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The next congenital lung malformation we will discuss

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is the congenital pulmonary airway malformation or CPAM.

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This entity is essentially abnormal lung tissue due

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to some sort of rested alveolar development

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early in gestation.

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And importantly, these malformations

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communicate with the airway.

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There are many different types.

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There's actually zero through four.

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I will not be discussing zero and four,

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but I will be discussing one through three.

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Type one is generally considered macrocystic

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with larger cysts, two centimeters or greater.

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Type two, small to medium-sized cysts

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between half a centimeter to two centimeters,

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and then microcystic are tiny cysts

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less than five millimeters,

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and sometimes having a solid appearance.

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Because the cysts are so small,

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these lesions can regress prior to birth,

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so they can be detected sometimes on prenatal ultrasound.

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On screening examination, they may be followed by ultrasound

1:01

or fetal MRI and they may regress

1:04

and uh, be much smaller by the time of birth.

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On postnatal imaging,

1:10

these fluid-filled spaces eventually will be replaced

1:13

by air since these CPAs communicate with the airway,

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although the type threes can remain solid appearing again,

1:20

just because the cysts are so small, know

1:23

that these lesions can cause hyperinflation

1:26

or atelectasis of adjacent lungs.

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So when you're looking at postnatal imaging, be aware

1:31

that you can see this around the lesion.

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The first case I'll show you is a fetal MRI.

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If you're not used to reading fetal MRIs, the majority

1:42

of the sequences that we get are T two images.

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So all the rules that you know about T two

1:47

imaging apply here.

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Here we have axial coronal and sagittal images of the fetus.

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You can see on this coronal image, for example,

1:57

that the fetus is surrounded

1:58

by T two hyperintense amniotic fluid.

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And what's really helpful about these T two images

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for fetal imaging is

2:05

that future air-filled spaces are all filled

2:09

with fluid at this time.

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So they will be bright with bright T two signal

2:13

and that's very useful for us when we're trying

2:15

to determine normal versus abnormal structures.

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I'll start with the axial images on your viewer.

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You probably will have to uh, rotate

2:25

or flip the images with your tools

2:27

because oftentimes when we image these babies,

2:29

they're swimming around and moving

2:31

and so we can't get orthogonal views as we're used to.

2:33

So you will probably have to manipulate the images.

2:36

Here I have the axial images

2:40

and I'm gonna scroll from the top of the chest down

2:44

and we can see that on these images the heart is dark,

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which we expect, and we can see the right lung here

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and the left lung here

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and we can immediately see

2:55

that they look asymmetric to each other.

2:57

They're not the same shade of gray.

2:59

And while it takes some practice to get used to

3:01

what normal intensity is for fetal lungs,

3:05

at the very least you can tell

3:06

that these are asymmetric from each other.

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The left side looks larger than the right side.

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The left side is more hyper

3:13

intense compared to the right side.

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And additionally we can see more focal hyperintensity

3:21

in the central portion of that left lung.

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And so now I'm scrolling down just for reference

3:26

as we get into the fetal abdomen, we can see the liver here

3:29

and the stomach here and the tops of the kidneys here.

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This is the spine. If we go to the coronal images,

3:37

we'll see something similar.

3:40

We see the anterior part of the chest with the heart here,

3:44

the liver here, and the stomach fluid filled stomach here.

3:47

And as we go posteriorly again, we see

3:50

that the left lung looks hyperinflated compared

3:53

to the right lung and we see some more focal hyperintense

3:57

fluid-filled structures centrally.

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And then finally looking at the sagittal images

4:05

as we scroll over to the left side,

4:07

it becomes really obvious that there's a demarcation

4:10

between this more posterior hyperinflated part of the lung

4:14

that's hyperintense versus more anteriorly.

4:17

That portion of lung looks more hyperintense.

4:21

So when you see something like this,

4:23

particularly when you see these more focal cystic

4:26

components, one of the things

4:28

that you should be thinking about is CPA congenital

4:31

pulmonary airway malformation.

4:34

This patient went on to have postnatal imaging and

4:39

whenever you suspect some sort

4:40

of congenital lung lesion on prenatal imaging,

4:43

it is important to get postnatal imaging, particularly

4:46

to get a CT angiogram.

4:48

And I'll explain why more when we talk about broncho

4:52

bronchopulmonary sequestration.

4:55

Here we have the postnatal CT angiogram where we have

4:59

axial soft tissue and lung windows as well as coronal

5:02

and sagittal soft tissue windows.

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And I'm going to focus on the soft tissue axial images here.

5:09

And we can see that in that left lung there's a little bit

5:14

of soft tissue density posteriorly, but not too much else.

5:19

If we go to the lung windows, we'll see that

5:21

that soft tissue density is associated

5:23

with some air-filled cysts

5:27

and some adjacent hyperinflation.

5:31

So this turned out to be A-C-P-A-M with cystic components

5:36

that regressed substantially between the time

5:39

of the fetal MRI and the postnatal ct.

5:44

This cystic component likely corresponds with

5:46

that more focal T two hyperintensity

5:48

that we saw centrally on the fetal MRI.

5:50

And some of this around it might be a combination, um, of

5:55

microcystic, more solid appearing

5:57

Malformation and or atelectasis.

5:59

And then as I mentioned earlier,

6:02

you can have adjacent hyperinflation of the lung.

6:06

We can see similarly if we change our windows on the coronal

6:10

images, multiple small cystic spaces

6:14

adjacent more solid appearing tissue,

6:16

which may be a combination of elects as well as both solid

6:19

or microcystic portions of the lesion.

6:21

And then adjacent hyperinflation.

6:23

And then again on the saal images,

6:28

we can see similar findings with demarcation

6:31

of the normal boundaries of the major fisure right here.