0:33

All right, so I wanted to thank MRI Online

0:35

for inviting me back to do this case review

0:38

series and I want to thank you guys for joining

0:39

me live and thank those who go through this

0:43

online once it's available on MRI Online.

0:45

online.

0:46

So to start with, um, this is a review

0:48

of incidental colorectal cancers.

0:50

This is not CT colonography.

0:52

Um, you know, the colons are not

0:56

prepped, they are not insufflated.

0:57

This is CT that was done for a completely other

1:00

reason and colon cancer happened to be on them.

1:03

So just to review quickly some of the common

1:05

features before we dive into these cases.

1:08

Common features of colon

1:09

cancers are abnormal thickening.

1:11

and enhancement.

1:13

The thickening can be circumferential, it can

1:15

be asymmetric, or it can appear as shouldering.

1:18

You can have stranding or inflammatory change,

1:20

because these cancers often have a incitative

1:22

reactive or a fibrotic reaction adjacent to it.

1:27

You can use lymph nodes as a map.

1:28

They may be enlarged and metastatic,

1:30

or they may just be reactive.

1:32

So they may be small lymph nodes,

1:33

but they're in an unusual position.

1:35

Place or positioning and again, you can use that

1:37

as kind of a guide to where the the tumor is They

1:40

can present as an obstruction and then they're of

1:42

course mimics and we'll go over at least one of

1:44

those So what I recommend doing is to run the colon

1:48

every single ct scan you can almost always do it.

1:51

Um, so it's worth doing Uh, I personally recommend

1:54

that the most efficient way is to start at the

1:56

rectum You can waste a little bit of time if

1:58

you're trying to find the cecum if it's not in

2:00

its usual positioning So to start at the rectum,

2:02

it's always where it should be and you can follow

2:04

it back up I also recommend using a coronal in

2:08

particular to confirm or to judge if something

2:10

is peristalsis or if it's abnormal thickening.

2:13

Sometimes the lymph nodes pop out a little bit

2:15

better upstream from it where you didn't necessarily

2:18

notice it before, and I find the sagittals

2:20

are particularly helpful for rectal tumors.

2:23

So with that, we're going to

2:26

start with the first case here.

2:28

So what I'm going to do is I will give

2:30

you the history and I'll slowly scroll

2:32

through the entire CT image here.

2:34

At that point, I'll then start at the

2:36

rectum, go back up and run the entire colon.

2:39

I'll follow with my arrow so you can follow with

2:41

me know kind of where we're looking at there.

2:44

At that point, the poll feature will come up and

2:46

we'll ask you to click any And all features that

2:49

you see if you see the colorectal tumor and even

2:52

if you don't see it I'll then kind of focus on that

2:55

area and kind of scroll through it again to really

2:57

give you uh that picture Okay, so starting with

2:59

this one This is a 91 year old patient who came

3:02

in for trauma The patient fell it had known hip

3:06

fracture on the pelvis x ray and they got a ct scan

3:09

to make sure that there wasn't an injury Elsewhere.

3:20

Okay.

3:20

So hopefully this kind of gives

3:21

you the lay of the land there.

3:22

You saw that left pelvic fracture You

3:25

Pelvic, sorry, hip fracture right here.

3:28

And so starting at the rectum right here, and

3:29

then I will just follow it again with my arrow.

3:32

If we can have the pole feature pop up now, and

3:35

if you see what you think is the colon cancer,

3:37

note any features that you see that are present.

3:40

Some of these will have more than

3:41

one, some of them will only have one.

3:44

None of them are tricks, I promise.

3:49

transverse colon.

3:56

Back up to the flexure,

4:00

and back down.

4:01

And now we reach the cecum, we've

4:03

got to the terminal ileum down here.

4:06

So at this point, I'll go a little

4:08

bit slower over the area of concern.

4:12

That caught my attention when I was reading this.

4:19

And then I'll pause right here for a moment.

4:22

Okay, great.

4:23

So we've got everyone saw thickening there.

4:25

We saw some enhancement.

4:26

We saw some stranding.

4:27

Great.

4:28

A lot of times, this is going to be in the eye

4:30

of the beholder, but here there's definitely,

4:32

definitely abnormal thickening right here.

4:34

You can see paper thin wall of the

4:36

cecum, abnormal thickening here.

4:38

If you look at normal wall back here,

4:41

It's enhancing as it normally should.

4:43

This is a little bit brighter.

4:44

You can put Hounsfield units on these and it will show

4:46

that it's, it's above the background baseline wall.

4:50

But this is also abnormal.

4:51

If you stop on, you know, a particular image,

4:53

you can see a little bit of stranding right here,

4:56

which is also one of the reasons why this is so

4:58

easily mimicked by an acute inflammatory process.

5:02

And so this was highly concerning for a sequel cancer.

5:06

You can also confirm on, I like

5:08

the coronal image in this case.

5:12

And what I think is so beautiful about this, let

5:13

me uh, zoom in here, move that over for you, we

5:19

often think of colon cancer as the classic kind

5:22

of, um, on a fluoroscopic enema type image of

5:25

these apple core lesions, but you don't always

5:27

just see an apple core on CT scan, you kind of

5:30

almost have to reverse what you're thinking here.

5:31

So you have this abnormal thickening

5:33

here, There's clearly a transition right

5:35

here from normal bowel to abnormal bowel.

5:37

And then you have this tiny little lumen right here.

5:39

Here's a little bit more cecum with

5:40

some stool contents, tiny little apocor,

5:43

um, that's remaining of this lumen.

5:45

So this is really an apocor lesion

5:47

that you may not think of that.

5:48

Cause you just see this large circumferential

5:50

enhancing colon cancer right here.

5:52

So this is a pretty straightforward one.

5:54

This is a do not miss lesion, but you can imagine

5:56

this is, could be fairly easy to miss when you're

5:58

looking for other etiologies or problems from

6:01

trauma and a patient who has a known hip fracture.

6:04

Any questions on that one before?

6:07

Um, we move on to the next case.

6:10

So the second case, I'll start

6:12

scrolling through this one as well.

6:13

This is a 31-year-old who was three months postpartum

6:17

when she felt an upper abdominal bulge, felt some

6:20

fullness, and they wanted to rule out a hernia.

6:29

Okay, so I'm sure we all saw that

6:31

the liver is completely and utterly

6:32

abnormal in this particular patient.

6:34

But at this point we'll go through the colon.

6:36

Um, so if we can bring up that the polling.

6:39

Start here at the rectum and we'll head backwards.

6:43

This was a particularly tough

6:44

one because she's fairly thin.

6:46

She has that huge liver, so it pushes a lot and there's

6:49

not a whole lot of mesenteric fat, but I do believe

6:51

you can follow it, even though it's pretty tortuous.

6:53

So here we are at the splenic flexure.

6:58

Into the transverse colon, which is super

6:59

redundant, following it back up here,

7:06

cross back over and our hepatic

7:09

flexure is right around this area.

7:12

Come back up a little bit and head back down and

7:15

here's where the appendix is and the terminal ilium.

7:20

Okay, so this one's a hard one.

7:22

It's a very torturous colon.

7:23

There's a lot going on.

7:24

It's very, very, very easy to

7:26

be distracted by this liver.

7:29

I'll scroll through this

7:30

general area a little bit more.

7:34

And so if you can go ahead and click any

7:35

features, if you, if you found where the

7:37

colon tumor was, you can go ahead and click

7:39

any features that you might see present.

7:41

In this case, I'll also bring up the coronal.

7:44

Again, it shows really just how large

7:46

this liver is by these multiple lesions.

7:51

I've got to find

7:54

the right area.

7:59

Okay, so we saw thickening.

7:59

Thickening is so common.

8:01

That is almost always going to

8:03

be present as a good giveaway.

8:05

Um, abnormal enhancement.

8:06

These are usually going to heterogeneously,

8:08

but they will have increased enhancement.

8:11

Stranding, again, very common.

8:13

There are lymph nodes present.

8:14

So everyone saw thickening, which I agree,

8:16

there's 100 percent thickening here.

8:17

So this is actually the tumor

8:19

right here, this primary tumor.

8:20

This wasn't seen real time.

8:22

And I think part of this is you get sick.

8:23

so distracted, satisfaction of search,

8:25

all these hypo enhancing liver lesions.

8:27

But I would highly recommend that any time you

8:29

see a hypo enhancing liver lesion in a patient,

8:32

I don't, it doesn't matter how old they are.

8:34

This is a 31 year old.

8:36

You want to start thinking of an adenocarcinoma,

8:38

particularly the common adenocarcinomas in general.

8:41

Uh, colon cancer is incredibly common.

8:44

Pancreatic adenocarcinoma also very

8:46

common, not so common in 31 year olds,

8:48

but not a whole lot occurs in them.

8:49

But in any case.

8:51

Anytime you see a hypo enhancing liver lesion

8:53

or multiple lesions, it is absolutely worthwhile

8:56

to pay extra close attention to the colon.

9:00

As oftentimes you'll find the primary tumor.

9:02

And so in this case, she had a very torturous

9:04

colon, but I think not think this is right here.

9:07

It's a little bit of thickening here, little

9:09

bit of extra enhancement in this area.

9:11

And this is very, very subtle.

9:14

Um, but I think it helps.

9:16

to kind of speed along her case because ultimately

9:19

you're going to do the biopsy to stage her, right?

9:21

You're going to get the liver biopsy,

9:22

which is exactly what they did.

9:24

But it can help speed up the management as well

9:26

because they know do they need to get a colorectal

9:28

surgeon involved to divert them potentially?

9:30

Do they need a colonoscopy?

9:32

Do they need a stent to open

9:33

up a near obstructing lesion?

9:35

It can just help speed along that process.

9:38

As opposed to pathologies that may or may not be

9:40

helpful, may be nonspecific with, you know, GI origin.

9:43

So I do think it helps to find

9:45

the organ of origin if possible.

9:47

Here we are on the coronal right here.

9:48

Here is this abnormal thickening.

9:50

Subtle, I think, enhancement and then just there's

9:53

inflammation sort of everywhere in her case and

9:55

it certainly could be from the tumor as well.

9:58

And then as many of you noted, there's a lot going on

10:02

in her, um, you know, little lymph nodes right here,

10:05

little lymph nodes right here in the mesentery that are

10:07

certainly abnormal and likely metastatic more up here

10:10

as well in the hepatic hilum and Rising from there.

10:15

So key points in this one hypo enhancing

10:17

liver lesions Always always always look

10:19

at the colon look at the pancreas as well.

10:21

Give it a second extra special look And then also

10:25

don't fall prey to satisfaction of search when you see

10:28

these liver lesions, you know, you're going to biopsy

10:29

them anyway But if you can find the primary tumor,

10:32

it definitely makes a difference Okay, any questions

10:36

about that case before we move on to the next?

10:39

So this next case is an 88 year old.

10:43

He came into the ED with abdominal pain and

10:47

distension, especially in the lower quadrants.

10:49

He has a history of a triple A

10:51

repair, abdominal aortic aneurysm.

10:53

He got a non contrast scan because

10:55

of chronically poor renal function.

10:59

Again, just giving you the lay of the land here.

11:01

Lots of abnormalities to catch your eye.

11:06

Okay, so if we can put a new poll up, we're

11:08

going to start back here again with the rectum.

11:10

Again, my mouse will kind of

11:11

follow where I'm scrolling through.

11:17

We're up to the splint flexure here, to

11:22

the transverse colon,

11:27

ascending colon, cecum, and terminal ileum down here.

11:30

So again, go ahead and click on

11:31

those if you found the cancer.

11:34

I'm going to scroll slowly

11:35

through the area of most concern,

11:42

and then we'll put this coronal up as well.

11:52

Okay, great.

11:53

So we have some thickening.

11:54

I'll show you the cancer itself was right here.

11:57

This one I think is also particularly hard,

11:59

but that's again why I chose it because it's

12:01

visible, but it's really hard to notice.

12:03

There is some thickening here, but this is

12:05

certainly one where I would be worried that this

12:07

is just peristalsis and I'm over calling something.

12:10

Um, We don't have enhancement because

12:12

it was a non contrast examination.

12:14

Stranding, I think, is a key finding that's here.

12:16

It's very subtle, but you've lost, you got

12:19

a little bit of extra grayness here on this

12:20

side than you do on this border right here,

12:23

and you have it multiple different images.

12:25

So it's not just volume averaging.

12:27

And then lymph nodes is also an important finding.

12:29

So first I just saw this, I was

12:31

like, this, Looks extraluminal.

12:32

We have haziness around it.

12:34

This is stranding, and I was worried about

12:36

that particular area, but I wasn't convinced.

12:38

So I looked on the coronals, and this

12:41

is the area of concern right here.

12:42

And again, you're like, is this just

12:43

peristalsis, or is this abnormal?

12:45

Really hard to tell.

12:46

Here's kind of this haziness right here.

12:50

And then what really caught my eye is once I looked

12:52

on the coronal, and then I'll show you the sagittal

12:54

as well, because then it really caught my eye and

12:56

convinced me, this is the segment of bowel right here.

12:59

And I don't know if you noticed, but I

13:01

can say that I didn't notice when I read

13:02

this at first, at least on the axial.

13:04

Look at all of this abnormal tissue back here.

13:08

All of that.

13:09

That's not the pancreas.

13:09

The pancreas is way up here in this particular case.

13:12

These are all abnormal lymph nodes that on the

13:14

axial, I will confess, I did not even notice.

13:17

Put it on the sagittal because I was

13:18

concerned about this little area.

13:20

And this little area right

13:21

here, a little bit of haziness.

13:22

And you see all of this lymphadenopathy.

13:24

And that to me confirmed that

13:26

this was the primary problem.

13:29

Causing metastatic disease to the liver, because

13:33

if you go back up to the liver, again, it's non

13:35

contrast, but you can see there's heterogeneous

13:37

subtle masses throughout this liver, and

13:40

you almost wonder if that's what's creating

13:41

this almost pseudocirrhosis type of picture.

13:44

They don't have an enlarged stomach.

13:45

spleen.

13:46

So they may not actually have cirrhosis.

13:47

This may just be lumpy, bumpy because it's

13:49

filled with all of these liver lesions.

13:51

Again, which you can confirm on the

13:54

coronal image, you can maybe see them a

13:55

little bit better, all of these lesions.

13:57

So again, in a person of this age, I would

13:58

also certainly consider pancreas as a primary

14:01

tumor, but you can see the pancreas is normal.

14:03

There's no ductal dilation.

14:05

There's no atrophy.

14:06

There's certainly is no

14:07

adenocarcinoma that we could see here.

14:09

The primary, in this case, the lymph nodes and

14:12

the inflammatory stranding lead you to that area.

14:15

In this particular patient, we ended up doing,

14:17

um, radiology did a percutaneous biopsy of one of

14:19

these omental modules, uh, which confirmed that

14:22

it was an adenocarcinoma from the colon as well.

14:26

Any questions on that one

14:27

before we move to the next case?

14:30

All right, so the next case, this is An 81 year

14:34

old male, he presented to the emergency department,

14:37

which is often how they come in, with generalized

14:40

abdominal pain and distention, and they did provide

14:42

us a history of prior omental infarction, which

14:46

I will confess is more history than we often get.

14:51

So he did not have oral contrast.

14:54

Um, He had a fluoroscopic study a

14:56

few days before, which is why there's

14:58

contrast throughout the colon itself.

15:00

You don't usually get that lucky, um,

15:02

to have colon contrast, which would

15:03

certainly help in these kinds of cases.

15:06

So if you can put the pollen question back

15:07

up, start here at the rectum, going back.

15:13

Again, this one's a little easier to follow in

15:14

some ways because he has a lot of visceral fat.

15:17

So it's much easier to follow a colon in

15:19

this particular, um, Um, kind of patient.

15:21

A lot of diverticulum here.

15:24

There's his little mental

15:25

infarct just for fun right there.

15:28

Going back up the descending colon, splenic

15:32

flexure, transverse colon, hepatic flexure,

15:42

descending colon, or sorry, ascending colon,

15:45

terminal ilium there with the fatty valve, and

15:47

the little appendix coming off right there.

15:51

Okay, so we'll go back to the area of concern.

15:56

So if you can choose Any features

15:58

that you see that are present.

16:04

Okay, good So we have stranding everyone

16:06

felt there was stranding and I agree.

16:07

There is some subtle stranding right here There is

16:09

a grayness right here and loss of that, you know,

16:12

beautiful definition between the wall and the fat.

16:14

We've lost that here Um enhancement hard to say

16:18

if there is right here Um, I think I honestly

16:20

do think sometimes the the presence of contrast

16:22

can sort of make that a little bit harder He

16:25

did have contrast on board But I believe it was

16:28

a reduced dose You due to poor kidney function.

16:31

There may be some enhancement

16:32

there or hypo enhancement.

16:34

And then lymph nodes.

16:35

In this particular case, the lymph

16:37

nodes was what cinched it for me here.

16:39

So you can see these large lymph

16:41

nodes that are all heterogeneous.

16:42

They almost kind of match the contrast, which is just

16:44

completely incidental, has nothing to do with it.

16:46

But you see these large lymph nodes.

16:47

And sometimes in the right lower quadrant near

16:50

the terminal ilium, you can see, you know,

16:52

a couple prominent lymph nodes in that area.

16:54

It's very common to see those normally, but you never

16:57

see lymph nodes near the colon at the hepatic flexor.

17:01

It just really doesn't occur.

17:03

So if you're seeing this haziness, you could

17:04

think, Oh, do we have a diverticulitis?

17:06

He has diverticulitis or diverticuli everywhere.

17:09

And that would be a reasonable spot.

17:11

What I like to see though, if I'm going to call

17:13

diverticulitis is to actually see the inflamed

17:16

diverticulum, the thickened inflamed diverticulum.

17:18

And I don't see one here.

17:19

Could you still have one and you just can't see it?

17:21

Absolutely.

17:22

But in those cases, if I think it's a diverticulitis,

17:24

but I'm not 100 percent sure, I'm going to recommend

17:26

a followup or a colonoscopy to make sure that

17:29

there's not an underlying cancer that's causing this.

17:32

Uh, in this case though, you've seen a lot of

17:35

bread and butter diverticulitis type cases.

17:38

You don't get lymph nodes like these.

17:40

So in this particular case, I wouldn't even hedge this.

17:43

Could this be an acute diverticulitis?

17:45

This is a very focal haziness

17:47

right here, inflammatory process.

17:49

I wouldn't hedge this and say,

17:50

let's treat them conservatively.

17:51

Let's get the follow up or let's get a colon,

17:53

a CT colonography or, you know, a virtue or

17:55

a sorry, true colonography, not worth it.

17:58

At this point, these lymph nodes are present.

18:00

This is not normal.

18:00

This is a cancer until proven otherwise.

18:03

So in this case, he also had a few liver meds.

18:06

Which again, should raise your suspicion even more

18:08

that this is not just an incidental diverticulitis.

18:11

This is actually a cancer and causing these metastases.

18:14

So the liver was biopsied and it did find

18:17

an adenocarcinoma of a colonic primary

18:19

and this was the primary tumor right here.

18:22

And again, we said if you're not

18:24

sure, because I wouldn't be sure that

18:25

that was definitely a tumor either.

18:29

Pick a different view.

18:29

And here, even less obvious to me, it, you know,

18:33

there is maybe some luminal narrowing here, but it's

18:35

very hard to argue that that's not just peristalsis.

18:37

Does it look a little bit different than

18:38

this, you know, peristalsis right here?

18:40

It does.

18:41

It is a little bit thicker, so I'm convinced

18:43

it's real, but it's all of these lymph nodes.

18:45

You see all of them, just all of

18:46

these little lymph nodes right here.

18:48

Just this little path, this little track

18:50

of them, that's leading you to this

18:52

being the colon cancer right there.

18:54

So if you have a surgeon who's going to go in after

18:55

it, um, they'll know exactly where they need to go.

19:02

Any questions?

19:03

Otherwise, I will move on to the next case.

19:09

Okay, so for this case, um, I

19:12

have the chest imaging right here.

19:16

But, um, the abdomen pelvis didn't come

19:18

over to my PAX there, so I'm going to

19:20

switch to, um, my normal PAX right here.

19:24

So this is a 55 year old.

19:27

I start right here at the top.

19:29

He came to the ED with abdominal pain and a

19:31

leukocytosis, and he got an IV contrast enhanced exam.

19:39

So if we can have the poll features come up now.

19:44

So we'll start here at the rectum and

19:45

there's a lot going on in this patient.

19:47

We already know there's an obstruction.

19:48

Those are some dilated small bowel loops.

19:51

But because the whole point of this is

19:52

that there is a colorectal cancer present,

19:54

we're going to run it like normal.

20:01

Okay, so just became rectum into sigmoid.

20:03

We have a little bit of free fluid down here.

20:05

Lots of diverticuli.

20:09

This part of the colon, pretty decompressed.

20:13

Try not to get distracted by

20:15

the dilated small bowel loops.

20:16

It's always hard to do.

20:26

Okay, so choose any features that are present,

20:34

and I'll kind of just stop right here.

20:37

Give you some coronavirus as well.

20:48

Okay, thickening, good.

20:49

I'll be honest, you can almost always

20:51

choose thickening, and you will be right.

20:52

It's, it's really one of the more common, um,

20:55

signs on a regular CT scan, um, you know, we're

20:59

not looking for polyps, we're not looking for

21:00

flat little lesions, you're never going to

21:02

see them on a routine CT, but thickening is

21:05

going to show up, you're going to see that.

21:07

Um, and then obstruction.

21:09

So this is a small bowel obstruction, and

21:11

so the question is, do we just happen to

21:12

have a cancer in the colon right there, or

21:15

is Do we, is this all related to one thing?

21:18

Um, we also have some people who chose

21:20

some stranding and some lymph nodes.

21:21

And I would argue this is a little

21:23

bit of stranding right here.

21:24

Subtle, right?

21:25

Very subtle, but it's just this kind of

21:27

blurring of the fat margins right here.

21:29

There's blurring there.

21:30

So that's, that is definitely present.

21:33

So what's interesting about this case

21:35

is we have a small bowel obstruction.

21:36

Next question is, do we have a large bowel obstruction?

21:40

And I'd argue that we do.

21:42

The cecum and the ascending colon are

21:46

fluid filled and they are dilated.

21:48

And they, the transition occurs right here where

21:51

you have this abnormal thickening, this abnormal

21:54

enhancement, a little bit of inflammation,

21:56

which you could better see on the coronal.

21:59

And that is a pretty classic apple

22:01

core lesion that we think of, right?

22:02

This really narrow lumen here, this

22:04

very constricting type of lesion.

22:06

Uh, and it's not Actually, it is

22:09

fairly completely obstructing, right?

22:10

The rest of the colon is pretty much

22:12

decompressed, a little bit of stool getting by.

22:14

So one thing to think about, colon

22:16

cancers can absolutely obstruct.

22:17

The most common cause of a large bowel

22:19

obstruction is actually colon cancers.

22:22

Adhesive disease doesn't normally hit

22:24

the colon like it does the small bowel.

22:26

So if you see a large bowel obstruction,

22:27

that is the first thing you should think

22:29

of as you're looking for other etiologies.

22:31

And what's interesting about these is this

22:33

one also has a small bowel obstruction.

22:35

So you can't get fooled and just think

22:36

the transition is somewhere down here.

22:38

It's not.

22:39

This large bowel is actually

22:40

the transition right up here.

22:42

And the reason this can happen is if

22:44

someone has an incompetent terminal ileal

22:47

valve, meaning that there is, uh, it allows

22:49

reflux, basically, it's not very tight.

22:52

valve there, you can get basically reflux

22:55

and you get a large bowel obstruction

22:56

causing a small bowel obstruction.

22:59

These are actually almost beneficial to the patient

23:02

because they can decompress themselves by vomiting.

23:04

If you have an isolated large bowel obstruction,

23:07

small bowel doesn't dilate, there's really

23:08

nowhere for it to go if it's obstructing bad

23:10

enough until it So this is a colon cancer here.

23:16

At the hepatic flexor, a core type lesion that

23:19

is causing both a large bowel obstruction and

23:21

a small bowel obstruction, which I think is,

23:23

you know, you're never going to miss this if

23:24

you also have the small bowel obstruction.

23:27

The pathology on this, interestingly

23:28

enough, was quote unquote, at least int

23:30

mucosal adenocarcinoma from a colonoscopy.

23:33

'cause that's what they went to.

23:34

First, they need to decide if they're gonna stent

23:36

this, are they gonna see if they can get past this?

23:38

Is this a stricture?

23:39

Is this a cancer?

23:40

And most commonly.

23:41

it's going to be a cancer.

23:43

And again, I think the Corona

23:44

really helps in this case.

23:45

If you're not sure what's going on there,

23:47

it really confirms that there's abnormal

23:48

thickening, abnormal inflammation and certainly

23:51

a narrowing and a transition point occurring

23:53

there that's causing all of this other problem.

23:56

And hopefully you don't get distracted with the

23:58

small bowel obstruction, which is so easy to do.

24:02

Okay.

24:03

Questions on that case.

24:06

So then we will move on to the next case.

24:11

So this is a non contrast 65 year old who,

24:19

sorry, 65 year old who was scanned in the ED.

24:20

The provided history was IV contrast only, and

24:23

as you can see, they didn't get IV contrast,

24:26

so this was really quite an unhelpful history,

24:33

at least to the radiologist, in trying to

24:35

figure out what's going on, what are they

24:37

looking for, what are they concerned about.

24:40

Okay, so if we can bring up the pole everywhere,

24:43

or the pole, it's not a pole everywhere.

24:45

So we'll start again here at the transverse.

25:02

Hepatic flexure, descending cecum,

25:07

got a little appendix back there, and

25:09

there's your terminal ileum coming out.

25:12

Okay, so I'll scroll back through this.

25:17

There's a lot going on here, trying

25:19

to figure out what's happening.

25:20

I'll

25:25

give you a second, oops,

25:32

second view here.

25:38

Okay, obstruction, great.

25:40

So I will say kudos to everyone who picked that

25:43

because that was not actually called on the

25:46

original, we did this cat scan, um, thickening.

25:49

We all voted that there was

25:50

thickening present, um, enhancement.

25:52

There's no enhancement.

25:53

This was a non contrast CT despite the

25:55

history of IV contrast only, they did

25:57

not get contrast so they can't enhance.

25:59

And then we have some stranding and some lymph nodes.

26:01

Okay.

26:01

So we've got a mixture of features that were

26:03

chosen, um, which I think is, again, Very often

26:07

correct when you're coming to colorectal cancer.

26:10

So in this case, we're going to start

26:11

instead of going retrograde here I'm

26:13

going to start in the distal small bowel.

26:14

So we're in the distal ilium right here

26:16

So we do have some fecalized small bowel.

26:18

Fecalized small bowel often is you

26:20

know Your lead or your transition point

26:22

for a small bowel obstruction, right?

26:24

Or just a slow transit type of picture.

26:26

In this case, we don't have a

26:28

small bowel obstruction, right?

26:29

These these loops of small

26:30

bowel are really not dilated.

26:32

They're filled here and there but not dilated.

26:35

get to the cecum, and it's distended,

26:37

and it is very stool filled.

26:39

Very, very, very stool filled.

26:40

Come to the ascending, same thing here.

26:42

And you have this little area right here, which I

26:44

think could probably be passed off as peristalsis.

26:47

Again, if you're moving through quickly right here.

26:50

And then there's more stool beyond it.

26:52

So the question is, why would

26:53

you call this obstruction?

26:55

Because the distal colon, unlike the other case that

26:57

we just showed, still has a good amount, sorry about

27:00

that, still has a good amount of stool that's present.

27:03

But I would argue that Still looks different.

27:06

Again, you, you have symmetry with your colon.

27:08

You have your descending versus your ascending,

27:10

which you can use and is super helpful.

27:12

This colon looks completely

27:14

different than this colon over here.

27:15

This colon looks like it's under pressure.

27:17

It's completely filled.

27:18

It's dilating.

27:19

This is not over here.

27:21

So I'm really worried about this colon.

27:22

The other thing I'm worried about, if you check

27:24

over here, look down here in the paracolic

27:26

gutter, there's a little bit of free fluid, not

27:29

much, but there's a little bit of free fluid.

27:31

And I will say one thing is that if you have a large

27:34

bowel obstruction, doesn't matter where it is, if

27:37

it's in the stigmoid, the descending splenic flexure.

27:41

The place that perforates, if you can't decompress

27:44

into the small bowel, like that last case, if you

27:46

have the incompetent terminal ileal bowel, the place

27:49

where it ruptures, where it perforates, is the cecum.

27:52

The cecum is able to dilate the most, which

27:55

it's doing right here, but then that's where it

27:57

also ruptures because it can dilate the most.

27:59

It eventually doesn't tolerate

28:01

it like a balloon, it bursts.

28:02

Signs of impending rupture.

28:04

It's the free fluid.

28:05

The free fluid is not around the descending colon.

28:07

It's not around the transition point up here.

28:09

That, that fluid is really around the cecum.

28:11

So I would be really worried that this is

28:12

obstructed, even though there's still stool beyond

28:16

this, or this is, you know, nearly obstructed.

28:18

And so then this again, moving back to

28:20

this area right here, That could absolutely

28:23

look like a peristalsis bowel loop, right?

28:25

You could easily get fooled with that, except

28:27

for the secondary signs that are present.

28:29

There is thickening, which again, peristalsis

28:32

can have, but it shouldn't have this here.

28:34

You shouldn't have that tight of a peristalsis

28:37

when you have this much stool behind and

28:39

this much stool in front of you as well.

28:41

So I would be really worried that this

28:43

is actually a shouldering right here.

28:45

There's shouldering right here.

28:46

And this is your tumor right here, and

28:48

this is a different kind of apple core than

28:49

say the first case where it was really the

28:51

thickening, um, was the predominant feature.

28:54

In this case, it's the stricturing, it's

28:56

the narrowing, and it's the shouldering

28:58

that is the predominant feature right here.

29:00

Um, you can use a different view, to

29:04

see if that helps or whether it hinders.

29:09

But again, and this view doesn't

29:10

look like normal peristalsis, right?

29:12

Look how flat this is.

29:13

This is shouldering that's occurring right here.

29:15

This is not morphology of peristalsis.

29:17

So again, if you're never, if you're not

29:19

sure whether something is physiologic or

29:21

not, use your coronal, use your sagittal.

29:23

They will usually help you make a

29:25

reasonable decision, which way to go.

29:27

Um, in this particular case, um, he

29:30

did end up perforating a day later.

29:32

This was, this was missed.

29:33

It was called, um, constipation.

29:36

It was not called an obstruction, but he was

29:37

admitted, um, for other reasons, for pain and

29:40

for trying to get rid of some of the stool.

29:41

He did perforate one day later and had

29:43

to go emergently to the operating room.

29:46

Um, at that point, they did a hemicolectomy

29:48

because they didn't expect a cancer, um, but

29:51

found it there, took out some nodes, which,

29:53

uh, I should say, At least one node right here,

29:55

partially calcified, but definitely a node there.

29:58

And this came back invasive, moderately

29:59

differentiated adenocarcinoma.

30:01

And unfortunately, with that kind of

30:03

perforation, he didn't end up surviving.

30:05

You can just imagine if the cecum perforates,

30:07

all of this stool spills out into the peritoneum.

30:09

And despite, you know, surgeon's best attempts,

30:12

you're just not going to be able to wash this out

30:14

and not have abscess after abscess kind of reoccur.

30:17

It's just, it's really, really challenging.

30:19

Um, so if you made this diagnosis, I'm not saying

30:22

that the outcome would have been any different.

30:24

He may have perforated anyway.

30:25

Um, but this kind of diagnosis, if you see something,

30:28

there's some sort of stricturing, think of cancer

30:30

first, get the colorectal surgery team involved,

30:33

ASAP, not a medical team or someone else where

30:36

they have to then get surgery to be involved.

30:39

Any questions on that case?

30:41

The next case, as we scroll through, this is a

30:44

64 year old who came to the emergency department,

30:47

presenting symptoms were abdominal pain and diarrhea.

30:53

Just give you

30:53

the lay of the land here.

31:01

Okay, so then we can bring the pulling

31:02

feature up.

31:03

We'll start back here at the rectum, tortuous

31:08

sigmoid here, which I think it then comes up over here.

31:17

It's a good example, no matter how

31:18

torturous it gets, you can usually follow.

31:27

Panic flexure,

31:30

coming back down

31:34

into the cecum.

31:37

Okay, so I'll just scroll through this for a

31:52

Okay, so we have some thickening, we have a whole

31:55

lot of stranding, agree, that's absolutely present.

31:58

Um, questionable obstruction, I think that's

32:00

a really reasonable thing to bring up here,

32:02

because it's, it's a little difficult to tell.

32:04

And then we, we've chosen some

32:06

lymph nodes being present as well.

32:08

So this is one of my favorite cases.

32:09

This is, Not classic, but it is not uncommon.

32:13

So this looks like an acute appendicitis, right?

32:16

You have right lower quadrant pain.

32:17

If you looked in their, their chart,

32:19

they probably had a leukocytosis, even

32:21

though we weren't given that history.

32:22

And you have this blind ending tube here, right?

32:25

Ends right there.

32:26

So this is acute appendicitis.

32:27

We have all this inflammation.

32:28

Next case, like go to the, the ED.

32:31

Um, we feel great about this case and move on.

32:34

Um, the problem is you've seen a lot of

32:36

acute appendicitis and the question I have

32:39

for you is you ever seen one that dilated?

32:42

And I would answer, you really don't.

32:43

Generally, you know, maybe a centimeter tops.

32:46

At some point, they will rupture.

32:47

It's an obstructive process.

32:48

That's why you get the acute appendicitis.

32:50

So it's a, it's a rapid obstruction.

32:52

So the thing can't undergo that

32:54

much pressure before it ruptures.

32:55

They just don't get this large.

32:58

Whenever you see an appendix that is this

33:00

large, you could think of a mucocele, but

33:02

those often have a tapered end and don't

33:03

have inflammation surrounding it necessarily.

33:06

But you can think of a slowly obstructing process.

33:09

because that appendix has a lot more laxity if

33:11

it only very slowly and is partially obstructing

33:14

until eventually it completely obstructs.

33:17

It will dilate a whole lot more before

33:19

they present with an acute appendicitis.

33:21

So this is an acute appendicitis.

33:23

We do have inflammation.

33:24

We have a thickened enhancing terminal ileum,

33:27

but once you see one that big, you have to

33:28

start thinking about other things going on.

33:30

Why did that happen?

33:31

Do we have a mucocele?

33:32

And this I would say is not the correct morphology.

33:35

So then you look upstream right here and you notice.

33:37

There is extra thickening, there's extra enhancement,

33:40

and there's often times you'll get, you know, things

33:42

have reactive enhancement or reactive thickening just

33:45

because there's inflammation going on from something

33:47

else, like an appendicitis, you know, an acute

33:49

cholecystitis, something like that, any itis really,

33:53

but you have to figure out where is this centered.

33:55

And this whole thing is inflamed, but this

33:58

colon right here is really not really that

34:00

close to the appendix right there, and

34:01

it's enhancing a bit too much for my taste.

34:04

You look at the coronals as well,

34:06

you've seen a lot of acute appendicitis.

34:07

How many times do you see prominent lymph nodes?

34:11

Not that often.

34:12

It's too abrupt of a process to really

34:15

have like a good reactive lymphadenopathy.

34:17

You might have some, but when you start

34:19

seeing all of these signs together, start

34:21

looking really closely at that cecum.

34:23

And again, you can see the difference here.

34:24

You can see the normal hastral folds.

34:27

You know in the in the upper cecum here and

34:29

you have none of that down here This isn't

34:31

just reactive wall thickening This is a mass

34:33

like tumor and this can happen in cecal tumors.

34:36

They are slow growing So they very slowly partially

34:40

obstruct that appendix until they completely obstruct

34:42

it and then you get an acute appendicitis Except the

34:45

appendix is huge and dilated every colon of cancer.

34:48

I've seen cause an acute.

34:49

Sorry an acute appendicitis and they present

34:52

that way with the acute appendicitis, um,

34:54

it's always these sequel tumors that do it.

34:56

So if you see one that looks like

34:57

that, really take a second look.

34:59

And again, they're going to the

35:00

operating room regardless, right?

35:02

So you could say, what's the

35:03

big deal if you missed this?

35:04

The difference is, um, partially, you know, what

35:07

they're booking the OR time for, who's going to do it?

35:10

Is this, you know, an emergency general surgery service

35:12

who does these things, you know, laparoscopically and

35:14

is used to just taking out an appendix in no time flat?

35:17

Or do you need a colorectal team

35:18

who still do it laparoscopically?

35:20

but may have to do a little bit more invasive of

35:23

a surgery to do a hemicolectomy instead, right?

35:25

You want the right surgeon to be involved, to do

35:28

the right procedure the first time, so you don't

35:30

have to go in a second time and kind of fix that

35:32

hemicolectomy, take out any possible nodes, um, you

35:37

know, which is certainly much better for the patient.

35:39

Um, secondary question on this was if there was

35:41

obstruction and, It's a really good question.

35:44

I don't think it's a flat out obstruction.

35:46

You know, these dilate or these small bowel

35:47

loops up here aren't that dilated, but you really

35:49

do have this fecalized kind of prominent, you

35:52

know, distal and terminal ileum right here.

35:54

I don't know if this is an ileus because of all this

35:56

inflammation here, or is this almost obstructing

35:59

and we get this fecalized small bowel loops because

36:02

of the sequel tumor here, or again, is it all

36:03

reactive due to the appendicitis And that's really

36:08

causing, you know, the, the cecum tumor caused

36:11

the appendicitis, which caused the, um, sort of

36:14

ileus and small bowel fecalization sign here.

36:16

Hard to tell, wouldn't know necessarily.

36:20

good to bring up, but they certainly don't

36:22

need NG2 decompression at this point.

36:24

They need a surgery which will

36:25

fix all of those problems.

36:27

Um, so this one did come out, um, and the pathology

36:30

was a mucinous adenocarcinoma of the cecum.

36:33

I don't think you can tell that.

36:34

This isn't a mucocele or, you

36:36

know, a mucocele gone wrong.

36:38

The appendix was not the site of the tumor.

36:40

It was a sequel tumor.

36:41

It just happened to be a mucinous

36:43

variant of an adenocarcinoma.

36:47

Okay, any questions on that one

36:49

before we go on to the next case?

36:52

All right, so this case is a 58 year old.

36:55

He came to the emergency room, um, with a

36:58

history of pain, rule out diverticulitis,

37:01

comma, renal stone, comma, aorta.

37:02

That was the history that we gave.

37:07

So I'll already say you can tell there's going to

37:08

be something wrong with this left kidney, right?

37:10

We have a delayed nephrogram.

37:12

We have hydronephrosis.

37:12

So we probably have a kidney stone.

37:13

We already know that.

37:15

Uh, well, we know that already.

37:17

Um, but there's your stone right there.

37:20

But since this is a colorectal case review,

37:23

You have to be thorough with these, right?

37:25

We can't fall prey to the satisfaction of search.

37:29

Okay, so if we can bring the poll up

37:31

here, we'll start here at the rectum.

37:32

Descending,

37:41

transverse,

37:45

patekflex, descending, cecum,

37:50

appendix, terminal ilium right here.

37:52

Okay, so I will bring you to the area

37:54

of concern because this is a hard one.

37:59

And I'll just

38:00

scroll through the area.

38:08

This one's really

38:08

hard.

38:09

Um, this was sort of a, a almost not applicable one.

38:14

In this particular case, a resident over read this,

38:16

or sorry, read this first before I got to it and

38:18

said, you know, I feel like I'm seeing something,

38:21

but is there a tumor, like a polypoid tumor in the

38:24

rectum, or am I being crazy and this is just stool?

38:27

And so they were concerned about this particular area.

38:29

This is what caught their eye, you know,

38:31

and you're wondering, is there a little bit

38:32

of enhancement or is this just a little bit

38:34

of death, a little desiccated, you know,

38:36

hyperdense stool, or is this real enhancement?

38:38

You know, is this, you know, a thickened

38:40

polypoid type mass here, or is it, is it nothing?

38:43

You know, and then you're looking at this area,

38:45

like is this, is this too much vascularity here?

38:49

Is that normal?

38:49

Is it not normal?

38:50

And so you could go back and forth and scroll back and

38:52

forth through this and not make up a decision at all.

38:55

Um, But if you go to the coronal, again your

38:59

secondary views will save you every single time.

39:02

Here we are at the sigmoid right here, you're heading

39:04

backwards, and I will stop on that image right there.

39:08

I think this is a beautiful image that

39:10

shows, here's your rectum, here is a

39:12

mass, there's a polypoid lobulated mass.

39:16

Stool does not look like this.

39:17

You scroll through it, and now you

39:19

see the vascularity come out, right?

39:21

So here's the vascularity.

39:22

We kind of questioned that before.

39:24

Is that straining?

39:24

Is that vascularity?

39:25

You can watch it come in right here.

39:28

This feeding vessel is feeding this

39:30

polypoid type tumor right here.

39:33

Again, I said rectal tumors, often

39:34

the sagittal will help you as well.

39:37

In this case, I don't think you needed it.

39:41

But I do think it demonstrates the

39:42

vascularity beautifully, right?

39:44

You have rectum coming back here.

39:46

You have all this vascularity.

39:47

You can see how it almost pinches

39:48

in and feeds this mass in here.

39:53

So I don't have pathology on this yet

39:55

because this case just occurred last

39:56

week, but he is scheduled to get one.

39:59

We had actually a CTA from a year prior.

40:02

So if you compare back, that's

40:03

the other thing I like to do.

40:04

If you have a fairly recent prior within a year,

40:06

look back There is almost always a hint that

40:09

there was a cancer there at some point and you

40:12

could actually see there was something very small

40:14

in the rectum at that point, something that you

40:15

wouldn't necessarily call, but it was just another

40:18

confirmatory sign for me that this was real.

40:21

We had the vascularity, we have a lobulated

40:23

intrarectal mass, um, and there was

40:26

something a year ago that was present.

40:28

Um, so this is going to be a

40:29

cancer until proven otherwise.

40:32

Okay.

40:34

And if there aren't questions on that

40:36

one, we will move to the very last case.

40:40

So this case, uh, wasn't 100 percent incidental.

40:43

This was a 35 year old female, and she actually came

40:47

to the ED because she had altered mental status.

40:50

Because of that, they started with a

40:52

head CT, which showed a posterior fossa

40:54

mass, which I'm not going to show you.

40:56

So then they immediately got the CT to look for a

40:58

primary tumor, um, to decide, are they going to biopsy

41:02

the brain mass, or are they going to go somewhere else?

41:05

Um, I will mention in a, you know, in a 35 year

41:07

old, things you can think about are breast cancers.

41:08

I did note these breast, breast

41:11

lesion here, breast lesion here.

41:13

They did end up pursuing those and they ended

41:15

up being fibroadenomas, but certainly reasonable

41:17

to always think of a breast cancer in a young

41:19

female presenting with what is presumed a

41:21

brain metastasis as opposed to a primary.

41:24

So there's like, I'll scroll through

41:25

this and let you get the lay of the land.

41:31

Okay, and she's young and she's skinny.

41:33

This is the gadolinium.

41:35

Or sorry, the CT.

41:37

I think she had a brain MRI as well.

41:38

Um, so this is excreted gadolinium, um,

41:41

because we get everything in our ED.

41:43

Um, if we can bring up the poll results,

41:45

we'll start from the rectum and go backwards.

41:51

And I'm going to try and follow it for you, but

41:53

she's, she is thin, so I will fully admit this was

41:57

a hard colon to follow, and sometimes I'll go the

42:01

wrong way because I make a guess and I'm wrong,

42:03

but you, you can still, you can always follow it.

42:06

And come back here,

42:10

or almost always.

42:15

Okay, we've made it to the splenic flexure,

42:22

all the way to the hepatic.

42:26

And we've got a little appendix, so

42:27

we've reached the end of the colon.

42:28

Okay, so go ahead and click on your features that you

42:30

think are present, and I will scroll over the area

42:34

of concern.

42:43

All right, thickening,

42:44

enhancement, stranding.

42:45

Great.

42:46

So this one I chose because it has virtually

42:49

every feature and you can't even argue

42:50

with it and say, eh, maybe, maybe not.

42:53

Um, I will also admit this was one of the

42:54

earlier ones that I, that I read in my career.

42:57

So I wasn't quite as sure that this was a

42:59

rectal tumor, but now in retrospect after

43:01

having looked at tons of cases like these,

43:04

um, this one is clear as day in my mind.

43:06

But so I can guarantee if you start looking

43:09

for these, Uh, you will find them and then

43:11

it becomes clearer and more obvious when

43:13

they are real versus when they're not.

43:15

But this case, um, again, we went after that

43:17

breast lesion which ended up being nothing.

43:19

Um, but you have a whole lot, a lot of

43:22

inflammation in the perirectal fat, right?

43:24

There's no normal fat here.

43:25

It's all grayed out.

43:27

You know, you can question, do we

43:28

have a few lymph nodes back here?

43:29

Hard to tell.

43:31

But we do have abnormal thickening here.

43:33

You have all this fuzziness right here.

43:35

You've lost your discrete borders.

43:37

You have some enhancement changes.

43:39

It's higher enhancing here than

43:41

it is the rest of the rectum.

43:43

You're compared to the sigmoid over here.

43:46

And then again, I told you for rectal

43:47

tumors, I really like sagittals.

43:49

This is what sealed the deal for me on this one.

43:52

That made me comfortable to call this.

43:54

The tumor itself may be not quite as obvious.

43:57

Here on the sagittal.

43:57

Let me zoom in a little bit as well.

43:59

Perfect.

44:04

Um, again, rectum here.

44:07

This is the tumor right here.

44:08

Not the most obvious right here.

44:10

But what kind of sealed it for me was the lymph nodes.

44:12

I saw this soft tissue right here

44:14

that didn't really connect with the

44:15

vessel, just soft tissue sitting there.

44:17

And if you see soft tissue

44:18

sitting Again, right here as well.

44:20

In that kind of pre sacral space, rectal

44:22

tumors love to start having lymph nodes

44:25

right here in the mesorectal fascia.

44:26

You know, it's one of the MR staging

44:28

things that you need to look for.

44:29

Not as obvious on CT, but if you see it, I feel

44:32

like they are the most obvious to me that they're

44:34

real when you look on the sagittal sequence.

44:37

So I really love the sagittal when

44:38

you're considering a rectal tumor.

44:42

So that one pretty much had everything.

44:43

every feature that you could look for except

44:45

obstruction that you could argue maybe it's

44:47

almost obstructing because there's a whole

44:49

lot of stool, you know, that's in the rest of

44:51

her colon there, um, but not yet obstructing.

44:55

I also say that rectal cancer is very, very

44:58

rarely obstructs and I don't know why that is.

45:00

Um, they can certainly narrow, but obstruction

45:03

is just not as common in that case.

45:05

Um, in her case, um, the follow up for her was that

45:08

she had, they ended up doing, um, a brain biopsy

45:11

because the lesion was large enough and it was

45:12

isolated, so they just took it out to decompress.

45:15

Came back metastatic adenocarcinoma of a GI primary.

45:18

She did have a follow up colonoscopy, which

45:20

proved as well that there's an invasive, it's

45:23

considered a low grade adenocarcinoma, which

45:25

is Always seems like a misnomer for a low

45:27

grade that already metastasized to the brain.

45:29

Um, but she did well after that.

45:33

So in conclusion, I'll bring my PowerPoint back over.

45:36

My best advice, colon cancer is super, super common.

45:39

So you're going to find it on these, you know, on

45:42

these regular CTs as an incidental finding and you

45:44

are more likely to find them if you look for it.

45:47

I really do run the colon every single time

45:49

and I highly, highly recommend doing that.

45:51

You will find these and it's really

45:53

satisfying as a radiologist to find

45:55

them because you've made a difference.

45:56

especially if you catch it before it's metastasized.

46:00

Second is reconstructions are your friends in this.

46:03

They've saved me multiple times where I was going

46:05

to under call something or I was going to over

46:07

call a peristalsis or just a decompressed loop.

46:10

They will save you and they will

46:11

help convince you which way to go.

46:13

Is this real?

46:14

Is it not real?

46:16

And then the last pearl that I want to give you is

46:17

that most colorectal features as you've seen with

46:19

these poll results and your choices here, most of them

46:23

will have more than one feature to help convince you.

46:25

Confirm the hardest ones are when you only have one

46:27

feature like that one narrowing that just abstracted

46:30

the large bowel That one's a lot harder when

46:32

it's only one feature Most of them will have more

46:35

especially if you have IV contrast So just remember

46:37

that you have multiple things that you can look

46:39

for Even though it's variable and all the cancers

46:42

present differently which makes it makes it hard,

46:45

makes it a challenge, but it certainly can be done.

46:48

So with that in mind, um, that

46:51

is the end of the case review.

46:52

So if anybody has any questions or

46:53

comments, I'm happy to answer those.

46:56

Thanks everyone.