0:01

Alright, let's jump right in with our first case.

0:03

And this was a trauma case.

0:05

What I like to do when I'm looking at trauma cases of the orbits is to have

0:10

the axial scan side by side with the soft tissue and the bone windows.

0:15

So that way I can sort of glance from side

0:18

to side looking initially for bone injury and then soft tissue injury.

0:22

So let's start with scrolling through

0:25

the left-hand side, which is the bone imaging.

0:29

And as I scroll through the left hand

0:31

side, I can recognize that there are no fractures on the axial scans.

0:37

I'll confirm that on the coronal reconstructions.

0:40

One of the good hints that there is

0:42

absence of a fracture is the inability or the absence of seeing an air-fluid level

0:49

in the maxillary antrum or in the ethmoid sinuses.

0:52

Usually with a fracture, you will see blood products that are hyperdense on the soft

0:57

tissue window seen in the maxillary antrum or orbital

1:03

floor fractures and in the ethmoid sinus for lamina papyracea, medial orbital

1:09

wall fractures, and those are the most common fractures to involve the orbit.

1:12

In this case, we're not seeing that and looks like the walls are intact.

1:16

Again, we will confirm that on the coronal imaging.

1:19

So then we shift our focus to the right

1:22

hand image, the right-hand image is our soft tissue image, and you notice that I am

1:26

scrolling through the images that are the 0.75 millimeter thickness.

1:32

So I believe in looking at the orbits

1:34

with the thinnest section imaging rather than the reconstructed 3 millimeter which you see

1:40

are series one and two on this particular case.

1:43

So we're looking at the 0.75 millimeter thick soft tissue windows.

1:49

And I like to start basically from the anterior and go posterior,

1:54

from the superficial and go deep. On this anterior-most portion of the orbit, you can

2:01

see that there is soft tissue thickening of the eyelid overlaying the globe itself.

2:07

And as you can compare the right side

2:11

to the left side, you'll see that there is thickening on the left side.

2:14

Now, I would tell you that 90% of the time, when you're looking at orbital trauma, you

2:18

will notice that it is the left eye that is traumatized.

2:21

And you might ask, "Well, why is that?"

2:23

Basically,

2:25

when you're facing another person and you are a right-handed person,

2:29

you punch the left eye of the person facing you, and so that's why left eyes are

2:36

much more commonly traumatized than right eyes.

2:39

For a right-handed person to swing across

2:41

and hit the other person's right eye would require him crossing the nose.

2:47

So sometimes you will see nasal bone fractures and right orbital trauma.

2:51

But for fisticuffs, for altercations,

2:54

you'll see that it's the left eye much more common than the right eye.

2:57

When we look at the orbit,

2:58

after looking at the skin surface and the soft tissue and the subcutaneous

3:02

edema, that's seen in this patient who's got a shield overlying the affected eye.

3:10

The next thing you will see is the surface

3:12

of the globe with this little bright rim around it.

3:15

And I'm going to use my little magic pen

3:17

here and point out what I'm looking at is this superficial portion where there's

3:23

a little white line that outlines the globe.

3:27

That is the cornea and the sclero,

3:30

the cornea overlying the lens and the sclero margin as you go out laterally.

3:36

I look for discontinuity in that line,

3:39

and that would imply a corneal abrasion or a laceration in the cornea.

3:45

The next area to look at is the anterior chamber of the globe.

3:50

The anterior chamber of the globe is

3:52

that portion which is just in front of the lens.

3:56

So here's our lens. And just in front of it is the anterior chamber of the globe.

4:03

And it's between those two lines.

4:06

If you see high density in the anterior

4:09

chamber of the globe, it's called an anterior hyphema.

4:13

An anterior hyphema is blood in the anterior chamber.

4:16

So let's look at this patient, and we notice that there is this irregular soft

4:23

tissue in the anterior chamber of the globe.

4:25

I'm going to switch to a different section.

4:28

So you notice that on multiple of these

4:31

examples, that anterior chamber is not as well seen as on the right side.

4:36

And that is because there are blood products in the anterior chamber.

4:41

Not only is the anterior chamber hyperdense

4:43

here, it's more shallow in depth than the contralateral right side.

4:51

So I'm going to use my pen again and point this out.

4:55

This is the anterior chamber right here, and the depth of it, as well as its

5:00

irregularity, is different than that on the right side.

5:03

That's because there has been anterior chamber rupture.

5:07

So diminution in the AP diameter

5:10

of the anterior chamber is one of the premier findings of globe rupture.

5:18

Too often when we think of globe rupture, we're looking at the vitreous.

5:22

This is the vitreous behind the lens.

5:24

In this case, the vitreous is intact,

5:27

but the anterior chamber has ruptured, and that's still a globe rupture.

5:32

Now let's look at the lens of the eye.

5:35

What you see with the lens of the eye

5:37

on the normal side is a nice elliptical appearance to the lens.

5:41

It's got nice borders and shape.

5:43

If we look at the contralateral,

5:45

the affected one, it is actually less dense and it has irregular borders to it.

5:52

Let's look at that on multiple sections.

5:55

So as we scroll,

5:57

you notice that the anterior shape of the lens is much different on the right

6:02

side and it just never has a good quality periphery to it.

6:08

And that's because it has been ruptured.

6:10

Not only has it been ruptured, but you can see that its angulation is off.

6:14

So let's look at that. Nice lens in the center.

6:18

This is our ciliary apparatus on either side.

6:22

This lens is angled this way, not in the correct orientation.

6:28

This is a patient whose lens has been dislocated.

6:32

And that irregularity and loss of density that I mentioned is a traumatic cataract.

6:42

Let me see if I can convince you

6:44

that the density of this lens on the left globe is less than that on the right

6:48

by changing the window and level until we can no longer see the left lens.

6:56

So notice that the left lens is nearly

6:59

completely gone compared to the right lens, which we can still see.

7:04

That's because this has less density than the normal right lens.

7:10

This lens that has lower density is typical of a traumatic cataract.

7:15

So let's bring that back together. One more thing.

7:17

We see this collection of air.

7:19

So that's another indication that this might be a ruptured globe with air pocket.

7:24

Sometimes we see air, as you see on the right side here,

7:27

That is just under the eyelid as a normal variation.

7:31

So it's kind of hard to tell.

7:33

But when you have this constellation of loss of the integrity of the cornea,

7:38

and the sclera, you have anterior chamber hyphema with anterior chamber rupture.

7:44

You have dislocated traumatic cataract lens.

7:48

Those findings, together with the eye,

7:50

with the extra air here, are all likely on the basis of trauma.

7:54

Notice that the vitreous is pretty much normal.

7:57

There's this one little area here which buckles inward,

8:00

which again is likely due to injury to the sclera and possibly the choroid

8:06

behind the globe, which is our retrobulbar space.

8:10

We see that the optic nerve and the retrobulbar fat is pristine.

8:14

There is no injury to there.

8:17

So this is all anterior segment injury.

8:21

The one thing I will also recommend that you look at carefully is the little

8:26

attachments of the lens to the lateral aspect of the globe.

8:30

This is, as I said, the uveal tract with the ciliary body.

8:34

When you see that that's obscured and you

8:36

don't have those small little lines connecting the two,

8:41

it's likely that the patient also has an injury to the uveal tract.

8:45

So, a lot of stuff on this image,

8:47

but it's basically all in the anterior most portion of the globe.