0:01

All right, here’s a case where we see that the

0:04

distal ileum has a number of segments of bowel

0:07

that are enhancing, and there’s relative sparing

0:11

of the terminal ileum. But all this area here

0:14

is hyper-enhancing in the distal ileum,

0:15

and you can compare it to the terminal ileum to see

0:17

that it’s clearly abnormal and clearly inflamed.

0:20

But we also see this kind of

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funniness going on over here.

0:23

We need to scrutinize this carefully

0:25

on other planes and other sequences.

0:28

On a coronal image, we see that there’s edema,

0:30

so there’s a degree of active inflammation

0:32

here, most likely, that we need to confirm

0:34

on our fat-saturated sequences.

0:37

And we also see the same thing where it’s

0:40

kind of this funny stuff going on back here,

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extending from the distal ileum to that region.

0:47

And also notice that a lot of this bowel is narrow,

0:53

suggesting that there’s some stricturing component.

0:55

For listening.

0:57

So on the axial sequence, this is where I think we

1:00

can really see exactly what’s going on, knowing that

1:04

all that area here is inflamed and abnormal bowel.

1:07

Now we see that this is our TI coming through

1:10

here. We see a stricture here, and we see maybe

1:13

a little bit of dilation, but more importantly,

1:16

we see this kind of asterisk-shaped abnormality.

1:20

And a lot of times these fistulas, when they

1:23

develop, they have this kind of asterisk

1:26

configuration as everything kind of scars down

1:29

right next to where a fistula’s tract starts to

1:31

form through the repeated cycles of inflammation

1:33

and fibrosis that happens with these cases.

1:36

And so we see this kind of

1:38

branching asterisk scarred appearance.

1:41

And then we can see that this segment here

1:43

is actually a segment of sigmoid colon that’s

1:46

come up adjacent to the distal ileum.

1:50

Additionally, this is the cecum, and this

1:52

is the appendix, and the appendix has got

1:54

itself intertwined with this process.

1:56

So we have a really complex fistula in the

1:58

end, communicating between the sigmoid colon

2:02

and the appendix and the terminal ileum.

2:05

Now, a couple other things to know.

2:09

For one, you don’t see a lot of proximal dilation.

2:12

And when there’s a fistula, oftentimes you

2:16

won’t see the dilation proximally that you would

2:18

expect to see with a significant stricture.

2:21

So when you have a fistula, always be suspicious that

2:23

there’s also a stricture because there usually is.

2:26

The reason you don’t have more proximal

2:28

dilation is because the bowel decompresses

2:31

itself through the fistula’s tract.

2:33

So you won’t get the dilation that

2:35

you’d like to see to call a stricture.

2:37

But there’s clearly a stricture in

2:38

this case that’s proximal to the fistula.

2:41

And in this coronal sequence, you can

2:43

actually see, oftentimes you see this little

2:45

bright fistulous tract surrounded by the

2:49

inflammation and fibrosis around that tract.

2:51

You can see that communicating really

2:52

clearly from the distal ileum to the sigmoid

2:56

colon, and this is the appendix here.

2:58

So this is a complex fistula with a

3:00

classic asterisk-shaped appearance.