0:00

Okay, let's look at the typical appearances of polyps.

0:04

The classic teaching is that, uh, stool, um,

0:08

residual stool has angulated

0:10

or branched appearance on the two D views.

0:14

Um, and, uh, is, uh, heterogeneous in appearance

0:17

with typically contains some air.

0:19

Well, polyps typically have a homogeneous ovoid

0:24

or rounded appearance.

0:25

Um, and, uh, you can see the, uh, uh,

0:29

three D view here as well.

0:31

Again, for the five millimeter

0:33

and smaller lesions, which are considered dimi diminutive.

0:37

You do not need to report these, so don't spend a whole lot

0:40

of time trying to problem solve these little, uh,

0:43

these very little lesions.

0:45

Um, the six to nine millimeter lesions are considered small.

0:48

You have to report these.

0:50

And then 10 millimeter

0:51

and above are considered large lesions.

0:54

Here again, is very nice demonstration

0:56

of a large calculated polyp.

0:59

Uh, you can see on the two D view

1:00

that there is a coating of contrast.

1:03

Um, when you measure these lesions here,

1:06

normally I would recommend that you measure on three D,

1:08

but when you have a coating of contrast, I would go

1:11

to the two D actually to measure,

1:13

'cause I wanna exclude that contrast cap.

1:18

Here's a case that was very interesting,

1:20

where on the two D view on top, it's very hard

1:23

to tell what's going on.

1:25

And, uh, you can see that there's a soft tissue density,

1:29

um, with the head here.

1:30

And then there's something else coming off here.

1:32

I think that the three D view is very helpful in showing us

1:36

that we have actually two large populated polyps coming off

1:40

of the same fold.

1:42

So here's populated polyp one, here's the stalk

1:46

and the head, and then we turn your, your, uh, perspective.

1:49

And here's the long stalk of polyp number two, uh,

1:53

with the head hiding right behind this fold.

1:57

Um, and here's my demonstration of both polyps.

1:59

Again, you can have very irregular morphology

2:04

to polyps, uh, just to note.

2:06

And, uh, this angular shape, as I mentioned

2:08

before, was, is typically seen with a stool.

2:11

But in this particular case, um,

2:13

you wanna use your two D views

2:15

and shows that it was homogeneous soft tissue,

2:18

and then clearly a true polyp.

2:19

And then here's another lobulated polyp.

2:22

Again, when you see things like this on three D,

2:24

if you're a primary three d uh, reader, you have

2:26

to use your two Ds, uh, to look at the soft tissue density.

2:30

Here's a, um, club shaped, uh, polyp.

2:34

Again, you go to your two D view, uh, soft tissue density,

2:37

clearly a, uh, true polyp.

2:44

Um, we will always have to use the maximum diameter

2:49

of, uh, polyps, uh, in the report.

2:52

Why is because your gastroenterologist cannot tell the

2:55

volume, um, when they're performing the

2:58

Colonoscopy, and they always wanna correlate

3:00

with the maximum diameter.

3:02

So it's not irrespective

3:03

of whether it's the length or the width.

3:05

You really need to look at both, uh, at the,

3:08

on the three D view and measure the, just the largest, uh,

3:11

diameter, whatever direction that's in.

3:13

And just, this is just, that was from

3:15

a question that I just thought.

3:16

This is a, uh, discoid type, irregular shape polyp.

3:20

And you can see the morphology is, um, very irregular,

3:25

both on the, uh, three D and the two D.

3:28

What about this case where on the two D you do see this sort

3:32

of angular shape,

3:33

but when you look at it on the three D, you see

3:36

that there is a short stock.

3:38

Um, and, uh, all

3:40

that this represented was an inflated rectal balloon

3:44

that's flattening this, uh, undulated polyp.

3:47

And that's causing, uh,

3:49

the angulated appearance on the tubie.

3:53

And what about this case?

3:54

Uh, where on the top row you see that, uh, the, uh,

3:59

rectal balloon has been inflated.

4:01

Um, and when you deflated, you can see what pops up Is this,

4:06

uh, true polyp.

4:08

So the recommendation is that in at least one position

4:12

that you should deflate the rectal balloon.

4:15

Um, if you are actually using, uh,

4:18

an inflated rectal balloon at my site,

4:20

you don't actually typically inflate the balloon.

4:23

Um, and we're able to actually still achieve, um, adequate,

4:27

um, uh, colon distension

4:31

flat lesions are tough.

4:34

Uh, I think for the radiologist, um, I, you, you do need

4:38

to use soft tissue windows.

4:40

When you look at the colon window here, um, it's very,

4:43

really hard, I think, to identify a lesion.

4:45

But when you look at this on the soft tissue windows, um,

4:49

you can clearly see that there's more focal lobulated,

4:52

irregular soft tissue.

4:54

And, uh, this turned out to be, um, a rated lesion.

4:58

Here's another example of just irregular focal, uh,

5:02

soft tissue along the anterior wall on superior,

5:04

on the supine and the prone along the anterior wall.

5:07

Um, again, this was a true lesion

5:09

and you can see it also on the three D view.

5:12

Now I'm gonna tell you a trick, which is that a tagging, um,

5:17

often can help you to find these lesions.

5:20

Why is because the majority

5:21

of these lesions will have a contrast coat

5:24

that highlights the lesion for us to find.

5:27

So in particular here you can see this lesion has, um, a,

5:31

uh, coat of contrast on its surface, uh,

5:34

and you're able to spot it

5:36

and, uh, correlate it with the three D view.

5:38

I think it's harder to see on the three D view than on the,

5:41

um, optical colonoscopy view.

5:43

Here. It's again, the opposing view.

5:46

I think the, the contrast coating nicely highlights, uh,

5:50

this flat patient and here again on the supine and prone.

5:55

And then on the coronal view, um,

5:57

the contrast really draws your eye, uh, to the lesion.

6:02

And this was a study, uh, published

6:04

by David Kim looking at flat polyps.

6:07

Um, 80% of them, uh, showed a, uh, coat of contrast.

6:12

These tended to be, uh, on the large slide, so, um,

6:16

a little over nine millimeters in wheat size.

6:19

There were three factors that they found

6:21

that were associated with this contrast coating.

6:24

So the large size, uh, 10 millimeters

6:26

above if it was located in the right colon,

6:29

so an proximal location.

6:31

And then, um, if it was a serrated, uh, histology,

6:35

and we'll talk more about this.

6:37

I dunno how many of you know this,

6:39

but there are actually different pathways, uh,

6:42

for the development of colorectal cancer.

6:44

I think all of us are familiar with the adenoma carcinoma

6:48

sequence to developing colorectal cancer,

6:50

where you go from a normal colon to a small adenoma

6:54

and then to a larger one.

6:56

And then, uh, um, evolution to colorectal cancer,

7:00

you have the non-point pathway to colon cancer.

7:03

And typically this occurs in patients

7:06

with inflammatory bowel disease, uh,

7:08

like ulcerative colitis and Crohn's disease.

7:11

And then there's this third serrated

7:12

pathway to colon cancer.

7:14

And hyperplastic polyps, which are, uh,

7:17

benign, are in this pathway.

7:19

Um, so hyperplastic polyps themselves are benign,

7:23

but they are, uh, in the pathway for the development

7:25

of the cess serrated polyp,

7:27

which then can evolve into colorectal cancer.

7:31

And it's thought that up to about 20% of colorectal cancers

7:35

actually develop from this serrated polyp, uh, pathway.

7:40

So the World Health Organization has, um,

7:43

classified rated polyps into three types.

7:47

We have a hyperplastic polyp, as I mentioned,

7:49

and these represent the majority, 70% of serrated polyps.

7:54

The cile serrated polyp

7:55

or cile rated adenoma represents 25% of,

8:00

uh, serrated polyps.

8:01

And then you have the traditional ser adenoma, the TSA, uh,

8:05

which is the minority, only 5% of rated polyps.

8:10

Now, the good news is that the C cell rated polyp

8:13

and the traditional serrated adenoma both, um,

8:17

exude this mucin cap.

8:19

And it's thought that it's the electrostatic properties

8:22

between this mu cap

8:25

and the, uh, tagging product.

8:28

So the barium product in particular that causes, uh,

8:32

this contrast cap.

8:34

Um, I don't think that it's, uh, actually, um,

8:37

absolutely been proven that it's the barium that that, uh,

8:41

in only the barium that causes the cap.

8:44

Um, but that, um, I need a contrast potentially, um,

8:48

may be involved in this cap as well.

8:50

It's just not known currently.

8:53

So this is a summary chart just

8:54

To, to go over with you that, um,

8:57

adenomas can have various morphologies.

9:00

Um, they are relatively common, um,

9:04

more common in the right colon than the left.

9:07

Uh, and they are, uh, pre malignants.

9:10

Um, the CES rated polyp in the traditional serrated adenoma

9:15

are also pre-malignant.

9:16

The cile serrated polyp tends to be flat in morphology, uh,

9:21

larger, they're, uh, more common, uh,

9:24

than the traditional serrated adenoma,

9:26

and they tend to be in the right hole.

9:28

In contrast, the traditional serrated adenoma

9:32

can be smaller, large, um,

9:34

and when they're, uh, smaller, they tend

9:36

to be sessile, as I mentioned.

9:38

They're uncommon. Um,

9:39

and they tend to occur in the left colon.

9:41

So in the distal colon, they also can be

9:44

irregular morphology.

9:46

When they are, they tend to be larger.

9:48

So I'm gonna show you a, a study

9:51

that was just published looking at these TSAs, uh,

9:54

on CT colonography.

9:56

Um, and this is international experience.

9:59

Um, and you can see that, um, over, uh,

10:01

65% were located in the left colon.

10:04

So the, uh, colon mean size of, uh,

10:08

almost 20 millimeters, again, when they were larger,

10:11

they tended to be irregular

10:13

or lobulated, even carpet like, uh, in morphology.

10:17

And of note, um,

10:18

and good for us is that almost 90% of them

10:22

actually have contrast coating.

10:28

Artificial intelligence algorithms have been developed

10:31

trying to find these serrated polyps

10:33

and they've been developed in particular to look

10:35

for this contrast coating

10:37

'cause there's high, um, association

10:39

of the coating with these polyps.

10:41

You can see that in this one study

10:43

that was presented at RCA last year,

10:46

that they were very successful at, um, over 94

10:50

and 96%, um, sensitivity

10:53

for identifying these rated polyps, um, based on size,

10:57

but very successful, uh,

10:59

because they used an AI algorithm that actually found

11:03

contrast coating on the surface of this rated, uh, Palo.