0:01

So generally, the patient's going to

0:03

be placed supine on the table when

0:04

you're doing a transabdominal view.

0:06

Again, you're going to fill that bladder as much

0:08

as possible to get rid of the bowel gas, pushing

0:10

that up and out of your image field of view.

0:13

And generally, you're going to

0:13

use the five curve as your general

0:15

probe for transabdominal imaging.

0:18

The transvaginal probe, however,

0:19

is a high-frequency probe.

0:21

That means you're going to get high

0:22

resolution imaging, very beautiful pictures.

0:24

But, because the frequency is high, those

0:26

ultrasound waves are not going to go very

0:28

far before they get lost to form the image.

0:31

Therefore, you have a limited

0:32

distance of what you can view.

0:34

However, we don't image

0:35

patients in an upright position.

0:37

Generally, we're going to see

0:38

them as supine, as we do here.

0:41

So that transabdominal view, again, you're

0:43

going to put that probe directly onto

0:45

their anterior pelvis right here, and

0:47

use the bladder as a window to visualize

0:49

the cervix and the uterus itself.

0:51

That's going to create an

0:52

image that looks like this.

0:54

So here is your five curve

0:56

probe will be up here.

0:57

This is going to be your skin subcutaneous

0:59

fat, soft tissue, some musculature.

1:02

Then you have your anechoic bladder right

1:04

here, which is nicely distended, creating a

1:05

beautiful window so that you can see the uterus.

1:08

We have the vagina down here.

1:10

The cervix is right around here, lower uterine

1:12

segment right around here, in the body of

1:14

the uterus, and here the fundus is a little

1:16

bit obscured due to bowel gas that didn't

1:18

quite get pushed out of the way here.

1:20

You also have some of the endometrial

1:22

contents right here, and a little

1:23

bit of free fluid in the cul-de-sac.

1:27

Of our transvaginal, you have

1:28

a limited field of view here.

1:30

Again, we talked about the high-frequency waves.

1:32

You're going to get beautiful imaging,

1:34

high spatial resolution, but it's not going

1:36

to go very far, the waves as they travel

1:38

before they get lost to form that image.

1:41

You're also limited by a fixed plane of imaging.

1:43

As we mentioned before, you can see in this

1:45

example here, the ultrasound waves may be

1:46

sending waves in these different directions,

1:49

but it's not necessarily going to capture

1:50

all of the uterus in a single plane right

1:53

here due to that limited field of view.

1:55

That's always important to remember when

1:57

you're measuring a structure, particularly

1:58

the uterus, you may not get it in one

2:00

field of view, so your imaging may not

2:02

be perfectly accurate when you're looking

2:04

for length of different structures.

2:08

Another thing to remember when you're doing

2:09

transvaginal imaging is now you want the

2:11

bladder to be decompressed, so that the patient’s

2:13

going to need to empty their bladder.

2:15

And that's for two reasons.

2:16

Number one is patient comfort.

2:18

It's really uncomfortable to have a transvaginal

2:20

probe there and to have a full bladder.

2:22

Number two is if this bladder is overly

2:24

distended, you can imagine it's going

2:25

to push the top of the uterus back.

2:27

And if it gets too far in a sort of upright

2:30

position, it may actually be too far

2:32

to get good images of it because remember,

2:34

high-frequency probe, you need short

2:36

distances to get those beautiful images.

2:38

So two things there to keep in mind.

2:40

So with that all being said, are we

2:42

ready to look at some ultrasounds?

2:46

Okay, so this is an image from a sagittal uterus.

2:51

This is labeled right to left,

2:52

so I took this from a cine clip.

2:53

But just to give you an idea of

2:54

what we're looking at, this is

2:55

your transvaginal probe right here.

2:58

It's much more curved than the other

3:00

one was, a sharper curve there.

3:01

You can also see in the corner

3:02

right here that it's a 9.

3:04

That's a much higher frequency than your general

3:06

5 curve that you're going to be using.

3:08

So this is going to be in

3:10

the fornix of the vagina.

3:12

You don't really see the vagina here,

3:13

again, because the probe is within it.

3:15

So what you're seeing here

3:16

is what is up against it.

3:18

So in this particular image, we don't

3:19

really see the cervix that well.

3:21

Again, there might be a bend to the

3:22

uterus, which doesn't allow you to

3:23

see it perfectly in one single plane.

3:26

But here is the anterior part of the uterus.

3:28

So lower uterine segment, body, fundus

3:31

coming around here, and then posteriorly.

3:34

Uterine body, lower uterine segment, and

3:36

then we get down to the cervix down here.

3:38

Back here is going to be the rectum.

3:39

You might also have some mesenteric fat.

3:41

You might have some bowel loops nearby,

3:43

depending on what's there on that given day.

3:45

More centrally, you're going

3:46

to have the endometrial lining.

3:48

Which will vary depending on

3:50

the stage of the menstrual cycle.

3:51

And then oftentimes you can see the

3:53

arcuate arteries of the uterus kind of

3:54

going all the way around right here,

3:57

especially if you put on color Doppler.

3:59

Here it's important to remember

4:00

that the size of the uterus varies

4:02

depending on the age of the patient.

4:04

When they're pediatric, it's going to be small

4:06

and it's going to grow to reproductive age

4:08

about 8 to 9 centimeters in length.

4:10

It may be larger if the

4:13

rather than nulliparous woman.

4:15

So more kids, you may have a

4:16

larger uterus just in general.

4:18

It then starts to decrease in

4:20

size in the postmenopausal status.

4:22

And then it depends on how

4:23

far postmenopausal you are.

4:25

It can get down to three and

4:25

a half centimeters in length.

4:27

If you're very remote from your menopause onset.

4:31

And then, of course, endometrium is going

4:32

to vary depending on the stage of the

4:34

cycle in the reproductively aged woman.

4:36

And we'll go over some of those in a little bit.