0:00

So let's take a moment to double click on CAD rads.

0:03

As I showed you before, you have the cadrad grading

0:06

and it's actually zero through five, so zero being normal.

0:09

Uh, no plaque, no stenosis,

0:11

and uh, four being a severe stenosis, we do distinguish

0:15

CAD rads A from B

0:16

and any number of stenosis

0:18

that involve less than three vessels

0:20

and don't involve the left main as a cadrad four A.

0:24

If it involves the left main with at least 50% narrowing

0:27

or involves all three vessel territories,

0:30

it's CADRAD four B.

0:31

Why do we do that? Well,

0:32

because we know that all data available to this day shows

0:36

that there are better long-term outcomes

0:38

with bypass surgery over stenting when you have left

0:40

main or three vessel disease.

0:42

Part of the reason left main is such is

0:44

that if a stent goes down, you lose all the flow

0:46

to the left heart, which is usually a larger amount of flow.

0:48

And so, um, that can lead to death.

0:50

The other thing is the procedure is,

0:52

is a little bit more difficult and is is done, but rarely.

0:55

Another important concept to remember here is

0:59

that they can be used in combination.

1:01

So you can have cadrad four

1:03

as meaning there's a severe stenosis

1:06

and a stent in your cadrad, so use your modifiers.

1:09

And cadrad is generally based on atherosclerotic narrowing.

1:12

So if you have a coronary dissection

1:15

or an embolus, use the slash e to denote

1:18

that there is a cause of narrowing,

1:19

but it's not atherosclerosis.

1:21

The treatments may vary. In fact, some

1:22

of them there may be just conservative management

1:24

and not, uh, further therapy.

1:26

And it also might help the interventionalist realize

1:29

that there's a higher risk coronary

1:31

dissection being the obvious example.

1:32

So the risk of creating a worse dissection by looking

1:36

with an angiogram is much higher.

1:38

Another, uh, important uh, thing

1:40

to note is n So if you have a non evaluable scan so

1:43

that they're not beautiful scans like this, say that

1:46

because it means your accuracy is lower.

1:48

We've talked a bit about CAD red's five, which is occlusion.

1:51

So, uh, that's when you clearly

1:52

assure there's an occlusive disease.

1:54

And occasionally I'm not

1:55

as sure if it's a really short segment occlusion

1:57

or potential occlusion.

1:59

And here's an example of a CAD red's end.

2:00

So this is somebody with some artifact

2:02

and it looks like a stenosis, but it was negative.

2:05

Um, I'm also just showing you, uh,

2:06

what we'll see in the case examples.

2:08

A lot of too looking at even at a few milliseconds,

2:11

different phase can clear up motion.

2:13

So here's RCA motion we know that moves the most,

2:15

and you can see here, um,

2:17

a few milliseconds into the motion, um, frames.

2:20

It's non invaluable. And then at the end,

2:22

systole it's very valuable.

2:23

So, um, if you don't have those frames

2:25

and you can't freeze the motion, you have

2:26

to call it non invaluable, meaning it's a non-diagnostic

2:29

study, or at least non-diagnostic in that segment.

2:31

Here's another example of a stent.

2:33

Here's an example of a cabbage, uh, just to say

2:36

what you would use the the s and the G modifiers.

2:39

That's an aortic coronary bypass graft to the RCA.

2:41

And there's an a, a severely stenotic stent.

2:44

And the, the old, uh, CAD reds used V for vulnerability.

2:48

I think it's called HRP now, but it's high risk plaque.

2:50

So positive remodeling, spotty calcification.

2:53

Um, again, that doesn't have anything to do with the degree

2:55

of stenosis, but rather the markers of risk.

2:57

Those are long-term things

2:59

And a lot of your high-risk CAD patients will have it.

3:01

The most important thing is to get the patient

3:03

to maximal medical therapy.

3:05

You can find the CAD red's, uh,

3:07

criteria freely on the the SCCT website, the Society

3:10

of Cardiovascular Computed Tomography.

3:12

Um, just go to the website

3:14

and there's a publication section, all the guidelines

3:16

of freely available, and this is Cadre's 2.0.

3:19

So it's been updated, it's backward compatible

3:21

so you don't have to relabel all your old cases.

3:24

We, uh, tend to use this as a header for the scan.

3:28

You should still do the, um,

3:30

in your impression that's your header.

3:31

So cadre's four A, but then say where the SSIS is.

3:34

So ca red's four a colon.

3:36

There is a severe LAD stenosis

3:38

or serial severe lesions in the RCA.

3:40

We'll go through this in a lot of the cases,

3:42

but it's important to use it as a categorization system.

3:45

And it's a nice heuristic

3:46

to say quickly what's the overall coronary status,

3:49

but you don't wanna make that the only part of the report.

3:51

Another important thing that gets misused in, um,

3:54

CAD rads is it's a summary of your worst stenosis.

3:58

So you can't have CAD RADS two and three.

4:01

So if you have a mild stenosis

4:02

and a moderate stenosis, the case gets tagged

4:05

as CAD rads three, meaning intermediate as your worst.

4:08

So there's nothing worse than intermediate stenosis,

4:10

but there's only one grade for the entire patient.

4:14

And this is just one more guideline that's a little older,

4:17

uh, but it's fundamental.

4:18

This is actually first published in the

4:20

19, I think seventies.

4:22

Uh, but we've adapted it for ct.

4:24

So when you talk about coronary anatomy, it's good

4:26

to use segmental anatomy.

4:28

People tend not to report a scan

4:30

and say Segment five has a stenosis.

4:32

But it is important to note that the left main stops

4:36

where the coronary bifurcate or trifurcate

4:39

or that the proximal LED um, begins after the left main

4:43

and ends at the first large septal, perforator

4:46

or diagonal, whichever comes first.

4:48

Uh, it's important to denote whether someone has a right PDA

4:51

or a left PDA and so on and so forth.

4:53

So when in doubt, just consult these again,

4:55

freely available on the SSCD website.

4:57

And this is well published for decades,

4:59

but important to speak the language

5:01

of cardiology when talking to a cardiologist

5:04

or a cardiac surgeon.