0:00

<v ->So we are going to finish up

0:02

with just a few other concepts in this particular segment.

0:07

And that relates to the use of Contrast Agents.

0:12

I'm very proud to indicate

0:14

that the first article that ever was written

0:16

about MR Arthrography came from UCSD.

0:21

I'm the senior author

0:22

but I had little to do with this particular concept.

0:27

And I have to tell you when Mr came along,

0:30

I said, "gee, that's never gonna be important

0:32

to evaluate the musculoskeletal system."

0:35

That's how good I was at predicting things.

0:38

But there were two fellows, MR fellows at UCSD,

0:41

and said, "wait a minute,

0:42

let's try putting Contrast Material in the joint."

0:45

And they did.

0:46

And they in fact, were the brains

0:48

behind this particular procedure

0:50

of direct MR Arthrography.

0:53

Now, when this happened,

0:54

I was told by many of my bone radiologist friends

0:59

that you're turning MR, a non-invasive procedure

1:03

into an invasive procedure.

1:05

This will never catch on.

1:07

And I know there are practices

1:08

where very little MR Arthrography is done

1:11

and there are practices where a lot of it is done.

1:14

We're in between, okay.

1:16

Maybe a little closer to too much MR Arthrography,

1:20

but if there's anyone who says

1:21

it doesn't produce additional information,

1:23

that is incorrect.

1:25

There are times where this can be very, very helpful.

1:28

In our practice, the two most common indications

1:31

for MR Arthrography relate to the assessment

1:35

of the glenohumeral joint labrum,

1:38

trying to separate out a number of conditions

1:41

that can involve the labrum.

1:43

And also, so for slap lesions

1:45

which certainly involve the superior portion of the labrum

1:48

and sometimes other quadrants as well.

1:50

And the second main indication for us

1:53

is the assessment of the labrum of the hip.

1:57

Now we do use it occasionally in the wrist.

1:59

We use it in knees sometimes,

2:01

looking at the articular cartilage

2:04

or evaluating osteochondritis dissecans about the knee.

2:08

We occasionally might use it for searching

2:10

for intraarticular bodies,

2:12

but the two most common places we use it shown there.

2:17

The second way we might use gadolinium

2:20

is to study tumors, or infections, or arthritis.

2:27

And we would inject the gadolinium

2:29

in an intravenous fashion.

2:31

And here we would end up with two particular phases.

2:34

Once you inject the gadolinium, the first phase,

2:38

it isolates into the synovial membrane, turns it bright.

2:41

And then over a period of time

2:43

that contrast is leaked into the joint cavity.

2:46

You have really an indirect MR Arthrography.

2:50

Based on the literature,

2:51

the suggestion is that synovial analysis

2:54

is best within five minutes

2:56

following a bolus intravenous injection,

3:00

and that dynamic investigation of the degree

3:05

and rapidity of enhancement,

3:07

is more important than static analysis

3:10

of synovial enhancement.

3:12

But we will occasionally use it to study synovitis.

3:16

Now, one might argue,

3:17

well does it really give you more information

3:20

than the fluid sensitive sequences?

3:22

And sometimes the results of those two tests are concurred.

3:26

Here is a T2 weighted image where the lot of high signal

3:30

could be fluid or synovium with intravenous gadolinium

3:33

and almost looks the same.

3:35

So most of what we were seeing was in fact synovitis.

3:39

But here's an example where this looks bright.

3:42

Is it fluid or is it synovitis and falling gadolinium,

3:47

no enhancement or virtually none.

3:49

So all of this was joint fluid without synovitis.

3:52

So it does add specificity when compared

3:56

to the T2 weighted images.

3:58

Just to show you a couple of examples,

4:00

here an example of rheumatoid arthritis,

4:03

it's kind of an instructive example because it points out

4:07

that when you're dealing with ankle disease

4:10

that can be normal communication

4:12

with the posterior subtalar joint in 20% of persons.

4:16

And if you have pathology in the ankle joint

4:19

with elevation of intraarticular pressure,

4:22

that percentage goes up.

4:24

So you may have disease in both joints.

4:26

I'm gonna show you an example of that in another disease

4:29

later in this course.

4:31

It also points out that you can have communication

4:34

of the ankle joint with some tendons,

4:36

particularly the flexor hallucis longus tendon,

4:40

but also a occasionally the flexor digitorum longus tendon

4:44

she may communicate with the ankle joint,

4:46

not the tibialis posterior.

4:48

So there is in fact, tenosynovitis in this case as well.

4:54

And then, although we don't use it often

4:56

in cases of adhesive capsulitis

4:59

intravenous gadolinium can in fact be useful.

5:03

There's one article that suggests it can be essential

5:06

in certain instances

5:07

where the fluid sensitive sequences are not diagnostic.

5:12

And with that said, we've reached the stage

5:14

of the second session of case discussion.

5:18

So once again, I turn it over to Rodrigo.

5:21

We're going to talk about that.