0:01

So up to this point, I've shown you some cases

0:02

of some pretty severe disease stuff that's pretty

0:05

clearly Crohn's disease, and for this case, we're going

0:08

to talk about something that's a lot more subtle.

0:10

So in this case, we have someone with a T.I.

0:13

7 00:00:13,780 --> 00:00:16,079 that looks like it may be mildly thickened,

0:16

and this is someone with Crohn's disease,

0:18

and they're wondering if it's a normal T.I.

0:20

11 00:00:20,850 --> 00:00:22,430 or an abnormal exam.

0:23

It can be tough sometimes to decide whether

0:26

the thickening in the terminal ileum is normal or

0:29

abnormal, and so in this case, on the T2 series,

0:32

it looks like it may be a little bit thickened,

0:34

but it also looks relatively decompressed, and,

0:37

you know, as we look at other loops of bowel that are

0:38

decompressed, some of them look similarly thick,

0:40

so it's a little hard to tell if we're going

0:43

to say that this is truly normal or abnormal.

0:46

Um, when we look at our enhancement, it doesn't seem

0:48

to help us much because it's not really enhancing

0:50

a whole lot more than adjacent loops of ileum.

0:54

It seems like it may be a little bit of hyper-

0:55

enhancing, but not markedly hyper-enhancing.

0:58

When we look at our axial cuts,

1:01

we kind of see the same decompressed look.

1:03

And if this coronal truth is, it looks

1:05

like it may even be a little bit

1:08

more distended, and it's not as thickened.

1:10

So we're questioning whether any disease at

1:12

all is involving this loop of terminal ileum.

1:15

And this is the type of case where

1:17

I think diffusion really comes in handy.

1:19

And one of the big advantages of diffusion is

1:22

it's a very sensitive detector of abnormality.

1:26

And it's not necessarily active inflammation.

1:28

It can be chronic changes of Crohn's

1:30

disease that can have diffusion restriction.

1:32

And so when we look at our diffusion sequence in that

1:35

area, we can see how bright that terminal ileum is.

1:39

And it's clear that this is someone who has

1:42

pathology involving their terminal ileum.

1:44

So if they did a biopsy here, they would expect to

1:46

see some changes related to their Crohn's disease.

1:51

Now, this could be acute or

1:54

chronic, and so be very careful.

1:56

A lot of people have tried to show that

1:58

diffusion is better for acute or chronic disease.

2:01

And my reading of those studies is that it's not

2:04

highly specific for acute versus chronic disease.

2:06

But what it is good for, and pretty clearly, is

2:09

identifying areas of the bowel that do have disease.

2:13

So sometimes it can be a case like this,

2:15

where this is the only segment of the bowel

2:17

where we're suspicious there may

2:19

be some involvement with Crohn's.

2:20

Other cases, you may have a segment where you

2:23

know there's Crohn's, but the diffusion picks

2:25

up a skipped lesion or another segment, which

2:28

puts them in a higher severity of disease.

2:31

So I would strongly advocate that you use diffusion

2:34

these days when you do your MR enterography.

2:37

We do it in the axial plane.

2:38

Some people do it in the coronal plane.

2:40

I think either works depending on what's more

2:42

efficient for your scanner, but including

2:44

diffusion can be really helpful to improve

2:46

your sensitivity for disease detection.