0:00

Okay, this next case is a 67 year

0:04

old woman who has a history of chest pain who came

0:07

in for coronary CT evaluation in this patient

0:10

and also having severe disease.

0:12

So we'll start again with the axial images.

0:16

And as we go down.

0:19

We know this is this may be tough to pick up on axial. But

0:22

you know over time I think after reading all these CTS

0:25

you'll start to recognize.

0:28

the connection between the LED and the

0:31

circumflex and the cusp is

0:33

not normal here. You're not really

0:36

seeing a good left Main.

0:38

And so this is concerning for

0:41

a left main stenosis. Now the

0:44

big thing that you have to think about.

0:46

As another possibility here is that there's some motion artifact

0:49

that's blurring this region and that can absolutely simulate

0:52

us stenosis.

0:55

If you look around at the neighboring structures, though,

0:58

usually if you have a blurring artifact it's going to affect.

1:01

other structures as well

1:04

and you can see that the wall of the aorta is

1:07

very clear.

1:09

Same with the left atrium same with the LED.

1:13

So maybe this isn't blurring artifact after all

1:16

so we'll keep our eye on that subsequent CPR images.

1:19

Now if we continue down the LED, I'm

1:22

going to zoom up. It's kind of a small vessel

1:25

on this patient.

1:27

You're gonna see and this is a normal

1:30

looking very proximal idea and they may right away get into this calcified plaque,

1:33

but we do see a fair bit of contrast getting

1:36

by and it doesn't look like there's a significant stenosis.

1:41

And then more distally.

1:44

We see even more calcified black.

1:47

But again with some decent looking contrast movement.

1:51

Now here's where we get into trouble with cardiac CT.

1:54

And and that is when we have heavily calcified lesions

1:57

in small vessels. And this is a good example. You can

2:00

see this diagonal Branch here. We basically have

2:05

a lumen and calcium and it's honestly hard to tell

2:08

where one begins in the other ends.

2:10

And then beyond that you see that you lose the

2:13

Lumen and there's this Gap and then you

2:16

get into the more distal diagonal Branch here.

2:20

So sometimes we can use the

2:23

Calcium score to kind of help us to

2:26

sort of Orient ourselves to where the diseases. So in

2:29

this case, here's the corresponding calcium score for

2:32

this region this patient and sure enough. You can see that wow. There's

2:35

a lot of calcium.

2:38

So this patient has a really severe disease and I mentioned some of

2:41

the early videos. We were talking about indications for coronary CT that

2:45

heavily calcified

2:46

Lesions is is where coronary CTS

2:49

accuracy really kind of falls down. This is

2:52

where coronary CT has a lot of trouble now. There is

2:55

some Hope on the horizon that these some of

2:58

the newer scanners in particular the photon counting

3:01

scanners and some of the other high-resolution type

3:04

scanners that are out there may be

3:07

able to help with this problem. But for the

3:10

majority of the current generation scanners out there, this is

3:13

not an easy problem to fix.

3:16

So, how do you deal with it? Well, what you want to do

3:19

is you want to go to your

3:21

sharp kernel reconstructions. So that's

3:24

what we see here on the right. They're always a little bit more noisy, but they're

3:27

gonna give you slightly better definition of the edges of

3:30

our calcified plaque.

3:33

And then you kind of just do your best.

3:36

If you see Lumen like you do in this case.

3:40

And it looks like it's a fairly uninterrupted column

3:43

of contrast then usually I'm gonna call that mild.

3:47

When I get down further though, and I see that it's hard

3:50

for me to separate the Lumen and the plaque.

3:53

or further Downstream right here where I

3:56

see that the diagonal comes off and then

3:59

I really have

4:02

Honestly, I I can't tell if there's Lumen there or if there's calcified

4:05

plaque. It looks to me like it may be

4:08

a hundred percent calcified black.

4:10

This is where we usually give the caveat and

4:13

the caveat is heavily calcified stenosis,

4:16

you know obscures vessel

4:19

Lumen, probably 70% or greater, but maybe over

4:22

underestimated by a CT and that's sort of a standard

4:25

tagline that unfortunately we have to use sometimes

4:28

with these lesions that are really severely calcified

4:31

on coronary CT. This is the main

4:34

limitation of coronary CT in terms of accuracy when

4:37

you have tons and tons of calcified plaque. So if

4:40

we follow the vessel further, you can see we have this

4:43

big calcified lesion here.

4:45

Then we go further a little bit of narrowing

4:48

here, which looks like this probably secondary to some non-calify

4:51

black and then here we kind of lose the

4:54

vessel and that comes back again. So that makes you wonder

4:57

again if there's some non-calify black in that vessel.

5:01

Let's look at the other vessels if we look at the RCA.

5:05

Just notice here how much better with the sharp kernel

5:08

you can see the calcium then

5:11

you can on their standard kernel on the right.

5:13

That's that's why it's particularly useful.

5:16

Same thing here standard kernel, it looks kind

5:19

of like a blob of calcium here. You can actually see some definition. There's

5:22

two calcified plaques next to each other rather than

5:25

one single calcified plaque.

5:27

And then as we go down further distally in the

5:30

RCA, I think can appreciate that. There's a fair bit of calcium, but

5:33

there's no significance stenosis except

5:36

for perhaps right here at the origin

5:39

of PDA. There might be some plural narrowing.

5:42

You see that this is the plb continuation right

5:45

here.

5:47

And right there, let me see some mixed plaque

5:50

both calcium and non calcified black.

5:53

That's causing some narrowing of that PDA origin.

5:56

So we'll have to keep our eye on that on some of the

5:59

reconstructions as well.

6:01

And then to close it out. Let's take a look at the circumflex.

6:04

You can see this is a pretty dominant right corner artery. So

6:07

I don't expect a big circumflex and sure

6:10

enough. That's the case. You can see it's quite a small vessel here.

6:14

Comes down. There's an obtuse marginal Branch there from

6:17

the high circumflex and then kind of comes over.

6:20

Here and just kind of Peters out into the sort of

6:23

lateral aspect of the LV wall.

6:25

Okay, so let's take a look at the LED.

6:28

here's our CPR reconstruction and

6:32

Unfortunately, this is an example of a CPR

6:35

that doesn't always go exactly where

6:38

you need it to go. And in this case, it didn't quite follow the LED beyond

6:41

the mid segment here.

6:44

It looks like it picked up a vein and then stopped so we

6:47

can work with that because we know how to use our nprs and I

6:50

mentioned that as one of the reasons that's really important to be familiar with

6:54

how to use the nprs in these cases. So again, we can

6:57

see what looks like mild disease proximally and then when we

7:00

get past this diagonal Branch, it looks to me like there's

7:03

stenosis in the diagonal itself as well as

7:06

some calcified black and non-calify black and led beyond the

7:09

diagonal. It looks concerning for significant stenosis.

7:12

But again right here, I'd have to say that there's severe calcification

7:15

in a small vessel that obscures Lumen

7:18

visualization and suggest

7:22

70% or greater stenosis, but maybe over underestimated by

7:25

coronary CT do the heavy calcified

7:28

plaque burden that's sort of the usual phrasing that

7:31

we use.

7:33

Now one of the thing that we wanted to remember to keep

7:36

an eye on was the left mean and so here is the

7:39

left main here.

7:40

And again, it doesn't look good. It

7:43

looks like there's a severe stenosis most likely

7:46

From noncosified Plaque.

7:48

whenever you're using CPR though, you always have to be a little

7:51

bit careful because sometimes

7:53

the CPR itself can be a little bit off

7:56

center line and that can give you a fake out. So let's

7:59

check out. Let's take a look at some other views.

8:02

Circumflex, this seems to be a pretty good Center Line

8:05

and it still shows that same stenosis or

8:08

a suspected stenosis in the left main. So

8:11

I think this is going to end up being real and then

8:14

if we go to our short axis reconstructions,

8:17

That sort of a little closer to kind of

8:20

the ground truth. I think and sure enough you

8:23

can see this stenosis. So this patient has what looks like

8:26

a severe left means stenosis. That's a big deal that puts

8:29

her into the catarans for bee category and that type

8:32

of patient may need to get a cabbage to

8:35

deal with this severe disease.

8:38

We can also on this short axis reconstruction take a

8:41

look at the Led disease. So proximately here it

8:44

looks kind of mild but then when we get Beyond this diagonal Branch,

8:47

that's where we get into trouble.

8:49

Small vessel big calcification it's kind of

8:52

tough for us to tell exactly what's going on there. But I

8:55

would generally read that is suspected, you know,

8:58

significant stenosis may be overestimated or underestimated

9:01

because of the heavy calcification.

9:04

So for this patient, thankfully we have a calf follow-up

9:07

which will take a look at next.

9:10

So here's the calf in this patient.

9:13

And first I want to focus on the left mean disease. So here's

9:16

an Arrow showing us this stenosis in the left main that we

9:19

saw on both. Our curve planner reconstruction images are

9:22

short axis images and the axial images.

9:25

And sure enough.

9:27

There's a high grade stenosis of the left mean in

9:30

this patient. So this is this is a big deal.

9:33

And this is something that would need to be treated in

9:36

general with with cabbage.

9:38

Now what about that led and the diagonal

9:41

branches? Well when you look at the calf.

9:44

at the Led in the diagonal

9:46

here's the best view I could find from their cath images.

9:50

You can see the diagonal here actually looks okay surprisingly which

9:53

for us it didn't look that great. So

9:56

that's probably a function of our calcium faking us

9:59

out and then here in the LED though. We do see that

10:02

there's they did call serial stenosis in the

10:05

mid LED after the diagonal branch is how they phrased it.

10:08

And they said 80% or greater. As you can see that there's a sort

10:11

of a fuzzy stenosis here right after the diagonal origin and

10:14

then a fuzzy stenosis here and my best

10:17

guess is that these correspond to these highly calcified areas of

10:20

plaque in the mid LED beyond that diagonal that again,

10:23

we're tough for us to evaluate but looks like they did correspond to

10:26

some severe lesions.