0:01

Okay, so here is a case of a

0:03

patient with bilateral teratomas.

0:05

So again, for my female pelvis MR

0:08

cases, I tend to start with the

0:10

sagittal just to get a lay of the land.

0:12

So I know the uterus is anteverted.

0:14

I take a quick look at the

0:15

junctional zone and the endometrium.

0:18

You can see there are a few

0:19

cervical nabothian cysts.

0:21

Typically, we ask our patients to

0:22

empty their bladder prior to the study,

0:25

just so that there's no peristalsis

0:27

from bladder filling or overfilling.

0:29

Unless we're imaging the bladder or the urethra,

0:32

those would really be the main situations

0:35

where we would ask the bladder to remain full.

0:37

But otherwise, I find that with a full

0:39

bladder, it tends to displace the uterus

0:42

sometimes, and then as the bladder gets

0:44

overfull, it peristalsis and causes some

0:47

degradation of, of diagnostic quality.

0:50

Okay, so again, a quick overview, anterior,

0:53

middle, and posterior compartments, and

0:54

right away in the posterior compartment,

0:56

you can see there's an abnormal structure

0:59

there, and maybe another structure.

1:01

Okay, so now we look for the

1:03

ovaries, so that's the second step.

1:05

So these are my Small field of view,

1:08

T2 weighted images on the bottom

1:10

left that I'm scrolling through now.

1:12

So, Normally the ovary would be right

1:15

around here and you can see that

1:16

there's an enlarged structure here

1:18

and a similar finding on the right side.

1:21

So we're seeing a few little follicles,

1:22

but then we're seeing these abnormal

1:24

mass-like structures as well.

1:26

So now the next question is: what are these?

1:28

So we know that they have high T2 signal

1:31

within them, and then some debris or layering

1:34

material. This T2-weighted sequence

1:37

has been acquired without fat saturation.

1:39

So you can see the subcutaneous fat and

1:42

the fat within the pelvis is quite bright.

1:44

Now we're applying fat saturation, and

1:48

we've acquired a T1-weighted sequence with

1:50

fat saturation on the bottom right here.

1:53

So now we can see that these

1:55

areas that were bright without fat

1:57

saturation have now suppressed.

1:59

So there's clearly fat within

2:01

this lesion, and there is some

2:05

layering material that's sort of bright signal

2:07

on T1 and intermediate signal on T2, which

2:10

might represent some proteinaceous material

2:12

or maybe some liquefied fat, potentially.

2:15

And then in the right ovary, again, we're

2:17

seeing fat saturation within that area that

2:21

was high T2 signal without fat saturation.

2:25

And you can see that this patient

2:26

has some rounded or lobulated looking

2:29

structures within one component and

2:31

maybe another component as well.

2:33

So we would want to know if those enhance

2:36

to determine whether there are areas

2:38

of potential malignant transformation.

2:41

So the other feature that I talked

2:43

about briefly was in the last slide,

2:46

was that we have a free clue here.

2:49

So if we look carefully on the T2

2:51

images, we can see that there are some

2:55

alternating lines of bright and dark signal.

2:59

And that's what chemical shift looks like.

3:01

So right away, even without looking

3:03

at the fat-saturated sequences, we can

3:05

see this onion skin pattern.

3:08

And that tells us that there's

3:09

chemical shift within this lesion.

3:11

So it has to contain fat.

3:13

So you can look really smart at

3:14

your boards or, you know, at rounds.

3:17

If you say, "Well, I don't need

3:18

the fat-saturated sequences.

3:19

I can just look at the T2

3:21

and look for chemical shift."

3:22

And then you can impress your colleagues

3:24

or your faculty by knowing that little tidbit of information.