0:00

Next we'll talk about a few different entities

0:03

that are congenital large airway disorders.

0:07

I'll show you a case of piriform aperture stenosis,

0:11

Choal latricia, which can seem similar

0:13

but is a different entity, tracheal stenosis

0:17

and tracheal bronchia.

0:20

This first case is a case of piriform aperture stenosis.

0:24

This is a patient that had the classic history

0:26

of difficulty breathing while eating,

0:29

and so this patient got a CT scan

0:31

and we can see here on the axial bone windows

0:35

that at the anterior aspects of the nasal passageways,

0:39

there is medial deviation of the anterior magilla.

0:44

So right in here, it's bowed in too much on both sides.

0:49

This is bilateral in this particular patient,

0:51

which is having the effect

0:53

of narrowing the nasal passageways at that level,

0:57

and we can see those nasal passageways

1:00

as they open up more posteriorly.

1:03

So this is piriform aperture stenosis bilateral.

1:06

In this particular case,

1:08

they can be unilateral in some cases.

1:12

This finding is associated

1:13

with a solitary median maxillary central incisor,

1:17

and when that's present, you should be hunting around

1:21

for more clues for other midline abnormalities,

1:23

particularly in the holo pro cephalic spectrum.

1:27

This particular patient did not have that.

1:29

We can see that they have two central incisors

1:33

as we would expect, not one single central mega incisor,

1:37

but that is something to look for if you do have a case

1:39

of piriform aperture stenosis.

1:43

The next case is a patient with choanal atresia,

1:48

and this entity is often taught

1:50

with piriform aperture stenosis

1:52

because they sometimes clinically can appear similar,

1:55

however, whereas piriform aperture stenosis was obstruction

1:59

at the level of the anterior nasal passageways.

2:02

This is obstruction

2:04

of the posterior nasal passageway

2:06

in this particular patient.

2:07

It's on the right side only,

2:10

so you can see on the normal left side how

2:11

that nasal passageway is wide open posteriorly here,

2:16

whereas on the right side it's narrowed.

2:19

You can see again pinching in of the magilla

2:23

and the vomer right here,

2:25

and you can see an associated air fluid level, and that's

2:28

because there's a complete obstruction right here.

2:31

So if one were to try

2:33

and place an NG tube through that, right,

2:36

it would not be able to pass.

2:38

This obstruction can be completely bony

2:41

or it can be membranous or a combination.

2:44

In this patient, we probably have a combination.

2:46

It looks mostly bony,

2:47

but there's a little bit that doesn't look like it's

2:48

completely ossified, so that's probably membranous,

2:51

but again, we often have this air fluid level.

2:54

Sometimes patients are diagnosed a little bit later in life,

2:57

especially if it's unilateral

2:58

With recurrent purulent material

3:00

coming out of that merits.

3:03

This can also be bilateral in some cases as well,

3:06

and oftentimes when it is bilateral, it can be associated

3:09

with other congenital anomalies.

3:13

This next case is a case of tracheal stenosis.

3:16

It can be difficult sometimes in young patients

3:20

and babies who are very small,

3:22

and if the image slices are a little thick,

3:24

you might blow past it if you don't

3:26

realize what you're looking for.

3:28

Here, for example, is a baby

3:30

who had congenital tracheal stenosis due

3:33

to complete cartilaginous rings

3:35

and on the coronal reconstruction,

3:37

if you look at the airway up here

3:39

and scroll through, it seems to look like it's painted,

3:43

although as you go down a little lower,

3:45

it does seem like it's a little bit wider in the distal

3:48

trachea, but if you're not paying attention,

3:50

you might not notice it.

3:51

Similarly, on the coronal reconstruction,

3:55

if you're not paying close attention,

3:56

you might not realize there is a difference in caliber

3:59

between the upper part of the trachea

4:01

and the lower part of the trachea,

4:03

so it can be really helpful if this is the clinical question

4:06

to make 3D reconstructions.

4:10

So if there's a clinical suspicion for tracheal stenosis,

4:12

it can be helpful to have your technologist make a 3D

4:16

reconstruction for you, where now we can see very obviously

4:20

there is a focal stenosis of the trachea

4:24

and you can even get spinning images.

4:27

If you have a subtle case

4:28

and you're not totally sure tracheal stenosis can be

4:31

congenital or acquired.

4:33

In the pediatric patients we see both,

4:36

but again, in this case, this was a congenital etiology.

4:40

Finally, I'll show a case of tracheal bronchia.

4:44

This is another entity that can be congenital or acquired,

4:48

and this is defined as a decrease in cross-sectional area

4:51

by at least 50% during expiration.

4:56

In this particular case,

4:57

this patient had congenital tracheal broncho malacia,

5:01

and this is a protocol

5:02

where I'm not showing all the raw images,

5:04

but it's a dynamic four D airway protocol

5:07

where we image the airways over time in order to get a sort

5:12

of semi clip of

5:13

what the airways are doing over multiple respiratory cycles.

5:17

I'm only showing you here the 3D reconstruction

5:20

to fully illustrate how much the airways, particularly

5:23

that left bronchus collapses during expiration

5:27

as compared to inspiration.

5:30

Not every institution necessarily has this protocol,

5:33

but it's something that you can investigate

5:35

further if you're interested.

5:37

Just know that this can be very useful when trying

5:39

to either qualitatively

5:41

or quantitatively evaluate for airway collapse.