0:00

Alright, next case is a 58-year-old patient

0:03

and we know they have a stent.

0:05

So they have known coronary disease that's been treated.

0:08

Interestingly, a few months before this test, uh,

0:11

they underwent a stress echo

0:13

and it just showed a mild inter apical wall motion under

0:15

Maori, an apical would be LED territory,

0:18

and that's where the stent is.

0:19

We do acquire a non-con scan on these, by the way.

0:22

Uh, we don't obviously interpret a calcium score

0:25

because it's irrelevant,

0:26

and then it would give you a high number

0:27

because you're measuring metal.

0:29

Um, and there's no need to measure pretest risk.

0:31

You know, it's definite risk.

0:33

Uh, I still like the non-con

0:34

because you're gonna see these spots

0:35

of calcium you might miss

0:36

and that might help you sort something out.

0:39

Um, the other thing that I find a non-con calcium score, uh,

0:42

acquisition, good for on stents is if there's fractures.

0:44

So it's really easy to spot. Um, so we always do it.

0:48

It's a minimal radiation expense,

0:49

but it's a sometimes beneficial.

0:52

Um, I will go right to the CTA, just knowing

0:55

that it's good quality.

0:56

RCA looks fine. Let's show the, uh, left main.

0:59

There is some plaque in this left main

1:01

and, uh, left main's always

1:03

warrant a little bit of extra attention.

1:05

Um, but I just wanted to show

1:07

and highlight that you can see the plaque along the superior

1:10

wall of the, uh, left main here.

1:12

So coming off the aortic root,

1:13

but, um, plaque is hard to distinguish from epicardial fat.

1:17

I can see the difference here.

1:19

Uh, but there's a epicardial fat there. This is air density.

1:22

Um, but there is a distinguishing signature density.

1:26

Uh, Tom sometimes takes a little care to figure that out.

1:28

So we know there's plaque but not stenosis in the left main.

1:31

And, uh, let's look at that stent.

1:33

And, um, this is a great look at a stent.

1:36

The technology only gets better.

1:37

Uh, but this is a, just a standard protocol.

1:40

We add a sharp kernel to every CT we, um, create

1:44

and we, uh, find that to be useful

1:46

for reducing calcium blooming and stent blooming.

1:49

Um, second teaching point is,

1:51

and we talked about this in the lecture, uh,

1:54

we see contrast in the native vessel before the stent.

1:57

The stent itself has maybe a millimeter

1:59

before it becomes occluded.

2:00

And by the way, a, a tiny trickle

2:02

of flow in there could certainly be possible.

2:04

It's hard to say you get some artifact within it,

2:06

so it's difficult to be very accurate.

2:08

Um, but when we go beyond the stent, it's important to note

2:12

to the team that there is some atherosclerosis slash

2:16

occlusion beyond the stented segment

2:19

and into the native distal segment.

2:21

Uh, and that matters because that's new disease

2:24

or disease that wasn't treated

2:25

and perhaps that's why the stent went down.

2:27

And second point is you can see denser contrast here,

2:31

less dense contrast here.

2:32

This is probably retrograde flow.

2:34

Um, there's more than likely ample collaterals from either

2:38

left to left, left to right,

2:40

transseptal, uh, all kinds of ways.

2:42

Um, but the CT won't depict that.

2:45

That'll show that you got some contrast on

2:47

the other side of the stent.

2:49

Um, but if there's ever a, um,

2:51

clear cut case, it's this one.

2:53

If you can't see in the stent, you can say that

2:54

and just interpret everything else

2:55

and just be very careful

2:56

to say it's a non invaluable stent. In

2:58

This this case, I can evaluate the stent.

3:00

So I'm gonna give it a CAD RADS five for occlusion.

3:03

If it's subtotal occlusion, I'll be okay with that.

3:06

It's going to be a slash s for stent.

3:09

And I'm gonna note that I see a little bit of disease

3:13

beyond the stent in the native LAD

3:16

and I really don't see anything else.

3:18

I just see some left main plaque.

3:20

In fact, that left main plaque is humbling

3:22

because that is noncalcified plaque.

3:24

You saw that the calcium score was negative.

3:25

So any test other than a CT angiogram is gonna miss that.

3:29

So it's certainly already gonna be maximum medical

3:31

therapy, uh, for this extent.

3:33

The thing is, he, he is getting symptoms.

3:34

There's an abnormality of profusion, um, by the stress echo.

3:38

I'm not gonna show you that 'cause it's a cumbersome process

3:41

to look at a stress echo.

3:42

Um, you're looking at wall motion

3:44

and the changes in wall motion.

3:45

But I just wanted to look at the myocardium here on the CTA

3:50

and I'm, this is the, the coronary phase.

3:52

One other way to look at the myocardium is

3:55

to thicken up your slices.

3:56

So, um, a couple of sites, including ours,

3:59

have done some studies on what's the best, uh, way

4:02

to look at myocardium with CT turns out to be, in my opinion

4:06

and my paper, uh,

4:07

eight millimeter thick multiplanar reformat

4:09

tight window width level.

4:10

Um, some vendors do allow you to do color mapping

4:13

and fancy things, but you're just looking

4:15

for relative hypo enhancement.

4:17

Uh, the other thing you can look at on the ischemic cascade

4:19

as we talked about, was looking for wall motion.

4:22

So here I'm in the short axis and I've got a two chamber

4:24

and a pseudo four chamber.

4:26

I can even turn it into a true four chamber

4:27

by just bisecting the acute margin of the right ventricle.

4:31

Um, but I'm most curious about this area here.

4:34

So I'm gonna give you an, uh, three chamber view.

4:37

So I'm gonna go up to that, uh, basal slice bisect,

4:40

the LVOT, and then I'm going to animate this for you.

4:43

So, um, short axis here.

4:45

So the stress echo showed intra septal down by the apex.

4:50

I'll read that for you. Mild inter

4:52

apical wall motion abnormalities.

4:54

So, um, we're in the mid segment here

4:56

and there's the apical a little noisy,

4:58

but I I could say that there's maybe some hypokinesis.

5:00

Let's look on the three chamber.

5:02

Um, it does not thicken as much.

5:04

It's a little thinner and it doesn't fully thicken.

5:06

So I think I'll agree with the stress echo.

5:09

Um, oh, that's actually a nice view there. By the way.

5:12

This is noisy, but it's enough, um,

5:14

perhaps less noisy than some of the nuclear scans we see.

5:17

So let's move on. Now, can't send this one for, uh,

5:20

C-T-F-F-R because it's not the time of this recording.

5:23

There's no FD approval for C-T-F-F-R in stented patients,

5:27

um, by the vendor that our hospital uses.

5:30

Uh, looks like the next test done

5:33

was an FDG PET ct.

5:36

That test showed a large size, moderate severity mid

5:40

to distal anterior wall and apical ischemia.

5:42

So reversible perfusion, beautiful

5:44

because that's exactly where the territory

5:46

of the LI stent would be and where the echo, uh, segments.

5:51

So we're all speaking the same language.

5:52

The target meets the vessel.

5:54

So a good next step would be to go onto an

5:57

Invasive coronary angiogram.

6:00

Okay, so here we are

6:01

with the catheterization on this patient.

6:03

So in summary, we had a CT showing occlusion.

6:05

There might've been a trickle,

6:06

but we, we called it subtotal total occlusion.

6:09

Uh, and gave it a cataract five

6:10

'cause it looked like the disease went beyond the stent.

6:12

We got a nuclear test, which confirmed ischemia in

6:16

that territory and corroborated the echo

6:18

and the CT findings of wall motion abnormality.

6:21

And here you have this really tight stenosis,

6:24

but there's a nice example

6:25

where the superior spatial resolution

6:28

of an invasive angiogram shows

6:29

that there's a little trickle of flow there.

6:31

So the right things happen that the stent was identified

6:34

and treated before it, we lost the vessel.

6:37

Uh, that trickle of flow still could have retrograde

6:39

or just slower flow beyond it.

6:40

Um, but the dynamic information

6:42

that a cath has is complimentary and in this case, superior.

6:46

So, um, the nice thing when you have a stenosis like this,

6:49

you're able to wire it quickly

6:51

'cause you have to get a wire, um, across that lesion.

6:54

Just like we talked about with chronic occlusions.

6:57

It's a little harder to, to cannulate those.

6:59

So that makes a nice, um, roadmap

7:01

and highway for your, your stenting procedure.

7:04

And let's see what the final result is.

7:07

I'm glossing through a lot of cath.

7:08

These are a lot of work, but beautiful result here.

7:11

So, um, successful stenting, uh,

7:13

or re stenting of the vessel.

7:16

Uh, and again, a lot of additive information from the CTA in

7:20

that there was native disease not treated beyond the vessel.

7:22

So that's a, uh, a known reason for, uh, stent failure.

7:26

In fact, new guidelines recommend that when

7:28

of stent is placed and intravascular ultrasound is performed

7:31

to make sure they don't miss disease.

7:33

Uh, because then progression is obviously gonna happen in

7:36

the non-treated segment.

7:38

So, in summary, a great case of CTA sensitivity,

7:41

maybe some complimentary role of profusion

7:43

and, and wall motion imaging.

7:45

And then, uh, catheter angiograms, superior

7:48

spatial resolution.