0:00

This was a passenger,

0:02

an eleven-year-old passenger in a motor vehicle collision.

0:07

The CT scan

0:10

shows a relatively small collection

0:14

over the left parietal region

0:19

that has a lentiform shape to it,

0:23

and there is associated some subarachnoid hemorrhage,

0:28

but it looks like a relatively small area of injury.

0:34

We want to look at the bone windows to see

0:37

whether there is a fracture.

0:39

And indeed,

0:40

one can see that the inner table of the calvarium

0:45

is fractured in this individual.

0:47

So this was the coup side of the injury.

0:52

And the patient has a small epidural

0:55

collection associated with it,

0:57

likely from a small tear of a middle

0:59

meningeal peripheral branch.

1:01

Just to be sure,

1:02

we would look at the thin-section images.

1:05

These are the 1 mm thick sections.

1:07

The disadvantage of looking at the thin-section images is

1:11

that they do get more noisy

1:13

since it is a 1 mm thick section.

1:16

Nonetheless,

1:18

although we can see some of the subarachnoid hemorrhage,

1:20

we are still seeing a relatively small

1:23

extra-axial collection here.

1:25

We can measure this and 5 millimeter

1:30

extra-axial collection,

1:32

likely an epidural hematoma from a peripheral

1:35

middle meningeal injury from the fracture.

1:38

So call into the clinicians and say,

1:42

I see a minor injury with a small incomplete fracture,

1:46

small epidural hematoma measuring 5 mm by 2 cm by 1cm,

1:53

a little bit of subarachnoid hemorrhage.

1:55

And they respond to you,

1:56

"Oh, the patient's doing really well."

1:58

The patient is doing very poorly and

2:02

has alteration of consciousness.

2:07

So, the patient will likely get serial scanning.

2:11

And you're kind of unimpressed with the degree of

2:16

the pathology, even on the thin-section images.

2:19

At this juncture,

2:21

if there is a discordance between the neurologic

2:25

examination and the CT scan,

2:28

generally, the clinicians will repeat the

2:32

scanning at the six-hour mark with CT.

2:35

However,

2:36

particularly in children where they don't want to do

2:38

serial CT scanning,

2:40

they may proceed to get an MRI scan.

2:43

Let's see what happens to this individual.

2:46

Okay.

2:47

So, this is the same patient with the six-hour scan.

2:53

And as we look at the patient study,

2:56

we see that this epidural hematoma has increased in size,

3:02

and there continues to be subarachnoid hemorrhage.

3:06

Remember to look contrecoup.

3:09

So, we saw that there was a fracture in the left parietal

3:13

region and the epidural hematoma.

3:15

As we look contrecoup,

3:17

we're not seeing very much in the right hemisphere.

3:24

And the clinician say the patient's doing very poorly.

3:28

So, they may scan again at 6 hours

3:32

or depending upon the width of this collection,

3:35

they may intervene.

3:36

Let's measure it.

3:40

Epidural hematoma,

3:42

measuring 2.2 cm.

3:46

That's an indication for surgery.

3:47

As you recall,

3:48

the epidural hematoma

3:50

indication was 15 mm width

3:54

or 30 CCs of volume.

4:00

In this case, they decided to wait

4:03

and the next scan we get is an MRI scan.

4:07

On the MRI scan,

4:09

I'm going to show you the FLAIR scan first.

4:12

So, this is a FLAIR scan.

4:15

Dark CSF,

4:19

dark white matter,

4:22

higher-intensity gray matter.

4:25

And you can see the collection of blood,

4:29

as well as what looks like an underlying

4:33

hematoma in the brain or contusion

4:38

and likely the subarachnoid hemorrhage.

4:40

There really isn't much in the way of midline shift.

4:44

You probably want to look at the

4:46

T1-weighted scan, as well.

4:50

And it shows the mixed signal intensity blood products.

4:54

And this is both dark on T1 as well

4:59

as areas of high signal on T1.

5:01

And by virtue of the fact it was dark on T2,

5:04

we know that this is deoxyhemoglobin.

5:08

You see that there are some blood products in the

5:10

subarachnoid space, as well.

5:12

Other than that, not too bad.

5:17

If we look at the diffusion-weighted scans,

5:20

we just see a little bit of cytotoxic

5:22

edema in the area of the hematoma.

5:30

We have a T2-weighted scan, as well.

5:33

Again, dark signal intensity on T2-weighted scan,

5:36

lentiform shape,

5:37

likely representing acute epidural hematoma.

5:40

Parenchymal hematoma with edema.

5:44

Otherwise, looking pretty good.

5:48

So, you dictate epidural hematoma with

5:52

mild contusion in the posterior,

5:58

left frontal, lobe and parietal lobe,

6:00

with associated subarachnoid hemorrhage,

6:03

22 mm in thickness, no midline shift.

6:09

What did you forget to do?

6:13

Well, I've told you before

6:16

that the best sequence for detection

6:20

of blood is susceptibility-weighted scan.

6:23

This is the SWI scan,

6:26

the susceptibility-weighted scan of the exact same patient.

6:30

You'll note the very dark signal of the extra-axial collection.

6:34

However, in addition, look for black dots.

6:40

Here are black dots of deoxyhemoglobin in the subcortical

6:44

white matter in the area adjacent to that contusion.

6:49

But you can see that these little black

6:52

dots are really all over the place.

6:55

Here at the gray-white junction.

6:58

Here in the right frontal lobe.

6:59

These black dots are not veins.

7:02

How do we know that they're not veins?

7:03

These are the veins here.

7:05

The veins usually are branching and they usually

7:07

go from smaller to larger as they go centrally.

7:11

Here's a hemorrhage in the splenium

7:14

of the corpus callosum.

7:19

Here is hemorrhage

7:22

in the subcortical white matter of the parietal lobe,

7:29

as well as

7:31

the more posterior parietal lobe.

7:34

And as we look further inferiorly,

7:37

look at the frontal lobes.

7:39

Lots and lots of these black dots all over the place.

7:43

This is our gyrus rectus region.

7:45

And there's blood products along the posterior gyrus rectus.

7:48

Here we have the temporal region on the left side.

7:52

Look at right along the gray-white matter interface.

7:58

All of these areas of dark dots.

8:01

These are all areas of shearing injury, hemorrhagic,

8:05

shearing injury from diffuse axonal injury,

8:09

in a rotational acceleration deceleration injury.

8:12

There's even hemorrhage in the cerebellum.

8:15

None of this is apparent on the T2-weighted scan,

8:19

nor on the FLAIR scan,

8:21

nor for that matter,

8:23

on the accompanying CT scan from the same day.

8:27

This is the power of MRI, in particular

8:32

with susceptibility-weighted scanning.

8:34

In a patient who has discordance between the imaging

8:38

findings on CT and the neurologic deficits,

8:42

one should definitely recommend susceptibility-weighted

8:46

MRI scan in the setting of potential

8:49

diffuse axonal injury.