0:00

Okay, so this is actually a set of two patients.

0:03

So let me just load up.

0:06

This is patient number one here.

0:08

And you can see this is a bit of an older scanner and the

0:11

rest of lumen is not completely distended.

0:14

So there's a bit of collapse here, but here's

0:17

the tumor.

0:18

Outlining with my pointer here. And then on

0:21

the coronal oblique image you can

0:24

again see the tumor predominantly arises from

0:27

the right rectal wall and then I'll show you the axial

0:31

oblique image.

0:34

Which is this one here?

0:39

Okay, so I'll scroll through those images for you and I want

0:42

you to take a look at the soft tissues surrounding

0:45

the rectal Lumen. Is there

0:48

anything that catches your eye that may be of concern for

0:51

staging and specifically I'm talking

0:54

about and staging so just a bit

0:57

of a review for end staging right now. So one of

1:01

the criteria that is commonly in use is

1:04

the Dutch criteria and as you know staging and

1:07

staging for Radiologists on rectal

1:10

MRI is very challenging. And the reason for that

1:13

is there's a high false false

1:16

positive rate because small lymph

1:19

nodes can be positive and if we rely on

1:22

size alone, we can really over call

1:25

these lymph nodes. So some of the criteria that we're using

1:28

now in campus three different features.

1:31

So one is the size of the node. The other is

1:34

the signal intensity inside the node and

1:37

that's the third criteria is

1:39

the shape of the node so

1:42

The nodes that we consider to be normal are

1:45

those that are nine millimeters or more in short axis. If

1:48

they have a round shape that's kind of suspicious indistinct

1:51

margins and heterogeneous signal intensity

1:54

internally. So that's what's called The Dutch criteria

1:57

and the society the Society of abdominal

2:00

Radiology has some really good information on their webpage about

2:03

end-staging and Reporting. So

2:06

I would encourage you to look that up. If you have more questions about

2:09

that in this case, I

2:12

want to show you how I will actually

2:15

stage patients for end staging.

2:18

So let's put up the first question here.

2:21

So I've shown you coronal axial and

2:24

sagittal images in this patient and this

2:27

is biopsy proven rectal cancer. So

2:30

the first question is, what's the T stage this patient?

2:38

So I put together team one and T2 and then

2:41

the early versus late t3s and then

2:44

a T4.

2:45

So what do you think the T stage would be in this case?

2:50

And I'll scroll through the axial Bleak again.

2:53

And this is a bit of a challenging one because the rectal

2:56

movement is not really distended. So the walls

2:59

are kind of opposed on one another. So if

3:02

you're finding this challenging you're not alone.

3:05

So don't worry about that.

3:08

Okay, so let's see what people thought. Yeah, so a bit

3:11

of a mixed bag. So T1 versus T2 half and

3:14

then the other half top thought T3 release

3:17

date so nobody really thought this was in advance tumor

3:20

and that's that's true. So again, this is

3:23

quite a challenging one.

3:25

And I think it's just because of the curvature of

3:28

the tumor in the rectal Lumen. So what's going

3:31

on here is the left wall of the tumor. Sorry,

3:34

the left wall of the rectum is actually kind

3:37

of stuck on to the tumor. It's not involved by

3:40

the tumor. This tumor itself is really only

3:43

involving the right wall. It's sort of causing this curvature

3:46

and Distortion of the wall, and then the left wall

3:49

is just sitting on top of it. So that's what's causing that appearance. So

3:52

we're really looking for whether or

3:55

not and let me just exit this

3:58

go into single view so I can show you series that

4:01

I want. So here we go. So we're really

4:04

looking to see if the muscularis propria has been

4:07

maintained if you take a pencil or a pen and you're able to

4:10

trace the Integrity of the muscular

4:13

appropriate without any Interruption, that's a pretty

4:16

good sign that it's intact. So this was actually a T2 lesion.

4:20

And now let's talk about the end stage. So

4:23

just for reference. Let me

4:26

see if I can show you.

4:27

Yeah, so let's just scroll through these images and see

4:30

if anything catches your eye and then we'll come back

4:33

and talk about.

4:34

The answer for this question. So let's set up the

4:37

next question. What's the end stage for this patient?

4:42

So I know you can't measure so I'll tell you that.

4:46

This structure here has a diameter of

4:49

seven millimeters.

4:53

to anything that end stages

4:56

and we have all the end stages there.

5:00

on the multiple choice question

5:06

Okay, so, let's see what everyone thought.

5:09

Okay. Yes, so you are correct. So this is an N1 lesion

5:12

and this is

5:15

the most suspicious lymph node here. So if I

5:19

just show you a couple of other lymph nodes in this patient. So this

5:22

one here is a tiny little normal lymph node,

5:25

and you can see how small that is. Here's a couple of other little

5:28

tiny lymph nodes and then very this is

5:31

very variable Patient to Patient. So some patients will

5:34

have larger lymph nodes that are normal other patients

5:37

will have very tiny lymph nodes. The reason this one was

5:40

called as abnormal is just because of the spherical shape the intermediate

5:44

size and the fact that it stood out

5:47

more than the other nodes. So the margin looks fairly smooth, but

5:50

there was enough there that made us think

5:53

okay. This looks suspicious. So we call this a T2

5:56

and one Lucian and I'm going to

5:59

show you now the second patient so we can compare and

6:02

contrast what's going on in these cases. So here's

6:05

patient too. So this patient has

6:10

A much different appearance than the first patient that we

6:13

that we saw.

6:15

and there's a reason why I'm showing you the impact to back

6:18

so

6:20

So first, I'll show you where the tumor is. So there's this

6:23

there's the tumor for the second patients.

6:26

Okay, and there it is on the sagittal and I'm going to ask you

6:29

the same questions again, the two stage and the end

6:32

stage. So just focus on that as we're scrolling through and if you

6:35

see anything else that catches your eye, you know,

6:38

just keep that at the back of your mind and we'll discuss that but focus

6:41

on the T stage and the end stage. So

6:44

here's the sagittal T2.

6:47

coronal teaching oblique

6:50

and then just keep an eye out for what you think might

6:53

be normal versus abnormal lymph nodes and

6:56

then I'll show you a couple of other series as well.

7:00

So here's the axial oblique. There's the tumor

7:03

there.

7:04

So think about what you would call the T

7:07

stage in this case.

7:09

And then on the other side, I'm going to put up the full

7:12

field of new axial to you. So we'll scroll through each of

7:15

those.

7:16

separately

7:19

And while we're just doing that I'll just

7:22

go over Regional versus distant lymph

7:25

nodes. So the ajcc can

7:28

find local Regional involvement to everything that's

7:31

in the meso rectum. So everything inside here

7:34

is considered local Regional disease including

7:37

the inferior rectal and

7:40

the IMA lymph nodes. And then once you get outside that

7:43

area so external and common iliac. Those

7:46

are those are considered metastatic disease and internal iliac

7:49

is actually local Regional disease.

7:52

So think about the compartments here

7:55

in this case as well.

7:57

I'm just going to go through.

8:00

The t2 full field of view and we always get full

8:03

field of view images in other patients as

8:06

well at least going up to the aortic bifurcation

8:09

so we can get a good look at whether or not there is lymph

8:12

nenopathy extrinsic to the pelvis

8:15

because again, that's not going to be local Regional disease

8:18

that's going to be distant disease. So I'm going to

8:21

scroll through this again.

8:22

slowly

8:24

and again, just think about teeth stage and

8:27

end stage.

8:29

for this patient

8:31

We'll give it one more go for each sequence and then we can.

8:34

Ask the question. So this is this is actually really interesting

8:37

one which is why I wanted to show it because there's a

8:40

lot of things going on here.

8:43

Okay, so Ryan, let's set up the first question.

8:47

What do you guys think is the T stage for this patient?

8:54

Again, we've got fairly localized

8:57

disease versus Advanced disease.

8:59

1812 versus P4

9:06

Okay. So let's see what you guys thought the majority

9:09

of you thought that was pretty early disease. He

9:12

went to yes and you're correct.

9:15

So this is a small polyp here, which is

9:19

attached to the superficial layer

9:22

of the bowel wall. And one clue

9:25

here that this is a superficial lesion is if you look at

9:28

the angle between the lesion and

9:31

the wall, that's a really good indicator that this is a small

9:34

polyp something that's very superficially

9:37

attached so you can see here. The angle is acute between

9:40

the wall and the border of the ocean and

9:43

again on the other side. You can see that there's an acute angle

9:46

as well. So that that will hold true in

9:49

a lot of Medical Imaging and it does here as well. So if

9:52

this involves the deeper layers of the Bow Wow, you'd expect

9:55

a straight or more convex margin. And in

9:58

this case you have a very nice clean acute

10:01

angle here and you

10:04

really don't see any

10:06

Each of the muscularis propria on any

10:09

of the images. So this is definitely not a T3 or higher lesion

10:12

and it's very difficult. As you know on MRI to distinguish between

10:15

T1 and T2 so we tend to group them together, but you

10:18

could suggest that this is a T1 lesion possibly

10:21

with deeper submucosal Invasion and

10:25

some people feel comfortable doing that others don't

10:28

so it just depends on your level of experience. So well then, okay.

10:31

So the next question is

10:34

the end stage. So let's talk. Let's show that

10:37

question we'll answer and then we'll do some discussing about this case.

10:41

So what's the end stage in this case? So again while you're trying

10:44

to think about it? I'm going to scroll through these images

10:47

again.

10:49

Just to give you a chance to review them.

10:55

So there's a lot going on in this case.

11:00

Okay, so, let's see what you guys thought.

11:03

Okay, so one person said indeterminate and then the other people

11:06

got there's definitely some nodal disease. So

11:10

What's the correct answer? Well, let's go back

11:13

to the sagittal because I think that's very helpful.

11:16

So this looks like a very abnormal rectum

11:19

in the first place. So you can see that the semicosa

11:22

is very pronounced. It's

11:25

very high T2 signal and there's a lot of shagginess to

11:29

the serosa of the rectum here. You can see there's

11:32

these perpendicular lines that are intersecting with

11:35

the serosa and this is not look like

11:38

a normal rectal wall. So the information I didn't tell

11:41

you was that this patient has alternative colitis and it

11:45

would be challenging to

11:48

figure that out. Unless you recognize that there's some sort

11:51

of diffuse pre-existing process based on

11:54

this sort of Shaggy appearance here and the suddenly puzzle

11:57

prominence with that high teaching signal with also

12:00

a clue. So the high teaching signal could be related to

12:03

somebody clinical fat disposition or

12:06

could representative edema. Sometimes you

12:09

see this in patients who

12:10

Previous radiation for other reasons like cervical cancer

12:13

or prostate cancer. So that's where you need

12:16

to do your detective work as a radiologist. Maybe look at old films or

12:19

look through the patient's chart. So it turned out this patient has

12:22

alternative colitis and they had a small polyp which

12:26

had a focus of adenocarcinoma within it. Now the Dilemma

12:29

we were left with was what did

12:32

we do with all these lymph nodes because this patient has a ton

12:35

of lymph nodes. So there's one here, they're both

12:38

intrinsic and extrinsic to the meso rectal

12:41

fascia. So again, pretty abnormal looking nodes

12:44

and then again along the pelvic side while these

12:47

are certainly large spherical irregular nodes.

12:51

Many of them are larger than 9 millimeters short

12:54

axis diameter. And then when you start looking at a

12:57

wider view of the pelvis, you actually get this one

13:00

up here, which is IMA and

13:03

maybe even a little higher so we may be getting

13:06

into the distance lymph node

13:09

territory. So that's when you would want to look at your CT and

13:12

see if there's any any disease higher up

13:15

in the pelvis. So what did we say for this case? Well, because

13:18

the patient has known ulcerative colitis and we

13:21

didn't know how much of this was reactive how much was malignant

13:24

and also given the fact that this is a pretty small superficial

13:27

lesion. It was a polyp with a focus

13:30

of adenocarcinoma and it's the likelihood of diffuse

13:33

with no deposits in this

13:36

case is very low. So we stage

13:39

this is an X in determinate as one

13:42

of you also suggested and that was the reasoning behind

13:45

that. So this is the kind of case where going to tumor board

13:48

and discussing with your surgeons. Radox Etc.

13:51

It's a really good forum because it gives you that added clinical

13:54

information and you might find out if

13:57

there's any older Imaging outside as well. So yeah, so this

14:00

is a quite a challenging case, but I like showing this one just to think outside

14:04

the box again.