0:01

So this is a typical case of a

0:03

patient who presented with aphasia.

0:05

When we consider aphasia, we're always concerned about

0:08

a left middle cerebral artery distribution infarction,

0:12

and that's because most right-handed people have

0:15

language largely on the left side of the brain.

0:20

So that might be different in a left-handed

0:22

individual, in which case it may either be

0:25

balanced, or it may be on the right side of the brain.

0:28

Um, so anyway, as we would normally do, I

0:32

would start with looking at the thick-section

0:35

images, basically to look for hemorrhage.

0:39

One of the most important things that we're going to

0:41

be doing in patients who we're considering stroke is

0:44

to look for hemorrhage, because that would prevent

0:49

the patient from being considered for thrombolytic

0:53

therapy, or in most cases, for thrombectomy.

0:56

So the presence of hemorrhage

0:58

is the most important thing.

0:59

And so we're gonna look on the thick-section images.

1:02

So this is the axial scan through this patient.

1:04

And as we look at the patient's study, we notice

1:07

that there are areas of low density in the patient's

1:10

brain, both in the putamen region on the left

1:14

side, as well as in the left frontal region.

1:17

Looks like the patient has had a prior craniotomy, but

1:20

what I'm not seeing is any evidence of hemorrhage.

1:23

So this patient, a priori, may be a candidate

1:28

for getting IV tPA, the tissue plasminogen

1:33

activator factor, or potentially thrombectomy.

1:37

The next thing we want to do, so we want to see

1:40

whether there's any mass effect, because if the

1:42

patient is herniating, obviously that's another

1:45

emergency, in which case the patient may need

1:48

either a craniectomy to reduce the mass effect

1:52

or even potentially steroids.

1:54

So as we look at these thick section

1:56

images, we are not seeing mass effect,

1:59

midline shift, or herniation of structures.

2:03

The next thing we want to do is try to

2:05

see if we can identify the thrombus, because if we can

2:08

identify the thrombus itself and where it's located,

2:12

it will be helpful to the interventionalists

2:15

for deciding whether or not to go after it.

2:17

Obviously, if it's far peripheral

2:20

in the vasculature, it's much harder to find and get to,

2:24

whereas those lesions that are proximal in the

2:28

internal carotid artery or in the M1 segment of the

2:31

middle cerebral artery have a better success rate.

2:35

So for that, I would switch to the thin section images.

2:38

So these are the thick section images that are

2:40

approximately five millimeters thick, as you can

2:44

tell.

2:45

And now what I'm going to look

2:46

at are the thin section images.

2:48

This is 351 images.

2:51

The previous dataset was 36 images.

2:54

So as I scroll through these images, I'm

2:57

going to be very cognizant of the density

3:01

of the internal carotid artery bilaterally,

3:05

as well as the middle cerebral arteries.

3:08

Now, what you'll see is that there's going

3:10

to be some calcification of atherosclerosis.

3:13

That typically occurs in the cavernous internal

3:16

carotid arteries, which is what we are seeing

3:18

on either side—the right and the left

3:21

internal carotid artery in the cavernous sinus.

3:24

But as we continue further superiorly, what we notice

3:29

is this hyperdense area in the expected location of

3:33

the M1 segment of the middle cerebral artery. This is in

3:37

a location that is definitely amenable to thrombectomy,

3:41

and although the patient does have prior strokes,

3:44

those low-density areas—we might be able to save a

3:49

large area of the middle cerebral artery distribution

3:52

by virtue of removing that thrombus in a timely fashion.

3:57

So, at this juncture, I've identified a dense MCA.

4:02

I've seen older areas of encephalomalacia, likely from a

4:07

craniotomy, as well as an infarction in the left putamen.

4:12

That's old.

4:13

Why do I say old?

4:14

Because it's low density.

4:16

Acute infarctions would not be low density,

4:19

and I'm not seeing any other findings

4:23

that would suggest an acute infarction.

4:26

So, from this point, in most situations, the

4:30

patient would go on to a CT angiogram to identify

4:34

the thrombus, to identify the anatomy that

4:37

would be necessary for the interventionalist to

4:42

have available in navigating to that thrombus,

4:46

and, as well, to look for any other additional

4:49

findings, including occlusions in other

4:52

blood vessels or the incidental aneurysm

4:55

that may need to be treated along the way.