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So this patient is a 54-year-old male, and his

0:04

history provided is biliary obstruction suspected.

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These are the histories that we are often given,

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and so we're looking at pretty much all the

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biliary structures, bile ducts, certainly the

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gallbladder, telothrania abnormalities, and

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we did a non-contrast MRI of the abdomen with

0:19

an MRCP to evaluate this patient's symptoms.

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So, start off with our T2 non-fat saturated image,

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the axial plane, focusing on the gallbladder.

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I'll just scroll through the images one time.

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And then we'll start to discuss, uh,

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some of the findings that we're seeing.

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So if we just look at the gallbladder itself, uh,

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we can see this round T2 hypointense structure

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that certainly looks like a stone over there.

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We can see that there is other, uh, stuff over

0:46

here that's relatively layering that may be a

0:49

little bit of sludge within the gallbladder itself.

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Some of it looks a little bit

0:52

more mass-like in its appearance.

0:54

We've discussed, uh, you know,

0:55

sludge and things like that.

0:57

And, uh, and prior

0:59

clinical vignettes.

1:00

We notice that the gallbladder wall is also

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quite thickened over here, and it has T2 hyper

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intense signal within it, and that's a sign of

1:08

gallbladder wall thickening and edema as well.

1:10

So that's something we'll make note of.

1:12

The gallbladder itself looks a little bit more

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distended than we're used to, so if you were

1:16

to measure it here, certainly it's at the upper

1:19

limits of normal in this imaging, four centimeters,

1:22

but just looking at it in different planes, you

1:24

get the sense that it's even a little bit more

1:27

than what normal would be at four centimeters.

1:30

But I think one of the things that, uh, is most

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striking about this gallbladder is something

1:34

that perhaps one can appreciate better on the T2

1:37

weighted, fat-saturated image is that surrounding

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the gallbladder the fat is not hypointense as

1:44

can be seen as normal fat in the subcutaneous

1:47

fat region or anywhere else in the peritoneum. But

1:49

it's quite hyperintense as you scroll downwards.

1:52

This fat is quite hyperintense.

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There are strands of hyperintensity within it

1:57

and all this fluid that's adjacent to the

1:59

gallbladder. This looks like a gallbladder that

2:02

is angry, that is inflamed, and so this finding

2:05

is characteristic of acute cholecystitis.

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I'll show the same findings in the coronal plane.

2:12

You can see that the gallbladder is

2:14

more distended than we would expect.

2:16

It has stones; it has sludge within it.

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Surrounding it, there's all this

2:21

fluid and inflammatory findings.

2:23

And you see this constellation of things,

2:25

including gallbladder wall thickening and edema.

2:28

Gotta be worried about acute cholecystitis.

2:31

Now, as its name would suggest, this is acute

2:32

inflammation of the gallbladder, and the vast

2:35

majority of cases, about 95%, will be due

2:38

to an obstructing stone in the cystic duct.

2:41

A minority of cases may be related to sludge

2:45

that's causing this obstruction, in that

2:47

case we call it acalculous cholecystitis.

2:50

And essentially, the gallstone that we see, or

2:52

the sludge, will cause gallbladder distension,

2:56

doesn't allow the gallbladder to empty.

2:58

That results in bile stasis

3:00

as well within the gallbladder.

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The progressive distension impedes

3:03

venous drainage and lymphatic drainage.

3:07

The bile stasis, in addition to

3:10

that makes the patient at risk for the

3:12

gallbladder becoming superinfected.

3:14

And this results in sort of a cascade

3:16

of reaction where you get wall edema,

3:18

pericholecystic fluid, inflammatory change.

3:23

And as I said, looking at the T2 fat-saturated

3:25

images is key to look for that inflammatory change.

3:27

I think

3:28

you could probably suspect it on the non-fat

3:30

saturated images, but on the fat-saturated

3:32

image it becomes very, very clear that there's

3:34

some abnormality surrounding the gallbladder.

3:37

Typically though, we don't use

3:38

MR to evaluate for cholecystitis.

3:40

Ultrasound and HIDA scan are preferred.

3:42

MRI is often useful to assess the biliary

3:44

tree, to look for choledocholithiasis.

3:47

MRI is also useful to look for complications that

3:50

we will go through in different clinical vignettes.

3:53

And typically when you see something like cholecystitis,

3:57

patients will be taken to surgery.

3:59

If they're not good surgical candidates, they'll

4:00

get a cholecystostomy tube that's placed that

4:04

allows drainage of the gallbladder with eventual

4:07

cholecystectomy when the patient becomes more stable.

4:10

So this here then is a case of

4:11

acute cholecystitis seen on MRI.