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This was an individual who was trimming trees

0:03

and fell from his truck onto the asphalt.

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This is the initial CT scan from the patient's study.

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And the initial run through

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suggests that the patient has had an injury in

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the scalp at the high left frontal region.

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We're going to look at the calvarium in just a moment,

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but the next thing one sees in a flash going by is some

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hyperdensity along the top of the corpus callosum,

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and maybe a little bit of blood that's collecting

0:48

in the lateral ventricles.

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If we look at the patient's calvarium,

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see that there are no fractures.

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Coronal scans would be helpful to look in the gyrus

1:07

rectus region for hemorrhage or contusion,

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as well as the anterior temporal lobes.

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And we wonder about a collection here along the floor

1:18

of the middle cranial fossa on the left side.

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We see some of that blood products adjacent

1:25

to the lateral ventricles.

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The patient was not doing well and got scanned

1:32

6 hours later as part of the protocol.

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Here on the six-hour scan,

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we start to see a little bit more density than

1:43

we're comfortable with along the tentorium,

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suggesting that there may be a subdural

1:47

hematoma layering along the tentorium.

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And now we see more clearly intraventricular hemorrhage

1:56

in the occipital horns of the lateral ventricle.

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As you recall,

2:00

this is usually a marker for an

2:03

injury to the corpus callosum,

2:06

usually the posterior body and/or the splenium.

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A little bit of blood products also seen near

2:14

the foramen of Monro on the left side.

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Since the patient was doing very poorly and

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yet the imaging was relatively mild,

2:26

the patient was referred for MRI scanning.

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The MRI scan,

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if we look at the initial FLAIR image,

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you'll note that the normal

2:37

low signal intensity of the subarachnoid

2:40

space that should be present on a FLAIR scan,

2:45

as you can see in the cerebral spine fluid of the ventricles,

2:50

is lost over the high convexities.

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This bright signal on FLAIR scan is an indicator

2:56

for subarachnoid hemorrhage.

2:58

Now, this may be anything of pathology

3:01

in the subarachnoid space,

3:02

so it can be meningitis in a different situation.

3:05

So there's subarachnoid hemorrhage

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and we see that, indeed,

3:09

there is injury to the splenium of the corpus callosum

3:13

and there is blood that is seen within the occipital horns

3:18

of the lateral ventricles on the examination.

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The next thing, as we go downward,

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we start to see is abnormal signal intensity in the

3:28

back of the brainstem at the tentorial edge.

3:32

Remember that I said that an acceleration-deceleration

3:35

injury site of pathology includes the posterior midbrain

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as the brain goes forward and back and the midbrain bangs

3:47

up against the hard dural margin of the tentorium.

3:51

This is what you are seeing here in the midbrain,

3:57

more on the left than the right,

3:59

on this FLAIR scan.

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You'll note that even in the posterior fossa,

4:05

the vermian subarachnoid space is bright

4:08

on FLAIR scan, which is abnormal.

4:13

We then move from this to our diffusion-weighted scan.

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Why do we look at the diffusion-weighted scan?

4:19

Diffusion-weighted scans are useful in identifying some of

4:24

the shearing injuries that can occur in trauma

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because they do induce cytotoxic edema.

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And indeed, in the splenium of the corpus callosum,

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we see bright signal intensity on the DWI scan,

4:39

likely from a shearing injury.

4:42

Shearing injury, diffuse axonal injury,

4:45

rotational deceleration injuries are all part of the same

4:50

spectrum and are used relatively interchangeably.

4:53

The most important sequence, however,

4:55

that we want to look at is the gradient echo or

5:00

susceptibility-weighted scan.

5:02

In this case, a gradient echo scan

5:04

was performed on this 1.5 Tesla scanner

5:08

that did not have SWI pulse sequences.

5:11

Nonetheless, even using gradient echo scan,

5:14

we can see that there are multiple dark signal-intensity foci

5:18

at the gray-white interface,

5:21

characteristic of shearing injuries of the white matter.

5:26

You see that they are these little black dots that

5:30

are bilateral in this individual.

5:32

Not only that,

5:33

but as we get to the splenium of the corpus callosum,

5:36

we see that indeed there is hemorrhage in the splenium of

5:40

the corpus callosum and along the posterior septum

5:43

pellucidum extending to the edge of the splenium.

5:47

You'll also see intraventricular hemorrhage

5:50

on the gradient echo scan.

5:52

As we go further inferiorly,

5:55

we do see some of the blood products in the back

5:57

of the brainstem. So these little black dots

6:00

represent hemorrhage in the back of

6:02

the brainstem, in the midbrain,

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where the midbrain has opposed against the edge

6:09

of the tentorium. And here in the vermis,

6:13

you also see blood products

6:15

demarcated by the dark signal intensity.

6:19

So, this is another example of a

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patient who did not do well

6:25

and was subsequently shown to

6:27

have a much more extensive

6:29

degree of injury from diffuse axonal injury

6:32

demonstrated on the MRI scan.

6:35

There's one more scan that was performed

6:38

four days after the MRI scan.

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And as you can see,

6:43

the CT just will totally underestimate the degree of

6:47

damage that has occurred.

6:49

You had the CT scan beforehand,

6:51

you had the CT scan after,

6:53

and they just look relatively mild injury

6:57

when we know that there has been a devastating

7:00

injury at the gray-white junction.

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This patient has, what one typically sees,

7:07

is a pressure bolt to monitor the intracranial pressure

7:11

as part of the therapy for the patient.