0:01

Next case is a common use of CT in some settings.

0:05

Uh, and this is an emergency chest pain patient.

0:08

And what you have is, um, somebody that had a

0:13

stressful situation created substernal chest pain

0:17

and they had the high sensitivity troponin

0:20

that most hospitals are using now.

0:22

And it was elevated but low. So it was the values we use.

0:26

Um, it came out 26

0:28

and 22, so it was positive trended downward,

0:30

but really you're not clearly an MI until you're

0:33

around a hundred and beyond.

0:34

So this is, uh, something you have to explain.

0:38

And there is a differential myocarditis,

0:41

the pulmonary embolism all, in fact,

0:43

this person had a PE rule out

0:44

and they didn't find one, so they proceeded further.

0:46

So, um, well coronary artery atherosclerosis

0:51

confirmed by the calcium score very high.

0:53

In fact, let's just say what this is. 1,876.

0:57

Um, we never stopped there. Uh, I'm gonna look at that rca.

1:00

And already I'm pretty, uh, concerned, uh, about potential

1:05

for somewhat proximal disease.

1:07

Let's turn this on its axis

1:09

and nothing severe.

1:14

My guess is this is at worst, moderate,

1:16

and maybe even just mild

1:17

'cause it's very densely calcified this distal RCA though

1:20

little harder for me to say.

1:23

Anything smart about that. Let's just double click on that

1:25

and look at another view.

1:27

Yeah, and these smaller the vessel, the more

1:30

inaccurate you're gonna be

1:31

because you, you're, it's harder to see the findings

1:33

and there's more motion and noise.

1:34

So at least moderate distal RCA and probably mild proximal.

1:39

Now we're gonna move on and look at the left main

1:41

and commandment.

1:42

Number one, thou shalt not miss left main disease.

1:45

There is a, um, very short left main here

1:48

and you can see it immediately bifurcates,

1:51

and I don't think I would call it severe.

1:55

Sometimes when I'm worried about a left main though, uh,

1:58

I like to do an area measurement that tends

2:01

to correlate pretty well with intravascular ultrasound, uh,

2:04

which is a way an interventionalist can use

2:06

to decide if something's significant

2:09

in this case, why not?

2:12

Let's do a, uh, so you just make a little ROI.

2:16

So this area is 7.1.

2:18

I might be a little bit liberal on my, uh, drawing there,

2:21

but the, I'd probably be even higher.

2:23

4.5 millimeters

2:24

and lower millimeter squared is, uh, tends to correlate

2:27

with the positive cases.

2:29

Some studies have shown seven,

2:31

but this is gonna be beyond seven,

2:33

so I think it's probably not left main disease.

2:35

There's irregularity. It'll, it'll be disease

2:37

but not severe disease and significant disease.

2:39

But when I look at this LED, I see tons of calcium.

2:42

I know there's some blooming artifact

2:44

that's gonna hamper my accuracy, but it's way too long.

2:47

And I see kind of small lumen there.

2:50

I always like to look at a couple views through it.

2:53

This is a couple of series

2:54

of at least moderates, maybe even severes.

2:57

Um, and then you can see the native distal vessel.

2:59

And even beyond all those branches,

3:01

it's still a almost three milliliter vessel.

3:03

So this is a positive till proven.

3:06

Otherwise I just happen

3:07

to land on the circumflex on this view,

3:09

but I already don't like what I'm seeing.

3:11

Just gonna MIP that for you to, to move through,

3:13

but, okay, so irregularity

3:16

and maybe a moderate due to densely calcified,

3:18

partially calcified plaque.

3:20

Um, let's just do a little bit

3:21

of a MIP in the lateral view here just to, um,

3:25

look at those oms.

3:28

Oh, okay. So, but again, there's a,

3:29

this is an OM turning into an, uh, from,

3:32

from the circumflex, but that's positive.

3:34

So series of probably moderate lesions in the OMS serial

3:38

stenosis, at least moderate, maybe severe in the LAD, uh,

3:42

and then a distal RCA.

3:44

So what happens next?

3:46

One could argue no, even if you did an FFR

3:49

or something fancy like that,

3:50

it's not gonna change management.

3:52

The next step should be what came next,

3:54

which is an invasive angiogram.

3:57

So I hope if you work at a, a hospital that does lots of,

4:00

um, ct,

4:01

but even a small amount, you should follow up your cases

4:03

and see what the catheter angiogram shows.

4:05

And we do it systematically.

4:07

So we've done it intermittently through the years.

4:08

And now we've got a program where anyone

4:10

that gets a CT gets tagged and watched.

4:12

And if they have a follow-up cath, then we like to correlate

4:15

and make sure that we are accurate.

4:17

And new readers are always honing their eyes.

4:19

So, um, this is

4:20

what you're getting in this course right now, of course.

4:22

But, um, I see some irregular, some disease there.

4:26

It's not as impressive, uh, on this view by, uh, calf,

4:30

but we know that, that the, they get less affected

4:32

by blooming artifacts.

4:34

So probably serial mild stenosis, a lot of tortuosity.

4:39

I think I was worried about an OM there.

4:41

Wow, that doesn't look nearly as bad as I thought I'd see.

4:46

I think though there is a fair amount of disease there.

4:50

Looks to me like that was, um,

4:54

bothering the interventionalists too.

4:56

They shot the RCA, okay, not the worst.

4:59

Some, some mild disease.

5:01

And they actually agreed with other,

5:05

there's enough irregularity probably worth pursuing.

5:07

And what you'll see here is they went on, um,

5:10

put some wires down, uh, and did some complex work.

5:14

And what ultimately happened was the LED, which also looked

5:19

to me like our, our worst stenosis was, uh, LED.

5:22

And the second diagonal were both stented.

5:24

You can see that in progress there.

5:26

Let's look at our angiographic result.

5:28

The, uh, IFR, which stands for again,

5:31

instantaneous freeway ratio that, uh, is um, similar

5:35

to an FFR, uh, and that it's measuring flow

5:38

and, uh, better predictor than just anatomic stenosis.

5:42

So positive confirmatory

5:44

and um, probably in the setting of

5:46

what would be considered an acute coronary syndrome

5:49

because whether

5:50

or not the troponins were leaking, it was a,

5:52

uh, acute chest pain.

5:53

We did have a mild troponin leak and, um, disease

5:56

That correlated. So

5:57

it would be unstable angina

5:59

and in this case actually an N stemi.

6:00

So a non SD elevation, MI because there was troponin leak.

6:04

So a very appropriate use for both CT

6:07

and for invasive angiography.

6:09

In fact, the most appropriate for both.

6:10

Um, we know that severe stenosis is an elective phenomenon

6:14

if there's not an acute, uh, chest pain to go with it

6:18

and a somewhat complex stent

6:19

'cause it was a bifurcation stent of this, uh,

6:21

dag in this LED, so complex disease.