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Hello, and welcome to Noon Conferences hosted by MRI Online.

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In response to the changes happening around the

0:06

world right now and the shutting down of in-person

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events, we have decided to provide free daily

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noon conferences to all radiologists worldwide.

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Today, we're joined by Dr. Tony Filly.

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He is a community radiologist with specialty

0:16

training in fetal ultrasound and feels that fetal

0:19

ultrasound should be, should not be feared, but

0:21

it can be mastered by most general radiologists.

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He has won the Clinical Faculty Teaching

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Award twice at Stanford University.

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And a reminder that there will be time at

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the end of this hour for a Q&A session.

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Please use that Q&A feature to ask

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all of your questions, and we'll get to

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as many as we can before our time is up.

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That being said, thank you so much for joining us today, Dr.

0:37

Filly.

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I'll let you take it from here.

0:40

Thanks, Ashley.

0:41

Um, so today I'm going to talk about, um, basically

0:44

I put in quotes, a simplified approach to the OB

0:47

ultrasound because I think a lot of people struggle

0:52

to get this, um, or to feel comfortable with it.

0:56

I think there's a lot of reasons for that.

0:58

Um, one reason is I think people think of this study as

1:03

looking for all these crazy anomalies, like CCAMs and

1:07

holoprosencephaly and encephaloceles, and you're like, what?

1:10

I don't even remember what those are.

1:12

What do they look like?

1:13

And, and I think people get kind of bogged down

1:16

in that, and that it, it sort of paralyzes them.

1:18

Also, there's a big sort of issue between who's

1:23

going to scan these, OB doctors, radiologists.

1:26

Problem is, as radiologists, we're asked to do these, not

1:30

infrequently, and we may not always feel comfortable, so.

1:33

Part of what I want to do is simplify our approach, but also

1:36

what I want to do is, um, give you some tactics to not, to keep

1:41

yourself out of trouble in interpreting this type of scan.

1:45

So, you know, make sure you don't

1:47

end up in the courtroom, basically.

1:48

So we talked, you know, I mentioned that we are

1:51

looking for some of those crazy things, but really

1:53

what we need to focus on and where people honestly

1:57

get in the most trouble is just some basic stuff.

2:01

Like how many babies are there?

2:03

What, what are the, what's the size of the baby?

2:05

How does the amniotic fluid look?

2:07

Where's the placenta?

2:08

And is there a previa?

2:10

What does the cervix look like?

2:11

And yes, of course, we will cover the anatomic survey.

2:15

Um.

2:17

And I think, you know, just like with, um, other

2:20

studies, you know, you, you generally have a way to

2:22

organize. If you're a body radiologist, you're reading

2:26

abdominal CTs, or if you're a neuroradiologist,

2:28

you're reading a brain MRI or whatever you're reading.

2:31

There's generally a, a way that you have of approaching

2:34

that study, and it's probably going through your

2:38

report, dictating, you know, from an abdominal CT.

2:41

You're going to start at the lung base and go to the liver

2:43

and the biliary system and the pancreas, or whatever it is.

2:46

And in the fetal ultrasound, you're going to do the same thing.

2:50

And the problem is this report can look kind of daunting.

2:54

This is a standard OB ultrasound report, and there's

2:57

a lot of info in here, a lot of things going on.

3:00

Um, and unless you can really organize it

3:02

in your mind, it's going to be sort of hard.

3:04

So what I want to do is basically go through a

3:08

standard report, kind of line by line, talk about

3:11

what we're looking for, why we're looking for it.

3:16

Focus on what normal looks like.

3:18

And if you can identify normal and what's not

3:22

normal, you're going to be way ahead of the game.

3:25

So you don't necessarily need to know

3:26

what a holoprosencephaly looks like.

3:28

You just need to know what a normal brain looks like.

3:32

And then if it's not normal, you can do,

3:34

you know, refer it on to somebody else.

3:37

Um, so that first paragraph of the report basically says a

3:40

single living fetus is identified in cephalic presentation.

3:45

The placenta anterior without previa, the amniotic fluid is

3:48

normal, and the cervix and uterus and adnexae are normal.

3:52

So let's start with just the num, the word single.

3:56

This ends up causing people problems.

3:59

Um.

4:00

You, there are people who have missed twins.

4:03

It happens, and it's generally because someone who's not

4:07

skilled puts a transducer down, starts measuring things and

4:12

looking at the heart, and they never really went through

4:14

and counted the number of fetuses that are in there.

4:17

And if you just start your sonographers off by actually

4:22

doing a generalized survey of the uterus, rather than

4:26

just measuring things, you're going to, uh, avoid some of

4:30

these pitfalls that you see people get into trouble with.

4:33

If you think of it as counting heads, if you said

4:36

to someone, hey, walk in this room and count how

4:38

many people are inside that room, you would say,

4:42

you might go look behind the door, look under the

4:44

desk, you know, look around, make sure that you're

4:46

going to count the number of people in the room.

4:48

You want to approach a fetal ultrasound the same way.

4:53

So let's say you see more than one.

4:58

Uh, uh, baby in there.

5:00

Then we get into something that causes people, and I

5:03

see this causing people a lot of problems, and that's

5:06

ity and amnity, and it's really not that complicated.

5:10

I'm not sure why people struggle with it so,

5:13

so much, but I think part of it is because the

5:17

term ity and amnity sounds kind of complicated.

5:21

Um, but if you really just think of it.

5:23

You can, you kind of know what an amnion is.

5:25

It's an amniotic sac.

5:27

The baby's surrounded by an amniotic sac, chorion.

5:29

You know, you're kind of thinking,

5:30

oh, what's that thing from embryology?

5:32

It develops into this or that.

5:34

But if you really just replace the word chorion with

5:37

the word placenta, then it becomes a lot easier.

5:42

And while we're talking about sort of more second

5:45

trimester ultrasound stuff here, I'm going to just

5:48

backtrack for a second as an aside, because

5:50

this is super, super, super, super important.

5:53

And I do see people get into trouble with this.

5:55

So remember that the first trimester

5:58

is the best way to figure this out.

6:00

And the first trimester membrane is your friend.

6:03

And there's a very easy step process to

6:06

go through this, and we'll go through it.

6:08

Step one, is there a thick membrane? Answer?

6:11

Yes.

6:12

It's dichorionic, so it'll have two

6:14

placentas, diamniotic, it will have two

6:18

amniotic sacs.

6:20

Um, I don't get bent out of shape or worried about

6:23

all the dizygotic and how did the baby split.

6:27

You can learn all that from embryology, but this

6:29

is what you need to know to interpret the scan.

6:33

Step two is there a thin membrane?

6:35

Yes, it's monochorionic.

6:38

Diamniotic. Is there no membrane?

6:41

It's monochorionic monoamniotic.

6:44

And just remember that monochorionic monoamniotic

6:46

is actually really rare, so it's

6:49

more likely that just the resolution of your

6:53

transducer is missing a thin membrane.

6:56

Um, why is this so important?

7:00

Well, dichorionic diamniotic pregnancy, so dichorionic,

7:03

two placentas, and diamniotic, two amniotic cavities.

7:07

Those are like two babies kind of

7:09

living on their own, doing fine.

7:11

Just going to run into problems that

7:13

any other normal baby would find.

7:15

The monochorionic, remember chorion, placenta, one

7:19

placenta, those babies are sharing a placenta, and with all

7:24

siblings, you know, they don't often share it properly.

7:27

Um, they run into either what we call, um, unequal

7:31

sharing or twin-to-twin transfusion syndrome.

7:34

We won't go into what that is, but

7:36

it's very dangerous and very bad.

7:40

And you want to make sure you identify a monochorionic

7:44

diamniotic pregnancy and, and make sure that

7:47

you let them know that that's what it is, a mono.

7:50

Mono also runs into some transfusion issues and

7:53

cord entanglement, but again, that's kind of rare.

7:56

So let's take a case.

7:58

We see two.

8:00

Pregnancies, we see a thick, is there a thick membrane?

8:04

The answer is yes.

8:06

It's dichorionic diamniotic.

8:09

Um, the problem is, and we've said the first trimester

8:13

membrane, your friend, this thing is actually a

8:15

dichorionic diamniotic much later on in pregnancy.

8:19

And you see how it's gotten a

8:21

lot, um, thinner as time went by.

8:25

So you may hear like, oh, there's four layers.

8:27

I don't really, again, get really bent out of

8:30

shape about that or think about that too much.

8:32

But you have two chorionic cavities that will create two

8:35

placentas and two amniotic cavities, and then, um, that

8:40

it generates the four layers that you often hear about.

8:43

And then that membrane will

8:44

stretch over time and look thinner.

8:46

So you want to try and figure this out here.

8:50

One fortunate thing is that this

8:51

membrane does stretch asymmetrically.

8:55

So you will sometimes end up with this a

8:57

little thick here, but a lot thick here.

8:59

We call that the twin peak sign, and that's

9:02

something you can see a little later that will

9:05

let you know that this is still dichorionic diamniotic.

9:09

So it's not quite as thick, but

9:11

it's still thick asymmetrically.

9:14

Um, here we actually see, uh, no thick membrane,

9:19

so we know we're down into step two or three.

9:22

We don't really see a thin membrane, but

9:24

what we do see is, um, a little sac around

9:29

this guy and a little sac around this one.

9:33

And that's basically as these sacs grow,

9:35

we'll turn into this little thin membrane.

9:38

So we see here a thin membrane.

9:40

Yes, it's monochorionic diamniotic.

9:43

And we can see here, here's our one chorionic sac.

9:46

So this will become one placenta, and we have our two

9:50

amniotic sacs creating a thin membrane with only two layers,

9:54

and it stays sort of pencil-thin throughout pregnancy.

9:59

So di-di, mono-di.

10:02

Um, and, uh, this is the twin peak with no twin peak.

10:07

Um, what I like to, before we do that, what I

10:11

like to say is, you know, or what you want to

10:14

remember, is that if you identify one of these in

10:18

the first trimester, you want to dictate that this is

10:21

a monochorionic diamniotic pregnancy, and that these

10:25

babies need to be followed, starting at 16 weeks, for

10:28

the development of twin-to-twin transfusion syndrome.

10:31

Make sure you say that; that's

10:32

incredibly, incredibly important.

10:35

So this is kind of putting it all together.

10:37

What is this?

10:39

You have a thick membrane, so we know it's dichorionic,

10:44

but now we actually have three amniotic cavities.

10:47

So we've got one, two, three.

10:49

So this is dichorionic triamniotic.

10:52

So this is pretty complicated, but if you

10:55

just follow those rules, it's not too hard.

10:59

Uh, fetal lie is pretty simple.

11:01

We just describe what the lie is.

11:03

It's either, uh, some people use the term

11:05

vertex or cephalic, breech, transverse.

11:08

Um, that's really important for later in

11:10

pregnancy, for birth planning; we don't really

11:12

focus on it during the second trimester.

11:16

You can use it to, to sort of decide

11:18

what the situs of the baby is.

11:20

I don't spend a lot of time on that.

11:22

Um, what you really care about is whether the

11:24

fetal heart and the stomach are on the same side.

11:27

And we'll get into that a little bit later.

11:29

Talking about the heart, um, you want

11:31

to talk about where the placenta is.

11:33

So the next item in the report, the

11:34

placenta is anterior without previa.

11:38

So placental location: anterior, posterior, fundal.

11:41

This is just, again, more for, uh,

11:43

planning of birth and/or, uh, C-section.

11:47

Placenta previa has historically

11:49

been a little bit complicated.

11:51

We use the term marginal,

11:53

partial, complete, low-lying.

11:56

Different people had different, uh, definitions for these.

12:00

But, um, basically you have the cervix here.

12:04

This is the endocervical canal right here.

12:07

And this is the proximal portion.

12:10

This placenta is pretty close.

12:12

You would want to measure it.

12:13

It's sort of near the os.

12:16

This one, you have the cervix, sorry.

12:19

Um,

12:23

You have the cervical canal here.

12:24

This placenta's covering it.

12:27

You have the cervical canal here.

12:28

This placenta's covering it.

12:31

Um, I do just, uh, tip, have a very

12:35

low threshold for endovaginal imaging.

12:38

I'm sending the techs in all the time.

12:40

It'll look very different.

12:42

Endovaginally, many times.

12:44

So back in 2014, they actually did a consensus

12:48

panel and kind of simplified these terms.

12:51

Just return the terms placenta

12:53

previa or a low-lying placenta.

12:56

If the edge of the placenta is greater than two

12:59

centimeters from the internal cervical os, it's normal.

13:03

If it's less than two centimeters like this, but

13:05

not covering it, we call that a low-lying placenta.

13:10

And if the placental edge right here is overlapping and

13:15

covering the internal os, we call it a placenta previa.

13:19

I do like to at least describe, just

13:22

saying there's a placenta previa.

13:23

I might say there is an anterior placenta

13:28

with a previa. The tip of the placenta is extending, you

13:33

know, 12 millimeters beyond the internal cervical os.

13:37

So then at least someone knows what you're talking about.

13:42

Um, the recommendation is to follow these up at 32 weeks.

13:46

I would do it with EV at that time as well.

13:49

If it's still low-lying, you want to

13:50

follow it up again at 36 weeks.

13:52

But the obstetrician, by that time,

13:55

kind of knows what's going on.

13:56

And here's just kind of describing how, or kind

13:59

of some wording on how you might describe it.

14:02

You can definitely get faked out by,

14:05

um, lower uterine segment contraction.

14:07

So here's early on in the scan, it

14:09

looks like there's a low-lying placenta.

14:12

Later on in the scan, you see that the

14:13

placenta is all the way this far away.

14:16

A little tip if you're measuring the cervix.

14:19

So if someone decided to measure from here all the way to

14:21

here, if you're measuring something greater than five cm.

14:25

Most cervices, most cervixes are not that big, so you're

14:28

probably including a lower uterine segment contraction.

14:31

If you've, um, done that, um, if you're not sure whether

14:36

there's a low lower uterine segment contraction, you can

14:38

always just say, I'm not sure this is a low-lying placenta.

14:41

The evaluation was limited by a lower uterine segment

14:44

contraction, and I just recommend a follow-up.

14:47

There's something called a vasa previa,

14:49

which you really want to know about.

14:52

This is when a fetal vessel actually overlies the cervix.

14:57

So there's a vasa vessel previa, and the, the reason this is

15:01

important is because a baby's, this is fetal blood in here.

15:05

This is probably maternal vein here in the cervix.

15:09

So when the, during delivery, if one of

15:11

these vessels ruptures, if the mother

15:13

loses 50 cc of blood, it's no big deal.

15:16

If the baby's vessel ruptures and they lose 50 cc

15:19

of blood, that's a big portion of their blood volume.

15:22

So this can be catastrophic.

15:25

Um, and what I always, uh, instruct our techs to do is

15:29

just take a picture like this, overlying the cervix in

15:33

each case, and make sure there's no blood vessels there.

15:36

The way that, you know, the difference between

15:39

maternal and fetal is by putting a spectral tracing.

15:42

You see the, the heart rate is 131 beats per minute.

15:46

The mom probably has a heart rate of,

15:48

you know, 80, 90, or something like that.

15:50

So, you know, this is a fetal blood vessel

15:52

unless the mom were tachycardic for some reason.

15:56

Placenta accreta is another thing.

15:58

We're not going to go into it a lot, but I just want

16:00

you to know, again, it, it can be hard to diagnose.

16:04

But the thing you need to know is if you say the

16:08

words, there's a low-lying anterior placenta or

16:12

a placenta previa, and the placenta is anterior.

16:18

You may or may not know whether the person has had a

16:20

C-section before, but that's what places the person at

16:23

risk for an accreta, and the accreta can be very bad.

16:29

So all you need to know is if you see an anterior

16:32

low-lying placenta or a previa, just dictate,

16:35

if the patient has a history of C-section,

16:37

recommend close follow-up to assess for accreta.

16:40

That'll put it into someone else's court.

16:42

You don't necessarily need to look for it, but

16:45

you've identified that the patient's at risk.

16:49

Um, next thing in our report, quantitative

16:51

amniotic fluid is within normal limits.

16:54

There are two ways to assess amniotic fluid,

16:57

sort of the gestalt, how does it look?

16:59

And then some people would say quantitative.

17:01

I'll say semi-quantitative because it's not that great.

17:05

The gestalt method is kind of what everyone does.

17:07

You kind of look at it and you're

17:07

like, yeah, that looks about right.

17:10

But people don't really know why it looks right.

17:13

And the re-, the way you know it looks right is

17:16

if the head and the abdominal and thoracic cavity,

17:20

sorry, and the abdomen and thorax are filling

17:22

the amniotic cavity, but there are communicating

17:26

pockets of fluid between the small parts.

17:28

You know, the arms, the legs, around the face.

17:30

That's normal fluid.

17:31

That's what your eye is telling you is normal.

17:35

Here we've got some portion of the baby, probably the thorax

17:38

or something, and here's the anterior wall of the uterus.

17:41

There it is, not even coming close to filling the cavity.

17:45

So right there you're thinking this is probably polyhydramnios.

17:49

Maybe I'll go in and measure something.

17:52

So the two ways to measure are the amniotic

17:54

fluid index and the deepest vertical pocket.

17:57

I think people get hung up on these

17:59

as really hard and fast numbers.

18:01

Just remember the baby's moving.

18:03

So you might measure one area one time and the baby

18:06

moves, and you know that fluid's sloshing around in there.

18:09

So the amniotic fluid in

18:14

the deepest pocket, that's at least one centimeter wide.

18:17

So don't measure some little sliver, um, that's

18:21

tiny, thin, but long, and call that a pocket.

18:25

You want to place color Doppler on each one, so

18:27

make sure there's not cord filling that area.

18:30

And then measure the vertical depth

18:32

with the transducer in that pocket.

18:35

And the numbers I use, there are some

18:37

charts you can pull up, but if you kind of

18:39

go with five and 25 for oligohydramnios or

18:42

polyhydramnios, you're going to be in good shape.

18:46

Um, the deepest vertical pocket, kind of

18:48

same rules you're going to find; you're going to

18:51

look for the deepest pocket and measure it.

18:54

Less than two is oligo, and greater than eight is poly.

18:57

These are actually shown to be just

18:58

as good as the amniotic fluid index.

19:02

So tips to keep you out of trouble.

19:06

If gestalt-wise you're thinking, hmm, this fluid looks

19:10

low and you're going to measure it, um, that's great.

19:14

This is usually going to happen in the third

19:16

trimester, but you're suspecting oligo, and

19:20

let's say if you get an amniotic fluid index

19:22

of 4.4, you're going to say, oh, that's oligo.

19:24

It's less than five.

19:25

Let's say you get a pocket of 1.3, 1.4, 1.71, and

19:29

0.8, and you get 5.2. At this point, this two millimeters

19:35

of extra fluid here that you just measured.

19:39

In a baby that's moving around, that does

19:41

not sort of confer any safety upon the baby.

19:45

The, the difference between 4.9 and 5.2, that's

19:48

three millimeters of fluid, is not, you know, that

19:53

doesn't mean that everything is just hunky-dory.

19:55

So make sure, if you're worried about this, I would still,

20:00

you know, start raising red flags here to the doctor.

20:03

Don't just go strictly by the number when it comes to oligo.

20:07

Um, if you do see a pocket of greater than 2.5 and you're

20:11

hovering in the low fives, it's probably okay,

20:16

but just make sure you don't send that patient home.

20:19

I always keep them there.

20:20

Let the doctor know there's oligo and usually

20:24

send them to the birth center to get some testing.

20:28

Poly is important, but not as time-critical as oligo.

20:31

You don't necessarily have to hold the base patient there.

20:34

The most common causes are, um, large babies, uh,

20:38

mother with maternal diabetes, something like that.

20:41

This is generally occurring in the third trimester.

20:43

There's a whole list of things,

20:44

anything that blocks the flow of fluid.

20:46

So blockage of fluid within the, in

20:49

the GI tract, esophageal atresias, chest masses.

20:52

The fluid can't get into the, um,

20:55

GI tract, so the baby can't swallow.

20:56

They've got a CNS anomaly or something like that.

21:00

But again, poly is, is more of a, we're not going to

21:03

go into the whole differential, but you just

21:05

want to, again, identify these things, learn how

21:07

to identify them, and be able to refer them on.

21:11

Um, obviously we're going to measure the cervix.

21:13

Anything greater than three centimeters is normal.

21:15

Again, if it looks borderline, low threshold for EV scan.

21:21

Um, we, you know, the next two lines are, the uterus

21:25

is within normal limits, no adnexal abnormalities.

21:28

We just want to look for large myomas.

21:31

They can grow a lot under the

21:32

hormonal, um, situation in pregnancy.

21:36

So if there's lower uterine segment myomas,

21:39

you want to let them know that you might be

21:40

running into an issue for vaginal delivery.

21:43

Um, you know, you can see malignancies during

21:46

pregnancy, so you just want to make sure I'm not having

21:49

the techs measure the ovaries or take, you know, a

21:51

bunch of pictures of them, but you want to just swing

21:54

out there and make sure there's no big adnexal mass.

21:57

Um, next we come to biometry.

22:00

That's that whole biometric table of all the measurements.

22:03

And what you want to know here is how to

22:07

measure them, what the landmarks are.

22:10

How to do it correctly and make sure that your

22:13

techs are doing it the same way every time.

22:15

I see people screw this up, uh, constantly.

22:20

And the important thing is, is that very crucial

22:23

decisions may be made based on these measurements.

22:27

You don't need to, you know, sometimes it is hard to get

22:30

the obliquity just right or something, but you need to

22:33

know if you know how to, it's supposed to be done and

22:37

you can recognize how it was done improperly and how

22:41

much it was done improperly, then you sort of know, like,

22:45

the magnitude and direction of the error that occurred.

22:49

So if the baby's measuring too big, and

22:52

we'll get into that in a little bit.

22:54

You look back like, well, they, they measured the

22:57

abdominal circumference, you know, too obliquely.

22:59

So they overmeasured it.

23:01

So I'm not going to get too bent

23:03

out of shape about that measurement.

23:05

Um, but you don't need to go back and fix

23:07

every slight error; that would take forever.

23:09

It's just, it's hard to get these sometimes.

23:11

So give your techs a little bit

23:13

of a, a break there, but just

23:18

people use all kinds of different biometric measurements.

23:20

But the head circumference, biparietal diameter, abdominal

23:23

circumference, and femur length are the four major ones.

23:27

The head circumference criteria, you

23:30

want to see the cavum septi pellucidi.

23:33

You want to see the thalami right

23:35

here, flanking the third ventricle.

23:38

And you want to see the tentorium.

23:42

Right here.

23:42

And it sort of forms, people say, like, kind of forms an arrow.

23:45

So this is the arrowhead, and there's

23:47

some feathers coming back here.

23:49

Um, you want to measure as tight as you can to the bone.

23:52

You can see here they didn't do

23:53

it perfectly, but that's okay.

23:56

You just need to know, like, oh, maybe they over-

23:59

measured a little bit, and back here you want to

24:02

make sure they don't include the cerebellum.

24:04

That would be too oblique.

24:06

I don't know if you can see me on this video,

24:07

but instead of measuring like this, you're

24:09

kind of measuring it too much like this.

24:11

So you're going to, that would cause an overmeasurement.

24:16

Um, the errors I see again.

24:19

Including the cerebellum, making it too big, uh, maybe,

24:23

uh, measuring outside to the skin instead of as

24:25

tight as you can to the bone.

24:28

So what I want you to take away from this

24:30

is how do I know they did it right or wrong?

24:34

Um, the biparietal diameter is kind of the same, same landmarks.

24:38

You can, a lot of people use the same image, cavum, thalami,

24:43

but back here it doesn't really matter because you're only

24:46

measuring basically the width of the, of the head here.

24:50

So some people measure from the bone to the

24:53

bone, some people measure from the outside

24:55

of the bone to the inside of the bone.

24:57

You just need to know how you guys do it, how people do

25:00

it each time, and make sure that this landmark is here.

25:04

And this landmark is here.

25:07

The abdominal circumference.

25:09

Um, you're going to look for this, this is

25:11

basically the portal venous confluence.

25:13

What some, some things that kind of.

25:15

Tweak people out with OB ultrasound is that the baby

25:18

is in all sorts of different positions all the time.

25:22

So, you know, when you're looking at, say, the left

25:26

portal vein here, it's actually on the right side.

25:28

It should be up, you know, it's not like the liver

25:30

in, in a CT scan where it's always in the same place.

25:34

So you just want to know this, this has, this is a

25:36

really nice picture, so it's got all these other

25:38

vessels, but you're looking for this sort of, like,

25:40

hockey-stick-shaped thing with the stomach.

25:45

You want to make sure the ribs are symmetric.

25:47

This is the left portal vein.

25:49

This is the umbilical vein.

25:50

You want to make sure that the umbilical

25:52

vein isn't really stretched out here.

25:55

Um, and you want to measure to the skin.

25:59

And the, the, the things I see

26:00

people doing this is too oblique.

26:03

You'll see this stretched way out here.

26:06

Um, you know, sometimes it's hard to see where the skin

26:09

ends, and people start including stuff all the way back here.

26:13

Um, so again.

26:15

Take away what it's supposed to look like and

26:18

then, um, uh, and then know what went wrong.

26:22

And in the third trimester, this is probably

26:24

the hardest measurement to get, but just

26:26

remember one thing that's a nice tip.

26:28

If you can get it to be round, you're

26:30

probably, you know, you're making up for a

26:33

multitude of other issues that you maybe have.

26:37

Um, for the femur, you just want to make sure you're measuring

26:40

only the ossified femur, which is the white part right here.

26:44

This is the femoral head.

26:45

Cartilaginous still, it hasn't been ossified.

26:48

This is the—I'm sorry—this is the femoral head.

26:50

These are the femoral condyles, sorry.

26:52

So femoral condyle is femoral head.

26:54

So you want to make sure you're not including this.

26:57

This area right here can sometimes cause a reflection,

27:02

and you get something called the distal femoral point,

27:05

and people will start including this in the measurement.

27:09

You just want to watch out for that.

27:13

And then you'll generate this thing, the biometric

27:15

table, which is filled with all kinds of information.

27:18

But you really want to focus on a couple things here.

27:21

Mainly, you want to look at what your gestational

27:24

age is that you're basing your study on.

27:26

So it could be by last menstrual period, or it could

27:28

be by an early first-trimester ultrasound here.

27:31

They just happen to be the same; they're 32 weeks.

27:34

The ultrasound, um, that we

27:37

calculated was 31 weeks, four days.

27:39

So this is within seven days.

27:41

So we say size is consistent with dates.

27:45

You're going to look down at the weight percentile.

27:48

Um, again, on different machines, this

27:50

comes out in different ways, but this

27:53

is 52nd percentile, so that's great.

27:55

You can also make sure that none

27:57

of these are way out of whack.

27:59

Um, you know, this one's getting kind of low, but you want to

28:03

make sure none of these—but I focus mostly on this and

28:06

this, and I think if you do that, you'll be in good shape.

28:09

In this one, we see this as 32 weeks, four days,

28:12

but the baby's measuring 34 weeks, two days.

28:16

So this baby is actually, uh, 12 days greater than dates.

28:21

You look down at the weight percentile,

28:23

you're like, oh, it's in the 84th percentile.

28:25

So this baby's getting pretty big.

28:27

So you want to suggest continued

28:29

follow-up to assess for growth.

28:33

So that's kind of a, a, you know, a run

28:37

through all the things you really want to

28:39

mainly focus on for the whole assessment.

28:44

Now we're going to get into the anatomic assessment.

28:47

I'm not going to show you a ton of pictures.

28:48

I'll show you some pictures, but I'm not going to show

28:50

you crazy pictures of all these weird anomalies.

28:52

Again, just like with, um, you know, reading, uh.

28:57

Shoulder MRI or an abdominal CT.

29:00

Once you know what normal looks like, your eye

29:02

will pick up what's abnormal, and you don't

29:05

need to know every fetal anomaly under the sun.

29:09

If you just say, hey, I'm not seeing this.

29:14

Go get a, uh, you know, a level two scan or a

29:17

go see a perinatologist or something like that.

29:20

You'll save yourself a lot of anxiety and, and really

29:24

be good in doing the right thing, um, for the mother.

29:28

So we're going to just go top down.

29:30

Um, we'll start with the head and brain anatomy.

29:33

There's basically, um, there's several things

29:36

listed in there, but there's a few things you

29:39

really want to focus on, and what I, you know.

29:42

Make sure they take a, a, a picture of the

29:44

cerebellum with the cisterna magna, the cavum

29:48

septi pellucidi, and the lateral ventricle with the choroid.

29:51

And I'll just put in a plug here.

29:53

Cine clips are definitely your friend in ultrasound.

29:58

Um, I have them take a cine

30:00

clip through all three of these.

30:02

Um, some people think, oh, the less

30:04

pictures I take, that I'm not as high risk or

30:06

something like that for missing something.

30:08

That is not the case.

30:10

The more pictures you take, the more

30:12

chance you're going to find something.

30:14

Because if you didn't take a picture of it and

30:16

you were supposed to, that doesn't help you.

30:19

Um, so let's look at some of these things.

30:22

So I'm going to go by, I'm going to go through what

30:24

the picture is and why, what you're basically

30:29

trying to rule out with each of these pictures.

30:31

So the cerebellum and cisterna magna, here's the cerebellum.

30:35

Right here.

30:36

Here's the cisterna magna.

30:37

We're basically using this to exclude a Dandy–

30:40

Walker malformation, which is vermian agenesis.

30:43

Here's the cerebellar vermis; it's there.

30:45

So that's good.

30:46

And we're going to exclude a Chiari malformation, which

30:49

is when the cisterna magna is completely effaced

30:52

and the cerebellum is being sort of sucked down in.

30:56

Um, I don't measure the cisterna magna

30:59

in every case. You'll kind of determine, your

31:02

eye will just tell you that looks normal over time.

31:05

If it looks greater than 10 millimeters,

31:07

let me tell you, that looks huge.

31:09

And, you know, you can have your tech

31:11

measure it every time or not measure it.

31:13

It doesn't really matter.

31:15

Um, like I said, here's normal.

31:18

Here's what a big one looks like.

31:19

It's gigantic.

31:23

Um, what you want to know when you, what you want to

31:27

look at when you see a big cisterna magna.

31:30

You want to find the fourth ventricle, and hopefully all of

31:32

you are at least familiar with reading head CTs or brain MRIs.

31:36

So you see the fourth ventricle, there's tissue behind it.

31:38

There's the cerebellar vermis.

31:40

So the vermis is intact.

31:42

You can, you can confidently say this is

31:44

either a mega cisterna magna, just meaning

31:47

a big cisterna magna, or an arachnoid cyst.

31:50

Um, neither of those, you know, is going to

31:53

cause the baby a significant problem.

31:56

You know, congenitally, you know, a congenital malformation

31:58

that you need to worry hugely about, but you would want to

32:01

at least send it off to have someone else take a look.

32:05

What does the absent vermis look like?

32:07

It might look like something like this.

32:08

Here again, we see a big cisterna magna,

32:11

big cisterna magna, cerebellar hemisphere,

32:14

cerebellar hemisphere, cerebellar hemisphere.

32:16

And then that vermis, which we saw before, isn't there.

32:19

So again, you don't necessarily need to be able to

32:22

diagnose this, but you're going to see the big cisterna magna.

32:26

You're going to see the vermis being absent,

32:28

so you're going to have a pretty good idea,

32:29

and you're going to refer this patient on.

32:32

Um, here we don't see any cisterna magna.

32:36

This is not there.

32:37

So we're pretty confident this is, you

32:41

know, people call this the banana sign.

32:42

I don't like to use terms like

32:43

that, but you can, if you want.

32:46

Basically, there's effaced cisterna magna.

32:48

It clearly doesn't measure 10, uh,

32:51

you know, we're just not seeing it.

32:53

So that's a Chiari malformation.

32:54

So you want to look down in the

32:55

distal spine, and what do you see?

32:58

You see a, a spinal defect.

32:59

So this is a myelomeningocele.

33:03

Um, the next thing we want to look at is the cavum septi pellucidi.

33:07

Basically, you're looking for this. This

33:09

proves that the corpus callosum formed normally.

33:13

Um, so you're looking for mostly

33:15

agenesis of the corpus callosum.

33:17

If you're trying to di, if you're, um, trying to diagnose

33:20

holoprosencephaly, which is a very severe anomaly of the

33:24

brain based on an absent CSP, you're pro, you've probably got

33:28

other problems, because there's going to be a lot more going on.

33:31

But the subtle things, agenesis of the corpus callosum

33:34

and septo-optic dysplasia, um, are things you

33:38

would be able to see just by an absent cavum.

33:41

Now this might sound easy, but the cavum can be tricky.

33:46

And what you really want, you have to see these two things.

33:50

So it's going to be a box, and you want to see the frontal horns.

33:56

The lateral ventricles touching that box.

33:59

If you're not seeing that, you

34:01

have not diagnosed a normal cavum.

34:05

And I'll show you how it can be.

34:07

So look here, someone looks at this like, oh,

34:10

there's a little fluid-filled structure there.

34:11

I'm happy we got a cavum.

34:13

Well, the tech is doing their best to take some picture.

34:17

They're sort of inventing a cavum.

34:19

So you could see it's not a box; it's more of a triangle.

34:22

And if you really look here,

34:24

sorry, I've got to take my glasses off.

34:25

There's a frontal horn here.

34:28

It does not touch the side of this.

34:32

Here's another one.

34:33

You might look at this and be like, oh yeah, there's a

34:35

little, you know, fluid-filled structure right there.

34:37

Normal cavum.

34:38

Well, is it a box?

34:40

Maybe.

34:41

But look where the frontal horn is.

34:42

It's way out here.

34:45

And here's another frontal horn.

34:47

There's a kind of a triangular shape; it's not touching.

34:50

So really go back and make sure you see

34:52

a picture looking something like this.

34:55

Or send the tech back in to get it, or refer them on again.

35:02

Um, sometimes you'll see what the tech will try and call

35:07

a cavum, and there's a little line going through it.

35:10

That's actually the columns of the fornix, which is as,

35:13

as the, um, I'm going to go from the side view, as the,

35:17

um, uh, corpus callosum wraps around the bottom here.

35:22

You're actually cutting through below the CSP, so you

35:25

just want to make sure you don't call that also a CSP.

35:30

Now the lateral ventricle, this is the—

35:33

Um, uh, some of you may or may not know my

35:35

father was an obstetrical radiologist, did a lot of the

35:38

founding research in obstetrical sonography,

35:41

and he's called the lateral ventricle

35:43

God's gift to the radiologist, because almost every

35:47

clinically significant and detectable neurologic

35:50

abnormality will cause an abnormal lateral ventricle.

35:55

So it's really important to know how to see

35:57

this normally and know how to measure it.

36:01

So you want, you're looking at the

36:04

ventricle here, lateral ventricle.

36:06

The, the choroid, um, is filling the ventricle here.

36:10

So along the axis of the choroid, this

36:13

is how you want to make your measurement.

36:15

You don't want to measure from here to here,

36:17

for example, because that's overmeasuring it.

36:20

So you're measuring it as the choroid begins to turn here.

36:24

You're going to measure from here to

36:26

there, perpendicular to this axis.

36:29

Um.

36:30

Little tip.

36:31

If the choroid is filling the ventricle, it's normal.

36:34

There’s no way the ventricle is enlarged

36:36

if the choroid fills the whole thing. When you see the

36:40

quote dangling choroid, that's when you should probably

36:42

start thinking about making sure you measure it.

36:44

The tech's going to measure it every time, but

36:46

here you're measuring from here to here.

36:49

Um, I don't have what the measurement is.

36:51

It may be abnormal, it may be normal,

36:53

but 10 millimeters is a good cutoff here.

36:57

Here, it's really enlarged.

37:00

Sometimes people will get faked out, and they

37:03

actually don't get a good picture like this.

37:06

Here, this is actually—here's the

37:08

falx, here's the midline here.

37:09

Someone is thinking this, to this, is the ventricle, but

37:13

just remember gravity is always in effect, and the—

37:18

choroid would actually be falling all the way down to

37:21

here and laying here if this were actually the ventricle.

37:25

So sometimes you just have to make sure you

37:27

change your gain or whatnot and make sure

37:30

you're actually getting the full ventricle.

37:33

So now you can see the edge is actually here

37:36

and here. You know, this is always the bottom.

37:38

So you would measure from this

37:39

point to this point right there.

37:42

Greater than 10 is abnormal.

37:45

Less than 10 is normal.

37:47

If you're getting 9.9, 9.8, and you feel

37:51

a little uncomfortable, get a follow-up.

37:54

But don't start sending them off to, you know,

37:56

get, um, fetal MRIs and things like that.

38:00

Uh, choroid plexus cyst.

38:01

This is something we see all the time.

38:04

Um, there are several soft markers we'll talk about,

38:06

and these are soft markers for chromosomal abnormalities.

38:10

Um.

38:11

The, let's just say that these

38:14

aren't the, the greatest thing.

38:16

You want to identify them, but you

38:18

don't want to freak the mother out.

38:20

I'll, I'll go back to a story about my dad again.

38:22

The most pop, most read article he ever, um,

38:28

published was How to Scare a Pregnant Woman to Death.

38:31

And it was all about these soft markers.

38:33

So both, all three of my girls had, uh, choroid plexus cysts.

38:39

They're all lovely, intelligent young ladies.

38:42

So this is something that you do want to

38:44

comment on, but you don't want to get

38:47

people too worked up about it.

38:49

If the rest of the scan is normal and

38:51

their prenatal testing is normal, you can

38:54

generally, um, ignore these. If it's really big,

38:59

that's kind of concerning.

39:01

Um, you do want to document an open hand.

39:04

Um, trisomy 18 has this classic sort of clenched

39:07

fist, um, and all babies have a clenched fist.

39:11

This is actually the clenched fist of trisomy 18, actually

39:14

has an overlapping thumb and a little finger here.

39:18

So, again, I don't know if you can see

39:19

me, but it looks kind of like that.

39:23

Um, the fetal face, that's part of

39:26

the pictures that you want to take.

39:27

Why do we take that?

39:28

Obviously, the parents love to see a profile.

39:31

Um, the one thing you want to look for, if, when,

39:33

if you're taking this picture, is that there

39:36

is a nasal bone and it doesn't look really short.

39:39

A lot of times the techs will take a picture

39:40

off to the side and not include the nasal bone.

39:44

That can be kind of dangerous, because if you come

39:46

back later and, you know, let's say the baby did

39:48

have Down syndrome and you've got a picture showing no

39:50

nasal bone, even though it could have been normal.

39:53

It—

39:53

You just have to know that, that, um, you, you

39:56

just want to make sure that picture's there.

39:57

Also, you can take a picture off axis, and I've seen this

40:01

happen in a malpractice case where the chin was small.

40:05

Um, you know, you, you're looking for micrognathia.

40:08

You just want to make sure that you don't

40:10

take a picture that makes it look abnormal.

40:13

Make sure you take a picture that makes it look normal.

40:18

This is the other picture you take

40:20

from the, from the, for the face.

40:21

This is for cleft lip.

40:23

People struggle with this a little bit.

40:24

This is a coronal view of the face.

40:26

So again, I think you can see me on the video

40:28

here, but you're basically cutting through right

40:30

across a coronal view of the lips and nose.

40:34

So this is the nose, nostril, nostril,

40:37

upper lip, mouth, lower lip, and chin.

40:42

So if you kind of turn that on its side, you're

40:44

kind of looking straight onto the baby like

40:45

this: nostril, nostril, upper lip, lower lip.

40:48

And then here, this is a little cine clip.

40:52

Nose, upper lip with a cleft here, lower lip there,

40:59

and that's just that clip again.

41:02

Um, so that's mainly the one thing you're going to find.

41:05

So just make sure they take a normal-looking profile

41:09

and a normal-looking coronal view of the lips.

41:12

Um, we always image the spine, um, the cervical spine.

41:17

You'll almost never see any bony abnormalities.

41:19

You know, you might see a cystic hygroma in this area.

41:23

I use this picture mainly to look at the nuchal thickness.

41:26

Um, a nuchal thickness over six, uh, is

41:30

suspicious for Down syndrome, um, at 20 weeks.

41:34

Um, the reason I like to look here is because

41:38

sometimes, if you're looking at it here, it can be tricky.

41:40

This is the occipital bone, so you measure

41:42

from the occipital bone to the skin, but

41:45

sometimes the occipital bone gets shadowed out.

41:48

Sometimes you can make it look too big.

41:49

Sometimes you can, uh, not see it well.

41:52

So if you're struggling, again, this picture is

41:55

not required, but a lot of people will take it.

41:57

So if you're struggling here,

41:59

you can always look for it here.

42:00

Even if the tech didn't go and take this picture,

42:03

you'll usually see it on the cervical spine picture.

42:05

The thoracic spine.

42:08

Again, you're just going to make sure it—it's.

42:10

Uh, you're not going to see a lot of anomalies.

42:13

I mean, if you pick up some sort of subtle

42:14

vertebral anomaly, you're really doing a great job.

42:18

The money on the spine occurs down in the lumbar region.

42:22

Um, you really want to look at this, uh, sacral

42:26

upturn here and see that the skin is covering it.

42:33

Um, so here we see there's a big cystic lesion here.

42:38

And this, this—you don't see the sacral upturn

42:40

here, you don't see the bones going past this area.

42:44

You might see something big like a sacral teratoma as well.

42:49

Um, so, yeah, like I said, most of the

42:52

money is occurring down in the lumbar spine,

42:54

not up in the cervical or thoracic spine.

42:57

Um, I spend most of my time looking at the heart.

43:00

Um, I mean, I do spend time looking everywhere, but the

43:03

heart is the one that, you know, people miss things a lot.

43:06

Um, people used to just do a four-chamber view.

43:10

Um, the outflow tracts are

43:12

now included in the recommendation.

43:14

So make sure you're doing all of these.

43:16

If you're doing any fetal ultrasound, I add them: do a

43:20

four-chamber view, a four-chamber cine clip, the three-

43:23

vessel view, and the LVOT and RVOT, and I'll show you why.

43:27

Um, the four-chamber view is not just about counting

43:31

four chambers, which is easy enough to do, but make

43:34

sure there are four chambers on your four-chamber view.

43:36

I've seen plenty of techs take one with only three chambers,

43:40

but we're going to identify that there are four chambers.

43:42

We're going to look at the chamber size,

43:44

we're going to assess position and axis.

43:47

We can look at the valves, we can assess

43:50

situs and assess for chest masses.

43:53

So this view, one view, accomplishes a lot of stuff.

43:57

So the descending aorta is here. The chamber that should

44:02

touch it is the left atrium.

44:05

So if you know that's the left atrium, then you know that's

44:07

the left ventricle, that's the right ventricle, which

44:10

should be the most anterior, and that's the right atrium.

44:13

So spine, aorta, left atrium, left

44:16

ventricle, right ventricle, right atrium.

44:18

Easy to identify the chambers.

44:20

They should be about the same width.

44:23

If they're not, suggest a fetal echo.

44:28

The black blood in the left

44:31

ventricle should come all the way to the end.

44:34

If it doesn't, recommend a fetal echo.

44:40

Um, when you're assessing situs,

44:43

actually not included in this picture, but

44:45

you want to just make sure that the apex of the

44:47

heart here is on the same side as the stomach.

44:49

And we talked a little bit about situs earlier.

44:52

That's the most important thing,

44:54

because dextrocardia has a very

44:56

high association with anomalies.

44:57

Um, we're also going to assess heart position and axis.

45:02

So if you draw a line from the spine through the

45:06

sternum, the entire right atrium should

45:10

be on this side of the line, and it should cut

45:13

through the right ventricle and the left atrium.

45:16

And then if you draw a line through the

45:17

septum here, that should be about 45 degrees.

45:21

If you don't see that, suggest an echo

45:25

or suggest a level two ultrasound.

45:27

You're not, you may be dealing with

45:28

a chest mass or a cardiac anomaly.

45:31

So here, let's draw a line.

45:33

This is pretty obvious.

45:35

The entire heart is to the right of this line.

45:38

So you've got a big shift.

45:41

This happens to be a congenital diaphragmatic hernia.

45:44

Whether you knew that or not, it doesn't matter.

45:46

You identified that the heart is shifted to

45:48

one side, and you recommended another study.

45:52

This one's a little more subtle.

45:54

Here's the line going through the middle. We said that the

45:58

aorta should touch the left atrium, and it doesn't.

46:01

So that's clue number one.

46:03

This angle here is way less than 45 degrees.

46:07

Whether you identify this subtle, you know that there could

46:11

be another bowel-filled, I mean, or stomach down.

46:15

CDH doesn't matter.

46:18

You've identified that there's an abnormal cardiac

46:21

axis, and you've suggested another study

46:25

because this didn't satisfy the criteria, you know,

46:29

to be normal.

46:32

Um, like I said, I always do a cine clip of the heart.

46:38

Um, you want to look at these valves.

46:41

So remember spine, aorta, left atrium, left

46:46

ventricle, right ventricle, right atrium.

46:48

So tricuspid valve, I like to see two

46:51

leaflets there opening and closing. Here, I like to

46:54

see leaflets opening and closing separate from each other.

46:57

The reason being, on a pure static image, and even on this,

47:03

this is actually one giant monovalve opening and closing.

47:08

Here you see a valve and a valve, and if the tech takes

47:12

a picture with the monovalve open, this is an AV canal.

47:17

There's nothing that resembles

47:19

a normal four-chamber view here.

47:21

But if they took this picture, it kind of

47:23

almost looks like a normal four-chamber view.

47:25

If you measured your axis, it would be off.

47:28

This would be greater than 45 degrees,

47:30

by a long shot, almost 90 degrees.

47:32

So you might, if the tech took this

47:35

picture, identify it, or you should.

47:39

But you wouldn't notice.

47:43

You wouldn't know that there's a gaping

47:44

hole in the center of the heart here.

47:46

So that's why I always instruct them to take

47:48

cine clips and really just say, take five seconds.

47:52

Just, oh, I see valve leaflets here,

47:55

and I see valve leaflets there.

47:56

I'm done.

47:58

So, putting it all together, here's a heart.

48:02

Um, aorta.

48:04

Left atrium, right atrium, right

48:06

ventricle, left ventricle. Well,

48:08

are the chamber sizes the same?

48:10

Nope.

48:11

Does the blood in the left

48:13

ventricle go all the way to the end?

48:15

No, it actually comes farther here.

48:17

How does our axis look?

48:19

It's way off.

48:21

We've identified, through, you may have no

48:23

idea that this is a hypoplastic left heart.

48:26

That doesn't matter.

48:27

You've just, you've followed the

48:29

rules, and you know that it doesn't meet the

48:31

rules that you know you're supposed to have.

48:34

And so you're going to, um, you're gonna

48:38

refer this patient for a fetal echo.

48:41

Um, echogenic intracardiac focus is

48:44

another one of those soft markers.

48:46

Um, again, it's really common. As long as there's no

48:49

other abnormalities, it has an association with Down syndrome.

48:53

Um, you know, we, we can measure that nuchal thickness.

48:56

If it's normal and there's no other abnormalities,

48:59

you can generally put this, this is kind of the,

49:01

the consensus statement of what people decided to

49:04

say about it in the absence of other risk factors.

49:08

Nowadays, people are getting nuchal

49:09

translucency testing, first-trimester labs.

49:12

There's even fetal DNA screening.

49:15

So it's pretty easy to noninvasively

49:19

turn this patient into a low-risk patient.

49:23

Um, we're gonna get into the outflow tracts last here.

49:26

So the left ventricular outflow tract, all you

49:28

need to see is that the anterior wall of the

49:32

aorta lines up with the interventricular septum.

49:36

If you have that, it's normal.

49:39

Here's an example.

49:40

Anterior wall of the aorta does not line

49:43

up with the interventricular septum.

49:45

It's abnormal. Normal, abnormal.

49:50

You don't need to know.

49:51

It's an overriding aorta.

49:52

It doesn't matter.

49:53

You're gonna refer that person to a fetal

49:55

echo because it didn't satisfy your criteria.

49:59

If you're not referring people for fetal echoes,

50:01

you're probably not sending enough people out,

50:04

because you need to, you know, you want to have

50:08

some people coming back with normal echoes.

50:11

Uh, right ventricular outflow tract.

50:12

This is, um, it's, uh, just the anterior wall.

50:16

It's nice to see this in a sagittal plane.

50:19

You should just see this kind

50:20

of looping up and in the fetus.

50:23

It's kind of going into the, um, what is

50:26

going into the aorta through the ductus.

50:28

And this is actually one of the best pictures we'll see.

50:31

So this is called the three-vessel view.

50:33

So this is the pulmonary artery, or pulmonary

50:37

outflow tract, going into the, um, right here.

50:40

It's going into the ductus arteriosus and into the aorta.

50:44

Then we have the aorta.

50:46

The superior vena cava.

50:47

So it's, some people call it the dot-dash view,

50:50

but a lot of people call it the three-vessel view.

50:52

And it's basically, if you're used to looking at CTs of

50:55

the chest, you can see here the baby has a patent ductus.

51:01

So it's going from the pulmonary artery to the

51:04

aorta here, the descending aorta. Here's

51:07

the ascending aorta, and here's the vena cava.

51:10

So it's basically that picture.

51:13

And the problem is, you know, in fetuses,

51:16

it's sort of rotated in different ways.

51:19

Um, but this vessel should, usually,

51:23

these should be about the same size, or

51:25

if one's going to be bigger, it's going to be this.

51:28

And again, do you need to

51:30

know how to diagnose, um, transposition?

51:33

No, but you're going to look at this

51:37

image here, the three-vessel view.

51:40

And do you see the—

51:44

You see, uh, basically this structure, the

51:48

ductus. The aorta is way up here, and the SVC is here.

51:54

Remember, in this one it should be getting progressively

51:57

posterior, anterior, a little more posterior, a little

52:00

more posterior, anterior, a little more posterior.

52:04

A little more posterior.

52:05

Here it's anterior, more anterior, way posterior.

52:09

So again, you don't need to know that this is transposition.

52:13

You just need to know that the

52:14

three-vessel view is abnormal.

52:16

So the things you want to know: identify the chamber size,

52:21

valve leaflets, shift, axis. Does the anterior wall, the

52:27

LVOT line up with the interventricular septum, and

52:31

make sure that the three-vessel view is normal.

52:32

I didn't actually include in here that the blood in

52:35

the left ventricle goes all the way to the tip.

52:39

So those nine steps.

52:41

It sounds like a lot of steps, but it's really,

52:44

you, your, if you do this at, at any amount, you

52:47

can literally do this in a matter of seconds.

52:49

Just like you kind of look at a, a

52:51

liver on a CT scan and it looks normal.

52:53

You, you don't, you know, go and look at

52:55

every pixel on there. Um, the stomach.

52:59

You wanna make sure it's present and not enlarged or absent.

53:04

Um, if it's absent, you're thinking

53:06

about things like esophageal atresia.

53:08

Usually it's just empty,

53:09

and the mother, you know, the baby's not drinking, and if

53:12

you brought them back a little later, it would look fine.

53:15

Um, and you also wanna make sure if you see.

53:20

Polyhydramnios, a distended stomach, you might see a

53:23

double bubble or think of a distal atresia.

53:27

So if you see other dilated loops, this is the

53:29

double bubble: dilated stomach, dilated duodenum.

53:32

That's highly suspicious for Down syndrome.

53:35

The kidneys, you're basically

53:36

wanna make sure they're present.

53:38

The most common thing we'll see is some mild ectasis.

53:41

Um, you know, renal agenesis, multicystic dysplastic.

53:45

I'll show you some pictures of those.

53:47

But you know, you're not running into that hydronephrosis,

53:50

big bladder, multicystic dysplastic kidneys.

53:55

You're just not gonna see these.

53:57

Um, this is the one I see people actually miss.

54:01

Um, the tech.

54:02

What, what you notice here is

54:03

that there's zero amniotic fluid.

54:06

That's the key.

54:07

At that point, it's gonna be hard to see

54:09

whether the kidneys are present or not present.

54:12

What you wanna identify is the

54:13

fact that there's no fluid here.

54:15

And I've seen people miss this, and the tech just kind of

54:18

took a picture of the kidneys are hard to see as it is.

54:20

So they said, oh yeah, there's a kidney there.

54:23

I'm not gonna go into the lying-down adrenal sign.

54:25

But the point is, you're gonna identify renal abnormalities

54:30

oftentimes, if they're severe, by the lack of fluid.

54:34

Um, pelvic ectasis is the main thing, is that it can progress.

54:39

So if you see the renal pelvis is greater

54:41

than four millimeters at 20 weeks,

54:43

it's another one of those soft markers.

54:45

So you wanna make sure there's no other

54:46

abnormalities and kind of mention it.

54:47

But it's like the echogenic cardiac

54:49

focus and the choroid plexus cyst.

54:51

It's not really that high of a risk.

54:54

Um, and you wanna follow up at 32 weeks for progression.

54:58

The cord insertion, we're looking

55:00

for gastroschisis, um, omphaloceles.

55:03

That's what a gastroschisis looks like.

55:05

Again, I don't need you to know this.

55:07

This is an omphalocele.

55:09

The main thing is echogenic bowel.

55:12

When you're looking at that

55:12

area, you're gonna see the bowel.

55:15

People call echogenic bowel all the time.

55:17

We now have these really high-frequency

55:20

transducers, and they can make the bowel look echogenic.

55:24

So you wanna call it if it's as bright as the

55:26

bowel, and you wanna back off to some lower megahertz

55:29

transducers, make sure you're not getting faked out.

55:32

And the last most important thing is the bladder shot.

55:36

And that's because that's where the, the cord goes.

55:39

Um, or the, where we identify a two- or three-vessel

55:43

cord. If you only see one vessel here, that's

55:47

a two-vessel cord or a single umbilical artery.

55:49

And that, in and of itself, isn't that big of a deal.

55:53

You know, it's not an actual anomaly, but it's

55:56

associated with so many other anomalies that if you

55:59

see it, you wanna refer them off for an, uh, level two

56:03

ultrasound because it's associated with other things.

56:06

And what you'll see a lot of times

56:08

is that's the one thing people miss.

56:10

Um, you don't wanna, you wanna make sure that the

56:13

vessels you see are touching the bladder on both sides.

56:16

'Cause the iliac artery and femoral

56:18

artery can simulate a second vessel there.

56:22

Uh, lower extremities, we're looking

56:23

for clubfoot, clubfeet, sorry.

56:26

You wanna just make sure the arms and hands and

56:28

feet are present.

56:31

You don't wanna miss, uh, an, an absent, um, limb.

56:36

Um, so I just usually just take a picture of the

56:38

feet and hands and make sure there's no clubfoot.

56:41

Um, and you're gonna finish with some assessment,

56:44

you know, size is consistent with dates or

56:46

there's normal growth or something like that.

56:48

And that'll be your impression.

56:49

And I know that was super fast through, but hopefully

56:52

I gave you some ideas on how to stay outta trouble

56:55

with, um, dictating these and interpreting them.

56:58

And so we wanna go into some questions.

57:01

I'm happy to do that.

57:02

I don't know exactly how to do that.

57:04

Yep, that would be great.

57:05

So there's a Q&A button that

57:07

should be at the top near your icon.

57:09

Okay.

57:10

And then if you open that up, I do see

57:11

a couple questions in there for you.

57:13

Okay.

57:14

So looking at centile values of parameter, a better

57:17

indicator of IUGR or difference in weeks good enough?

57:20

No, the difference in weeks is what's going to

57:23

make you sort of look down to see what the percentile is.

57:29

But the percentile is what diagnoses IUGR. Less than

57:33

10th percentile is IUGR. Greater than 90th is, you

57:37

know, large for gestational age or macrosomia.

57:40

So you don't wanna call IUGR unless,

57:42

unless you're less than the 10th percentile.

57:46

Do you have a specific thickness to call the membrane thick?

57:49

No, thick thickness.

57:51

Like the thin membrane is literally like pencil-thin.

57:55

Um, the thick membrane, it's a visual thing.

58:00

There's not a measurement.

58:03

Um, can we diagnose hydrops accurately

58:05

in the second or third trimester?

58:08

Absolutely.

58:09

Hydrops.

58:10

I didn't get into it, it's a big, um, uh, it's a big, huge

58:17

differential, but you're looking for thick skin, poly,

58:23

pericardial effusions, pleural effusions, things like that.

58:27

So you can, that fetus will

58:31

look very, very, very abnormal.

58:35

Uh, can you explain cardiac axis once again?

58:40

Sure.

58:47

Um,

58:49

So again, you wanna draw a line from the spine

58:54

through the sternum.

58:55

Sometimes you can't actually see the sternum,

58:57

uh, but you know it's gonna be somewhere mid

58:59

chest, and then you will draw a line from there

59:04

down the interventricular septum like that.

59:07

And that angle should be about 45 degrees.

59:10

It could be a little less or a little more, but

59:14

if it's anything, you know, considerably off, you

59:17

know, down in this area or down in this area, you

59:21

should be, um, calling it abnormal axis.

59:25

And again, refer them on.

59:27

It doesn't matter whether you're right

59:29

or wrong, um, it's okay to be wrong.

59:33

Um, you might scare the mom somewhat,

59:36

but you know, it is what it is.

59:37

You, you wanna make sure you're not missing

59:39

something bad if you find an absent CSP.

59:44

How do you conclude?

59:47

Um, I assume that means like, what would my impression be?

59:49

I would just say there's an absent cavum septi pellucidi.

59:53

Or I'm not seeing it, recommend, um,

59:57

fetal, um, you know, recommend perinatology

60:01

or maternal-fetal medicine evaluation.

60:03

Just, just leave it at that.

60:05

I mean, if you wanna get fancy and you could

60:07

say, you know, this can be seen in the setting

60:10

of, um, uh, agenesis of the corpus callosum.

60:15

You could recommend a fetal MRI.

60:17

It depends on how comfortable you are.

60:18

But if you're at a baseline level, just recommend a more

60:23

detailed sonogram that's being performed by a specialist.

60:28

How to troubleshoot when it's hard

60:29

to get abdominal circumference.

60:31

Um, that's going back to what I talked about,

60:35

that roundness makes up for a multitude of sins.

60:38

If you can get it to be round, you're probably

60:42

on a pretty good, um, you're probably in a

60:46

pretty good estimation of where it lives.

60:49

And you know what, if you are having trouble and

60:51

you're overmeasuring it, just know that let's say the

60:55

baby's measuring small and you've overmeasured the

60:59

abdominal circumference, you now know that even though

61:02

it's measuring small, it's actually even smaller.

61:05

And sometimes you can put that, you could say, you know,

61:08

we had trouble getting the abdominal circumference due

61:10

to the fetus's obliquity, and it was overmeasured.

61:14

The baby's measuring, you know, one week less than dates.

61:18

So this may actually be, you know, even overestimating

61:21

the size, and the baby may be measuring even smaller.

61:25

Hopefully that answered your question.

61:28

Uh, placenta previa and abnormalities

61:30

I may have missed in the beginning.

61:32

Yeah, we did cover that pretty extensively for a while.

61:36

Um, I don't know if I need to go back

61:38

through two vessels touching bladder.

61:42

Um, maybe you just wanna see that again.

61:50

So notice here it's coming in.

61:52

Both sides are touching the urinary

61:55

bladder here on either side.

61:57

That's normal out here.

62:00

This one's touching the side.

62:01

There's nothing touching this side from the anterior.

62:04

This is kind of looking like it's touching it

62:06

because it's on the backside, but this is the

62:08

iliac artery going into the femoral artery there.

62:12

So you wanna definitely make sure you see

62:14

both vessels touching anteriorly here.

62:18

Uh, I often find the femur length is discrepant.

62:20

Yes, that is true.

62:21

So I'm, I'm read it.

62:22

I often find the femur length is discrepant

62:24

relative to other biometric measurements.

62:26

Do you find this or is it software-dependent?

62:28

No, that's really common.

62:31

And why is that?

62:32

Because there are short people out there.

62:36

Um, so the biometry is basically like you're looking at

62:39

someone going, like, you know, imagine looking at a person

62:41

in, in real life and you're like, ooh, they have a big

62:44

head, they have a big belly, but their legs are short.

62:47

You know, they, they, babies are just the same way.

62:50

So what you really, when you run into that, what

62:55

you should have eventually, you know, if you're

62:58

doing this enough, you'll have a pretty good sense

63:02

of what normal fetal bone morphology looks like.

63:09

And what I say is, um, you know, the

63:13

fe, the femur is measuring short.

63:15

However, the morphology looks normal.

63:19

Um, you know, this may be due to

63:21

short stature or something like that.

63:24

So, so to answer your question, yes, that's super common.

63:28

Uh, measuring abdominal circumference,

63:30

should stomach be included in the view?

63:32

Yes.

63:33

It should axial view, right?

63:35

Yes.

63:36

It's, it's might be an, it's could be an

63:38

oblique axial, but yes, it's basically axial.

63:43

How to differentiate between IUGR and small

63:47

for dates, it's the percentile.

63:49

Less than 10th percentile is IUGR.

63:53

Um, 12th percentile is small for dates.

63:56

Um, you know, again, you also are gonna

63:59

comment on, so my impression, let's say fetus

64:02

is measuring eight days less than dates.

64:05

Um, the fetal weight percentile or the fetal weight

64:09

falls in the 31st percentile suggests follow-up to

64:12

assess for developing intrauterine growth restriction.

64:15

That's what I would say as my impression there.

64:20

What timeline do you suggest for bringing

64:21

patient back for incomplete scan?

64:23

It kind of depends on the reason.

64:25

If someone sends you a baby at 18

64:29

weeks, uh, I'd bring them back at 20.

64:32

If they send it to you at 20 and it was incomplete because

64:36

the spine was up the whole time and you couldn't see the

64:38

heart, I mean, you could bring 'em back later in the day

64:41

or the next day, um, because the baby's going to flip over.

64:44

So it depends on if you're waiting for them to get

64:47

bigger or you're waiting for them to change position.

64:50

Uh, hopefully that answers that question.

64:53

Uh, echogenic bowel, please repeat.

65:00

Um, so echogenic bowel, um, what I was saying was, you

65:05

know, nowadays everyone's got these, you know, really

65:09

high, um, megahertz transducers, eight megahertz, 10

65:15

megahertz, and they're getting these amazing, gorgeous

65:18

pictures, but it can really make the bowel look echogenic.

65:23

So first off, the rule is the bowel

65:27

has to be as echogenic as the bone.

65:29

So you might look like the bowel adjacent

65:31

to the iliac wing or something like that.

65:33

If it's not as echogenic as the bone,

65:35

it's not echogenic. Let's say it is.

65:38

Then you wanna say like, you know, this is a long time ago.

65:41

Actually, this is back from UCSF, and I can

65:44

tell you this machine was an older machine.

65:46

This is an eight curved transducer,

65:49

um, at scanning at eight megahertz.

65:52

So it made, it made the bowel look really echogenic.

65:55

When we changed, when we took our, our, um,

65:58

megahertz down to four and took off harmonics,

66:03

you, you're actually, now the bowel looks totally normal.

66:07

So that's kind of what I was saying.

66:09

So you wanna take off all these things that are there on

66:12

these machines now to make these gorgeous pictures, but they

66:15

can cause the bowel to look echogenic when it's really not.

66:19

Hopefully that, um, answered that. Placenta accreta.

66:23

Do we need MRI, and why?

66:25

Um, we didn't go too deep into placenta accreta

66:28

because I, it, it is kind of hard to diagnose.

66:31

Um, the big takeaway I wanted you to know was

66:36

that if you, is how to refer it to someone else.

66:41

Um, and, and, uh, you know, if you see a low-lying

66:45

placenta and the patient has a history of previous cesarean

66:50

section, then you want to, you know, make sure that you

66:55

have somebody go look for an accreta,

66:59

even if it's not going to be you.

67:01

And I'll show you why this is tricky.

67:07

So let's look at this picture right here.

67:10

How thin is, here's the placenta, here's the bladder.

67:15

I mean, this looks pretty darn thin.

67:17

So trying to measure it is tricky.

67:20

What you wanna look for is a lot of flow in

67:24

between the placenta and the bladder wall.

67:27

Um, you might see some cystic change in the placenta.

67:31

The question was, do you need MRI?

67:34

I've, I haven't done a ton of MRI for it.

67:36

I know people use that.

67:38

When I have done an MRI, it honestly didn't really help.

67:41

It sort of is like this again.

67:44

Maybe you could see more of that

67:45

cystic change in the placenta.

67:47

You know, I don't think, uh, it's, it's required,

67:51

but it is such a dangerous thing that any

67:54

additional information is not going to be unhelpful.

68:00

What are the differentials when

68:01

the bowel is truly echogenic?

68:03

Um, it could be something as simple as, um, uh, there,

68:09

there was some, some hemorrhage and the baby swallowed

68:13

some blood products that can make it echogenic.

68:15

The big thing people talk about is it being

68:18

another soft marker for chromosomal abnormalities.

68:21

So we talked about echogenic intracardiac focus,

68:24

bilateral fetal renal ectasis, and choroid plexus.

68:28

Those are soft markers.

68:31

Nuchal thickness enlargement and

68:33

echogenic bowel are also soft markers.

68:36

And what a soft marker means is that

68:38

it's not an actual anomaly, like

68:41

having a thick nuchal fold isn't like something that's going to

68:44

cause you a problem later in your life, like a heart defect.

68:46

So it's a soft marker that's associated with anomalies,

68:52

but echogenic bowel and nuchal thickening, nuchal thickening

68:56

are much harder soft markers, if that makes sense.

69:00

Um, and then you can also see it with things

69:02

like cystic fibrosis, um, or fetal infection.

69:05

That's, those are, if you know that kind

69:08

of differential, that's probably enough.

69:12

Where can we use harmonic ultrasound and fetal imaging?

69:16

Um, I assume you mean harmonics.

69:18

I use it everywhere, anytime I can.

69:22

Um, whatever you can do to make your pictures better.

69:24

You want to try and turn it off if you

69:27

think you're dealing with echogenic bowel,

69:29

because it can make the bowel look more echogenic.

69:31

Hopefully that was what you were asking.

69:34

Can placenta accreta be diagnosed on

69:36

a one-time third trimester scan?

69:38

Sure, it can.

69:40

Um, you can diagnose it.

69:43

Yeah.

69:43

Anytime.

69:45

Um, different radiologic criteria for

69:47

IUGR, I just use less than the 10th percentile.

69:51

Um, that's, that, that's an easy,

69:55

and that's pretty much the diagnosis.

69:56

Because really you're dealing with, you

69:58

know, it's, it's the extremes of growth.

70:00

Less than 10th percentile, greater than 90th percentile.

70:03

That's what these are indications for.

70:07

Transvaginal ultrasound, um, like I

70:09

said, very, I have a very low threshold.

70:12

Anytime I'm looking at something that might

70:15

look like a short cervix or something that might

70:19

look like a previa, I will have, I just have

70:21

a very low threshold for looking vaginally.

70:25

Um, should I change the settings for

70:28

measurements according to ethnicity?

70:31

Um, not, I, we do not, I have not heard of doing that.

70:37

Um, so I, I, my, my answer would be no.

70:41

That would be a nightmare to try and do that every time

70:44

you, you know, are doing a scan on different ethnicity.

70:49

And I think that finished up all the questions.

70:52

Yep, I think so.

70:53

So as to bring this to close, I just wanted

70:54

to thank you, Dr. Philly, for your time today.

70:55

And thanks to all of you for

70:56

participating in this noon conference.

70:58

A reminder that it will be made available

70:59

on demand, complimentary@mmrionline.com .

71:02

In case you missed anything or wanted to go back

71:04

and review part of this, and Tam, please join us

71:06

for a noon conference on ankle tendons, an update.

71:09

Thank you, and have a wonderful day.