0:00

Okay, we're gonna move, uh, more inferiorly into the body

0:03

and cover neonatal chest now.

0:06

So the most important thing is to know when

0:09

to call an x-ray normal in an infant.

0:12

And that can be challenging

0:13

because most of the time normal newborns don't come to x-ray

0:17

or any imaging for that matter.

0:19

They just have their newborn physical

0:21

exam and then they move on.

0:22

At our institution, almost always an infant is going

0:25

to have some sort of a support device placed,

0:28

and then they all have these clamps at

0:30

their umbilical stump.

0:32

So just remember that that is always going

0:34

to be present if you can see the upper abdomen

0:36

on your chest radiograph.

0:38

And don't confuse that for pathology.

0:40

So unlike in adults where they say

0:42

that the cardiac silhouette should be, um,

0:45

no larger than one third of the diameter of the chest,

0:48

in infants who have typically low lung volumes

0:51

because they can't take a big deep breath

0:53

and hold it for us, and then we're imaging them portably

0:56

from anterior to posterior approach rather than posterior

0:59

to anterior approach, the cardiac silhouette is gonna be

1:02

closer to 50% the transverse diameter of the thoracic, um,

1:06

cavity on a supine frontal view of the chest.

1:10

So the most important thing is to make sure

1:13

that your trachea is midline as long

1:15

as your patient is not rotated.

1:16

And we look at our clavicles to make sure

1:18

that the patient isn't rotated.

1:19

Make sure our ribs are symmetric in appearance.

1:22

Make sure your lung volumes are symmetric.

1:24

There's gonna be a little bit of, um,

1:26

what looks like vascular crowding in a lower volume,

1:29

um, chest radiograph.

1:30

But um, certainly no focal opacities, no pleural effusions

1:33

and no abnormal lucencies.

1:36

Oftentimes the clinicians will include the abdomen,

1:39

so you'll get an, a radiograph of the chest, abdomen,

1:42

and pelvis altogether.

1:43

Um, but you can always see the upper abdomen.

1:45

So make sure you pay close attention

1:46

for any unexpected findings there.

1:49

Um, one thing that we use

1:50

to help us if we don't have any history

1:53

or if the clinical team is unsure the gestational age

1:56

of the infant is in order

1:58

to tell if its infant is term or not.

2:00

We will look closely to see if we see any ossification

2:03

of the humeral head epiphysis.

2:05

If we see some ossification of the humeral head epiphysis,

2:08

we know the infant is term.

2:10

So if that epiphysis has started to ossify, you know,

2:13

you have a 38 week gestational age infant or older.

2:17

Unfortunately, if you don't see the humeral head epiphysis,

2:21

you can't tell the gestational age

2:22

because not all infants start

2:24

to ossify the humeral head epiphysis at 38

2:26

weeks gestational age.

2:28

So if you don't see the humeral head ossification center,

2:31

you don't know how old the infant is

2:33

or the gestational age of the infant,

2:34

but if you do see it, you know you have a term infant

2:37

and then you can steer clear from lung disease at premature

2:40

type diagnoses and you can focus on other diagnoses.

2:44

Most of the time when we have an infant in the nicu,

2:46

there's going to be support devices.

2:48

And so we wanna make sure number one,

2:50

that any support device placed is

2:52

going to be in the correct spot.

2:54

And I want to remind you the normal anatomy.

2:56

I love this article from aki,

2:58

Um, in Cincinnati, she, uh, went through looking at x-rays

3:03

and kind of overlayed the normal vascular structure

3:06

so we can know where a normal support device should be.

3:09

So a reminder that we only have one umbilical vein,

3:13

but we have two umbilical arteries.

3:15

So the umbilicus is kind of off

3:17

to the side here in this graphic.

3:19

The umbilical arteries join with the iliac arteries

3:22

to come up to the, uh, left-sided abdominal aorta.

3:26

The umbilical vein goes

3:28

through the umbilical vein into the umbilical recess.

3:30

It joins up at the, uh, umbilical segment, left portal vein,

3:35

and then blood in utero is diverted like through the liver,

3:39

through the ductus venosus.

3:41

And that joins up right near the confluence

3:43

of the hepatic veins at the lower

3:45

Cabo atrial junction level.

3:47

So if you can see an umbilical arterial catheter

3:49

or an umbilical venous catheter, make sure

3:51

that they follow the expected course of these,

3:55

uh, vascular structures.

3:57

So normal line placement in an infant.

4:00

Um, the vast majority

4:01

of our patients in the NICU are gonna be premature infants

4:04

with surfactant deficiency

4:06

or some sort of respiratory distress.

4:08

So the most common support device is an endotracheal tube,

4:11

which you want to be in the mid-thoracic trachea.

4:14

Um, I just kind of look at the,

4:16

where I expect the thoracic inlet to be near the level

4:19

of the clavicular heads through the level of the rin,

4:22

and I want it to be about in the middle of that.

4:25

Infants especially have a lot of movement

4:27

of the endotracheal tube tip

4:28

with chin positioning head up versus head down.

4:31

So just a little bit of change in positioning changes the

4:35

location of the tip of the endotracheal

4:36

tube quite significantly.

4:38

So I will report that if I see a chin down

4:40

and the endotracheal tube is low lying, the tube goes down

4:44

as the chin goes down, the tube tip

4:45

goes up as the chin goes up.

4:47

So I will say low lying endotracheal tube in the setting

4:50

of chin down or something like that.

4:52

So the neonatologists know like, okay,

4:54

maybe it's just positioning of the head

4:56

and that's why it looks like it's low.

4:58

The other super common device that we're gonna see,

5:01

and basically all

5:02

of our infants in the newborn nursery is an

5:04

enteric tube of some sort.

5:06

Usually there opal type tubes.

5:08

Um, they could be, uh, like feeding type tubes

5:11

or, uh, at our institution they use something called a Nava

5:14

catheter, which takes into account the electricity

5:18

of the diaphragm

5:19

to coordinate the timing of the enteric tube.

5:21

With the timing of respiration, um, that has a little bit

5:24

of a different weightier line anyway.

5:26

We mostly want the enteric tubes tip

5:28

to be right over the gastric body level if you have a

5:31

lateral view to confirm that it's, uh,

5:33

overlying the gastric body.

5:34

That's helpful. Last

5:36

but not least, this is an example

5:37

of a normal umbilical venous catheter.

5:40

So again, we have one umbilical vein when we're born,

5:43

the catheter should go through the umbilical vein

5:44

through the umbilical recess.

5:46

Join up, go through the ductus veno,

5:49

and then the tip ideally should be in the very inferior

5:52

aspect of the right atrium.

5:54

A reminder on the frontal view, it can look

5:56

Like a UVC is in the IVC in the inferior vena cava,

6:00

but if you have a lateral view, you can see that anterior

6:04

to posterior course of the catheter

6:05

as it goes from the level of the amus

6:08

through the umbilical vein, through the ductus ocm.

6:11

And then the tip should be in the low right atrium.

6:13

So this is what a normal support devices should

6:16

look like in an infant.

6:18

There's lots of things

6:19

that can go wrong with support devices.

6:21

So this image on the left,

6:23

you're gonna see this image a little bit later.

6:25

So this is an endotracheal tube.

6:27

This is a gas distended esophagus.

6:30

And these loosen, uh,

6:32

lines in this catheter here let us know

6:34

that this is a opal type enteric tube,

6:37

not an endotracheal tube.

6:38

So this enteric tube is stuck in a gas distended

6:41

proximal esophagus.

6:42

It's not extending into the stomach.

6:44

So probably this infant has esophageal atresia.

6:47

Not only that arm umbilical artic catheter is okay,

6:49

it is ending at the 1 2, 3, 4, 5, 6, uh, kind

6:53

of six seven disc space level on that left side.

6:56

So normal left sided descending

6:58

drastic aorta in this patient.

7:01

You don't want those to be too high

7:03

and you don't want them to be at the

7:04

level of the renal arteries.

7:05

You want it to be either above or

7:07

below the level of renal arteries.

7:08

So a high position is okay, a low position is okay as long

7:12

as it's not so high that it's going out like the subclavian

7:15

arteries or something like that.

7:17

But you don't want the tip to be at the level

7:18

of the renal artery

7:19

because then when the, whatever they're injecting will go

7:22

into the renal artery,

7:23

into the renal vasculature rather than, um,

7:26

in the systemic arterial supply through the aorta.

7:29

This left image last

7:30

but not least, has a low lying umbilical venous catheter.

7:33

So this is the, it's hard to tell where the umbilical, uh,

7:37

stump is, but we can see the umbilical

7:39

vein coming through here.

7:40

And this is, um, in the umbilical vein itself,

7:43

not at the level of the low right atrium.

7:46

So this is a, a magnifying view,

7:48

showing you the rego type enteric tube

7:50

in the cervical esophagus.

7:52

This black arrow is showing you a low lying

7:54

umbilical venous catheter.

7:56

This UAC umbilical arterial catheter is okay in position.

8:01

Another example of what can go wrong with catheters,

8:03

this is an umbilical venous catheter, is

8:05

that is extending into the right portal vein.

8:08

This is an example of a normal repo type enteric tube.

8:11

So we have our side holes

8:13

and the tip are projecting

8:14

below the diaphragm over the left sided stomach.

8:17

Um, so just a reminder in the vein,

8:19

the catheter could take a,

8:21

a wrong turn going right into the right portal vein as,

8:24

as in this example, um, some of the medications

8:27

that they use are particularly acidic or alkali

8:30

or they're, uh, very hyperosmolar.

8:33

And so it, you don't want your neonatologist

8:35

and nursing staff to inject anything that is, uh,

8:38

gonna cause localized damage to the liver prima itself.

8:41

So that's why they want it to be in the low right traum.

8:45

Um, so again, showing you

8:46

that umbilical venous catheter

8:48

projecting over the right portal vein.

8:49

And then the enteric tube is okay in this patient.

8:52

One more example of a low lying,

8:54

Um, umbilical venous catheter.

8:56

So this tip is projecting over the very superficial

8:59

umbilical vein, but there's one other important finding on

9:02

this image, which we can sometimes see

9:04

with attempted umbilical venous catheter placement.

9:07

And that is these branching lucencies

9:09

projecting over the liver.

9:10

So this is portal venous gas.

9:13

Now if you have a UVC that is newly placed,

9:16

don't freak out when you see portal venous gas

9:18

because it could just be related

9:19

to attempted umbilical vein placement.

9:21

Most of the time when we, um, see portal venous gas,

9:24

we get concerned that there's necrotizing enterocolitis

9:27

and pneumatosis has extended into the portal venous system.

9:30

When we see a normal bowel gas pattern, um, we're okay.

9:33

It's probably just related

9:34

to umbilical venous catheter placement

9:36

and in this case it's low lying.

9:38

So it's, it's almost certainly related to that UVC.

9:41

We'll talk more about, um, necrotizing enter colitis.

9:43

Um, in the next section of this series, um,

9:47

this is just a magnified view.

9:48

Hopefully you can see these branching lucencies

9:50

of gas in the portal vein,

9:53

and that's just related to UVC placement.

9:56

One more. And that is this example

9:58

where basically every catheter

10:00

that can be abnormally positioned is abnormally positioned.

10:03

So this is our umbilical venous catheter in this patient.

10:05

It's a little on the high side projecting over

10:07

the mid right atrium.

10:09

This is an endotracheal tube, which is okay in position.

10:12

This is, uh, two different enteric tubes.

10:15

And we can see this patient has a gas filled right-sided

10:18

stomach, but these two enteric tubes are projecting over the

10:22

right upper abdomen.

10:23

So this is pretty concerning that

10:24

at somewhere along the course, this perforated

10:27

through the esophagus into the pleural space.

10:30

And so these tips are act

10:32

actually projecting over the far inferior,

10:34

posterior right pleural space.

10:36

So when you pick up the phone

10:37

and you call them to say, Hey, nicu,

10:40

these catheters are malpositioned.

10:42

Make sure they have a chest tube kit ready in case they need

10:45

to place a chest tube to plug up the hole

10:47

that these catheters caused in the pleura.

10:48

And this patient will develop a pneumothorax.

10:50

The good news in this case is this patient already

10:52

has a right-sided chest tube.

10:54

When you're looking at a chest tube in a newborn in the

10:57

nicu, just pay close attention not only to the location

10:59

of the coil, of the um, chest tube, the pigtail chest tube,

11:03

but look at where the side holes are.

11:05

So this one is subtly just right within the thoracic cavity.

11:08

So we'll pay attention to

11:09

what this side hole looks like on follow-up studies in this

11:12

very premature infant.

11:15

Let's move on now to, uh,

11:17

actually talking about lung disease in this

11:19

chest radiograph talk.

11:20

I know we, we talked about some abdominal findings, uh,

11:23

when we were talking about support devices,

11:25

but we lumped them all together so that, um, most

11:28

of the time you'll get a chest, abdomen, pelvis,

11:30

radiograph when they're,

11:31

when the question is support device.

11:33

So let's move on to lung diseases.