0:01

Okay, so for this case, you can see a clear

0:03

abnormality in the terminal ileum here.

0:06

So here's the cecum here, here's the

0:08

ileocecal valve, and here's the terminal ileum.

0:09

And there's a long segment of clear wall thickening.

0:13

And so this is the patient with known Crohn's

0:15

disease and really fairly long-standing disease.

0:18

It's been getting regular disease monitoring.

0:21

And on this exam,

0:22

What we see is this long segment of narrowing.

0:26

Proximal to that, there's at least some dilation.

0:28

So this would definitely be characterized as a

0:31

stricture, and it's a fairly long segment stricture.

0:33

Note that the proximal dilation isn't too severe.

0:37

So on this T2 sequence, there's a

0:39

lot of bright signal in the wall.

0:41

So we think that maybe there is a good

0:43

amount of edema, but we want to verify

0:45

that with something with fat saturation.

0:48

In this case, we're looking at a true FISP

0:50

or a steady-state free precession image.

0:52

And we can see that some of that edema is certainly

0:55

real, that there are areas of that bowel wall that do

0:58

look brighter than the adjacent skeletal muscle.

1:01

However, there are also areas that are dropping

1:03

out on the fat-saturated sequence, so there's

1:05

also some chronic fat, so that's accounting

1:07

for some of that increased T2 signal.

1:09

But, importantly, there's not a lot of surrounding

1:13

inflammation or surrounding changes that we're seeing.

1:17

And we want to look at our post-contrast

1:20

images to help us further characterize this

1:22

and we see some patchy areas of enhancement.

1:25

So this suggests there are some acute and

1:27

some chronic changes with fat in the wall.

1:30

And then this patient with long-standing disease,

1:33

it's likely a mixture of acute and chronic changes.

1:36

But we also see, as I've been scrolling

1:38

through, you may have already noticed

1:39

that there's something going on here.

1:41

Or this loop of bowel does seem to

1:44

communicate with this adjacent loop of bowel.

1:46

And that is concerning, obviously, for a

1:50

fistula related to this long segment stricture.

1:52

So to further characterize that,

1:54

let's look at an axial plane.

1:56

And here you can clearly see this is that same area

1:58

of thickened fat and edematous containing bowel.

2:03

And as it comes down here, we see the sigmoid

2:06

colon coming towards that loop of bowel and we see

2:10

it communicating, and additionally, there's another

2:12

loop of small bowel. This is another loop of ileum

2:15

that's also communicating.

2:16

So there's a complex fistula with that asterisk

2:19

appearance, and you can confirm this is

2:22

the sigmoid colon by following it down from the

2:24

rectum up. So it's clearly a sigmoid colon. So this

2:27

was a new finding, and this patient has been on

2:30

multiple anti-inflammatory drugs for a long time.

2:33

And has never really fully gotten rid of that

2:36

inflammation, and eventually, this stricture formed.

2:40

So, at this point, the clinicians are stuck

2:44

with disease that just seems to be resistant

2:46

to the drugs that they're able to offer.

2:48

And they consulted the surgeon, and

2:50

the surgeon decided to do a resection.

2:52

Which makes sense because once you

2:53

have these fistulizing components,

2:55

it's very hard to improve that.

2:57

They may at times delay it if there's a lot

2:59

of inflammation, but there's not a lot of

3:01

surrounding inflammation around this loop of bowel.

3:03

So surgical resection appeared to

3:05

be a great option for management.

3:08

So that's what they did.

3:09

And we also have some postoperative

3:11

imaging for this case.

3:13

And following the surgery, what you see is they did

3:16

what they typically do, which is a right hemicolectomy.

3:19

Or at least removal of the cecum and removal of

3:23

the diseased distal ileum with creation of what

3:26

we call a neo terminal ileum, and it's a little

3:29

hard to follow, potentially, and these cases can

3:32

be a little more difficult because anatomy is

3:33

distorted and you no longer have an ileocecal

3:36

valve to help you find the terminal ileum.

3:38

But what we can see here is this is

3:40

the ascending colon. It comes down.

3:42

And it communicates with this loop of bowel here.

3:46

Here's where they put that anastomosis together.

3:48

We'll look at it again on a post-contrast image.

3:51

And you can see a little bit of artifact probably

3:53

from the surgical clips and anastomosis.

3:56

It can be really hard to see that

3:58

on MRI, but sometimes you see it.

4:00

And obviously on CT, it's

4:02

really quite obvious typically.

4:04

So for these post-surgical cases, we'll talk

4:06

about how to evaluate those in our next section.