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Here is an unfortunate teenager

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with long-standing chronic disease.

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And that chronic disease is Juvenile

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Idiopathic Arthritis, or JIA.

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Uh, and this is a more advanced case.

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On the left image, I have a fat

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suppressed fluid-sensitive sequence.

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The middle image is a T1 fat

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suppressed post-contrast image.

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And on the right is our Dual

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Echo Steady State, or DES.

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Thin, high-resolution images that are great for

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looking at cartilage and cartilaginous surfaces.

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So let's start with the fluid

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sensitive sequence, STR.

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Here we have what looks like a little

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erosion or a geode in the right femoral head.

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We can already tell that the surface of

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that femoral head is very, very irregular.

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There is an effusion, joint effusion.

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And there's almost bone on bone, at

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least what appears to be bone on bone,

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on the coronal images on this side.

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Looking at the other side, we see similar

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areas of erosion, slightly bigger over here.

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You can actually see a little communication

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of that erosion to the joint space.

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Okay.

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Again, a large amount of effusion,

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irregularity, and maybe even a little bit

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of collapse of that right femoral head.

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Looking at the post-contrast images,

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fat suppressed, so everything that's

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bright here is not going to be

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fluid, it's going to be enhancement.

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So what do we have?

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In the region of the effusion, the bright stuff

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is no longer fluid, but it's the synovium

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that's lining the joint that's lighting up.

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So we have synovial enhancement on

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the right side and on the left side.

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And if you look, those areas that we saw cystic

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areas, on the right side, for example, here,

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there's a little bit of misregistration, but

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this corresponds to this right over here.

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That is enhancement, because some of the

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synovium from the joint can invaginate into

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these geodes, or these little cystic structures.

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This is enhancement.

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A secondary finding of osteoarthritis.

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So the juvenile idiopathic arthritis in

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this person has gotten so bad that you're

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now seeing secondary osteoarthritis.

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Because the final common pathway

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of all joint destruction, joint

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inflammation is osteoarthritis.

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And now we're seeing sequelae of

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osteoarthritis even though this is a JIA kid.

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So geode with synovial

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enhancement and invagination.

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You can see something similar

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on this side over here.

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It's not as impressive, but

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you can see it right over here.

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And looking at other parts again, there's

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a little bit of enhancement in the

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subchondral bone, showing that

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there's some synovial enhancement and, and

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invagination in, even in the subchondral area.

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Again, a large amount of effusion that

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is enhancing involving the synovia.

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Looking at our Dual Echo Steady State,

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which is great for looking at cartilage,

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like I mentioned, look at this very

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irregular surface of that femoral head.

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All this is damage to the cartilage.

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Look how little cartilage is left.

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Now, remember this is actually

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two thicknesses of cartilage.

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You have cartilage on the acetabular surface,

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and you have cartilage in the femoral head.

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It should be much thicker than

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this, much smoother, much rounder.

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It has an abnormal appearance both on this side and

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you can really appreciate it on the left side

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where you can see that irregularity coming or

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pooching in with some flattening even of that

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femoral head. The shape of the femoral head is

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also abnormal. It's not as well rounded anymore.

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There's flattening.

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There's a little bit of collapse.

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There is Acetabular Protrusion, meaning that

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a big portion of that femoral head is

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traveling in this direction. Let me just

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show you what I'm talking about with a pen.

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This femoral head has gone in this direction

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into the acetabulum more than it should.

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So it's protruding into the acetabulum.

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So this is a great example of chronic juvenile

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idiopathic arthritis that still shows active

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inflammation, but also shows chronic changes

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such that osteoarthritis has also developed.