with

5:24

mirror image branching or a double Arch? The answer here is a double aortic

5:27

Arch and in the next few slides. My Endeavor would

5:30

be to try and prove why I say it's a double Arch.

5:34

And again now if we go back and revisit question number

5:37

one the fact that we are seeing it's a double aortic Arch

5:40

leads us to believe that this is a vascular ring. You also

5:43

noticed that this patient had esophageal annotation.

5:48

So as we answer this question, I think it's a good time to

5:51

reflect on what constitutes a vascular ring.

5:54

It's an abnormal encircling of the trachan esophagus by

5:57

aortic branches. And the key thing here is they could

6:00

be patent or they could be remnants.

6:03

So if they are Peyton they are very easy to visualize on

6:06

CT. But if you have remnants, then you

6:09

can't really directly see the remnant on CT, but you

6:12

have to identify it by means of some kind of indirect signs.

6:16

And there are 3DS. Very easy to remember. There are

6:19

3DS that help you identify avascular ring.

6:23

So is there reductors opposite the side of the arch? Is

6:26

there a diverticulum or rising from the approximal descending

6:29

aorta? And this is what we saw in this case.

6:32

Or if you have a descending aorta approximately that

6:35

courses opposite the side of the arch any of

6:38

these three indicates that the patient may have

6:41

a vascular ring.

6:43

So let's go back in this particular case. We

6:46

saw diverticular memorizing from the proximal aorta

6:49

and this is where you see it. So this divertic limb

6:52

is a clue that there might be a vascular ring.

6:56

And if you use a little imagination you can see how this

6:59

is actually the attractive portion of the left Arch.

7:02

The left Arch is just much smaller than the

7:05

right-sided arch and there is a focal atresia in

7:08

the left aortic Arch.

7:10

The other big clue that I find very very useful when

7:13

I'm evaluating cases like this is to look

7:16

at the four artery sign.

7:18

So imagine when a patient has two arches the origin of

7:21

the vessels is going to be very very symmetric from the arch and

7:24

if you were to try and connect these vessels, you can see how they

7:27

form a trapezoid so symmetrical trapezoid appearance

7:30

is a sign of wiotic arch.

7:34

And just for contrast. I wanted to show you a patient or

7:37

just a normal individual who has a left Arch

7:40

a normal branching.

7:41

So imagine when you have a left Arch a normal

7:44

branching the right-sided arch invalutes, there is

7:47

no Remnant, it just invalutes and disappears and when

7:50

it does so if you look at the arrangement of these vessels, this

7:53

does not have this kind of a symmetric trapezoid

7:56

appearance because the nominate vessels go a

7:59

lot more anterior than the other vessels.

8:03

So again, remember the two key features.

8:07

That fact that we cannot see a credit cards directly

8:10

either by ctrmri. Don't expect to see

8:13

a fibrous cord or something to indicate in a credit

8:16

card. You're not going to see anything. But what you want

8:19

to really see is some kind of indirect sign to

8:22

indicate its presence.

8:25

like we saw a lot of people mistake it for

8:28

right arch with mirror image branching and that is

8:31

that is definitely true because it can be easily mistaken for

8:34

a right arch with mirror image branching.

8:37

The two key features remember in this particular case where

8:40

the diverticulum from the proximal descending aorta and secondly

8:43

the symmetric origin of the vessels. So

8:46

the four artery sign.

8:49

moving on to the next case

8:51

and this is an interesting one. I still remember I was reading

8:54

the chest x-ray on this patient. So imagine I

8:57

can't remember what the precise history was, but I would imagine

9:00

if I had to just take a guess it would happen something

9:03

like shortness of breath.

9:05

So when you're looking at this x-ray, you can see that the heart

9:08

is big. In fact, the right atrium was big you

9:11

can see the right ventricle. It has significant amount

9:14

of contact with the sternum indicating right ventricular enlargement.

9:18

The Apex is however the LV type of Apex and in

9:21

fact, you can see that the left ventricle is enlarged as well. So there's

9:24

clearly Garden cardiomegaly going on.

9:27

something that caught my attention at the time I was reading the X-ray

9:30

was

9:31

right here. You kind of signed opacity related or

9:35

in this particular region. So as we normally do

9:38

you want to look for any prior Imaging you can find or

9:41

you look for any cross section Imaging you could compare it to

9:44

so luckily this patient had a CT abdomen.

9:48

And I want you to look at the CT abdomen. So I

9:51

just pulled it up for comparison when I was reading the chest x-ray.

9:55

Unfortunately, it didn't go too high. So we couldn't really correspond

9:58

it or I couldn't really correlate it

10:01

exactly with the abnormality. I was seen on the X-ray but

10:04

looking at the size of this particular vein. I started

10:07

feeling that maybe this was just a venous structure.

10:11

Having said that I would like you to just look

10:14

at the CT as a whole and see if you can pick up anything else

10:17

on the CT.

10:20

Anything that is that maybe interesting or what?

10:26

Suggest doing something different for the patient.

10:29

So once we've done it a few times.

10:32

Let me show you the question for this question.

10:35

So what is the next best step in this

10:38

particular exam? Let's say you looked at that x-ray.

10:41

Would you like to do a non-gated contrast enhanced CT?

10:45

Would you like to do a gated contrast enhanced CT?

10:48

Would you like to do a non contrast CTE chest

10:51

or would you think no further investigation since in all

10:54

likelihood what we were seeing on the X-ray?

10:57

Seem to be just a vascular structure.

11:01

So let's wait for everybody to think

11:04

about that question again. So remember the X-ray we

11:07

saw.

11:08

A questionable finding and then when we

11:11

were trying to correlate it, we couldn't really correlate it very well

11:14

on the CT because it didn't cover the abnormality well

11:17

enough.

11:18

But I want you to think about anything additional you

11:21

may have seen on the CT of the abdomen that would

11:24

guide your next step.

11:28

All right.

11:30

That is excellent. So everybody thought about the Gated

11:33

contrast enhancy tea and that is indeed the

11:36

correct answer in this case. So I'm pretty

11:39

proud of the fact that everybody picked up that finding I was

11:42

looking at and let's revisit it one more time.

11:44

So when I was comparing it to the chest

11:47

x-ray, I definitely saw this and I thought okay, this doesn't seem to

11:50

bothersome to me. But what was catching my

11:53

attention was the left AV Groove.

11:55

So here this is what was bothering me and when

11:58

I was

11:59

Let's run the movie again. You can see there is too

12:02

much happening in the left TV Groove.

12:04

And I was quite concerned that the patient's coronary

12:07

arteries even on this non-gated CT exam.

12:11

Were dilated which made me worry about a

12:14

particular diagnosis and I suggested a gated

12:17

contrast enhancy tea. So, let me show you what happened.

12:20

The patient came back got a gated

12:23

contrast enhanced CT.

12:25

And now I'm going to run through this.

12:27

Movie we're going from the top to the bottom.

12:31

And what you're starting to see here in the left AV group

12:34

is a very very dilated left circumflex

12:37

artery and not only is the dilated. It's markedly torturous

12:40

as well.

12:42

So we're running it one more time. You can see the right coronary artery

12:45

is actually pretty normal in caliber.

12:49

Here is the left circumflex artery. That is markedly. Torturous.

12:52

This is where it

12:55

Comes in and let's run it one more time. Here is

12:58

the left Main.

12:59

This is the LED here. By the way, this structure that

13:02

has a much more normal caliber. The LED is

13:05

normal, but the left means circumflex are

13:08

markedly dilated.

13:10

And you can see this is the coronary sign is that is

13:13

also quite dilated and very intimately related to

13:16

the circumflex artery.

13:18

So once you've seen this finding here, let's look at

13:21

the volume rendered images. So we looking at the aortic root

13:24

here.

13:25

This is the left anterior descending artery. It's running

13:28

between the right ventricle and left ventricle. Here

13:31

is the right coronary artery and these seem pretty unremarkable.

13:35

But here is a very very dilated left main artery

13:38

and this is the left circumflex coronary artery.

13:41

So let me spin this around so you can see it from another perspective

13:44

as well again, here is the RCA. This is

13:47

the coronary sinus and this is a very markedly dilated

13:50

circumflex artery.

13:56

So here it is. This is the coronary sinus very

13:59

much very dilated and torturous left

14:02

circumflex artery.

14:05

So the question is what do you think is the most likely diagnosis?

14:08

What do you think? It's atherosclerotic coronary artery. Aneurysm

14:11

Kawasaki disease pressure is

14:14

disease.

14:15

or a coronary artery fistula

14:19

So think about the dilatation of the coronary artery think

14:22

about the dilatation of the coronary sinus.

14:25

And What entity would tie the two

14:28

in together?

14:31

Okay. Can we see the answers of the pole, please?

14:36

And that's excellent. Everybody thinks it's a coronary artery facial and

14:39

I totally agree with you. So

14:44

this is indeed a coronary artery fistula where the circumflex artery

14:47

was.

14:48

Communicating abnormally with the coronary sinus leading

14:51

to its annotation and just to review what

14:54

is a coronary artery fistula. It's basically a connection between

14:57

a coronary artery branch and it can communicate with

15:00

a cardiac chamber or a Venus or

15:03

arterial structure like coronary sinus SVC pulmonary

15:06

artery or rain.

15:08

In this particular image what you're seeing is this is the left anterior

15:11

descending artery. The arrow is pointing to a very dilated LED

15:14

proximately.

15:16

But soon after it gives off this very torturous branch, which

15:19

was communicating with the pulmonary artery and after

15:22

it gives off the branch the caliber of the LED significantly

15:26

drops. So this is a very very useful feature of coronary

15:29

artery fistula and these tend to be congenital in

15:32

most cases. So when you

15:35

think about the left circumflex to coronary sinus fistula, I

15:38

want you to consider what are the problems with the fistula?

15:41

Could have the question please for the polling,

15:44

please. It's does it lead to a left to

15:47

right shunt in this case. Would it lead to Steel phenomenon or

15:50

both?

15:58

Alright, so, let's see if we can get the results of the

16:01

pole.

16:02

Yeah, that's excellent. So it indeed does

16:05

lead to both the left to right shunt because you have the coronary artery

16:08

ending in the right side of structure. It also leads

16:11

to steal phenomenon because instead of the coronary

16:14

artery perfusing The myocardium it now is running

16:17

off into this coronary sinus. So it's depriving The

16:20

myocardium of its blood supply so that is

16:23

indeed the correct answer.

16:26

So like I said hemodynamics can be shunt and

16:29

that could lead to ischemic symptoms.

16:31

These patients often have heart murmur and

16:34

they could have a shunt depending on where the fistula

16:37

really drains into.