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The history here is young female with ankle pain, swelling,

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and decreased range of motion. We have, um,

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sagittal fluid sensitive fat set images, coronal fat set images,

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axial T two and an axial T one set up here. And, um,

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we can start with the sagittal images. Um,

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you can look at the Achilles tendon looks normal.

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We can look at the shape of the Es tendon on axial images.

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As long as the inner surface of the ac least tendon is flat or concave,

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it's okay to not bulge. Um, inside that suggest tendinosis,

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even if the signal is normal. So no achilles, uh, abnormality.

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The signal is uniformly dark, um, no, uh,

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edema, uh, at its insertion or an ified formation. Then the next,

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next structure that we can look at is the plantar fascia. Looks nice, um,

0:59

normal size and signal intensity. And plantar fascia has, uh,

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several bands that we can see on these coronal images. That's the central band,

1:07

that's the lateral band, and that's

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the medial band is here that continues along the planter aspect of the muscles

1:15

of the foot. That's, that's the medial band here.

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The thickest band is the largest, uh, of all,

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and plantar fascist fasciitis typically affects this central band. So this is,

1:27

okay, normal size and signal intensity. Then, uh,

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we can look at the ligaments on axial images. We can start from the top.

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I'm just going through the checklist of how I look at ankle images,

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and we'll see what the findings are. Um,

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the first ligaments that you encounter here are the tibial fibular ligaments,

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the distal tibial fibular ligaments, the anterior and posterior. Now,

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these ligaments course obliquely from tibia to fibular,

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so it's hard to see them as a one continuous band on axial images. Um,

1:58

so you can take the hope of coronal images.

2:01

So this is where your tip ligaments are going to be. See, uh, here,

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so this, these bands here are, you can see the, the,

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the arrangement of the ligament fibers very well here on coronal images.

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So that's your anterior distal tibia fibular ligament looks. Okay.

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And as you go back, this is your interosseous membrane,

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and then this is your posterior distal tibia fibular ligament looks. Okay.

2:29

So the distal tibial fibular ligaments are okay. Then we move down further.

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Now we come to the,

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the lateral ankle ligaments that are at the level of this macular fossa. So, um,

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the f the fibula higher up has flattener surface,

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but as you come more distill at the level of the tails, um,

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it has this concavity, which is known as the macular fossa, and it's,

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it is this level where you look for the tail fibular ligaments.

2:54

So here we have the fbri ligament. I've moved on the image on the left. This is

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Posterior tail of fibular ligament. Again,

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this image image shows the posterior tail of fibular ligament better.

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So these ligaments look okay as we, we move further down,

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what we see is fluid along the posterior aspect of the tail,

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and there is some T two dark soft tissue. We'll come to it later.

3:19

Let's first finish evaluating the ligaments, and then

3:23

the band here that you see arising from the lateral cortex of the calcaneus deep

3:28

to the perennial tendons as your calcan fibular ligament.

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So the lateral ankle ligaments are okay.

3:34

Then moving on to the deltoid ligament. I start on the coronal images.

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So this is, this is your, uh, deep deltoid ligament fibers,

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your tibial tailored ligaments, the interior and the posterior component.

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And then this is the,

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the tibial spring that leads to the SMO band of the spring ligament right there.

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And you can follow this,

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the entire thing forms it as a hammock holding the head of the tails and the

3:59

medial of the foot.

4:00

So deltoid and the SMO band of the spring ligament are okay. From there,

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we will take on to the spring ligament and we'll see the other two.

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So these are the, again, I'm going on the image on the left,

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and these are the two planter bands of the spring ligament. They look okay.

4:18

Then a quick look at the tendons, um, medial tendons.

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There's a mnemonic to remember these, Tom and Harry TBL is posterior, uh,

4:26

flexor digitorum and flexo lysis. And in, along with it is your tarsal.

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This is part of the tarsal tunnel where you have the posterior tibial

4:34

neurovascular bundle.

4:35

And this black band that you see over language is your flexor ulu.

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So as we look at these tendons, these tendons look normal,

4:43

reach towards its normal insertion.

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P posterior inserts has main insertion onto the medial navicular,

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and then other smaller bands to the plantar aspect of other taral bones.

4:54

And then on the lateral side, we have the peroneous, longness and brevis. Um,

4:59

again, as we scroll there along the axial slices, they look okay.

5:03

There is no abnormal signal,

5:04

there is no fluid in the tendon sheet that would suggest tenosynovitis or, um,

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there is no discontinuity that would suggest a tear.

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So brevis inserts onto the base of the fifth and longest will cross over and go

5:16

and insert onto the base of the first metatarsal. So peroneal tendons are okay.

5:21

Medial flexor tendons are okay. Then the anterior are your extensor tendons,

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and here you have TBIs anterior, um,

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extensor lysis and extensia distal tendons. Again, they look okay.

5:36

And that's, that's the band of the extensor at Naum here. That also looks okay.

5:41

Then, uh, looking at the tibial trailer joint,

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all the joints to look for any osteochondral lesions of the ankle really, uh,

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looks okay, the articular cartilage looks okay. The other joints,

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you can look at the, the subular joint,

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that's the posterior FA set of the SubT joint. Looks okay

5:58

Going the other way. So that's your middle of facet of the subtalar joint.

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Talo navicular joint cal oid,

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and then the, the FRA joints. So the, they all, um,

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dar metatarsal joints, they all look, okay,

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we've already looked at Daral tunnel. Um,

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this is your sinus starci or talo calcaneal space.

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It has certain ligaments which look okay. There's slight, uh, edema,

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which is usually an extension of if there's an ankle process going on.

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And then bone marrow looked okay. We didn't see any bone marrow abnormality.

6:34

So really the, the, all the li ligaments, uh, tendons, articular cartilage,

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all look fine. The only abnormality here, um,

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that's what we saw on axial was this, uh,

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soft tissue with posterior tibial Taylor joint effusion and T two high point and

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soft tissue within it. Um, it's signal. This is AT one VI image. Let's see,

6:54

it's signal. So it's, it's intermediate on T one weighted images.

6:58

So when you have in a young patient,

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when you have joint effusion and T two dark, uh, lobulated, uh,

7:04

soft tissue growing within it,

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that would be your diagnostic of nodular synovitis. And it's, uh,

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or they come into the umbrella term of 10 synovial joint cell tumors.

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They can involve the tendon sheath and they can, um,

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that's the synovium of the tendon sheath that they can involve the synovium of

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the joint,

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and that's known as more commonly known as pigmented bi nodular synovitis.

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Now, PBNS can be diffused or it can be localized. Um,

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de depends on like how the growth pattern is.

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And couple important things about PBNS. It's a benign, uh,

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proliferative synovial lesion of uncertain etiology. Nobody knows what happens.

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It's typically monoarticular knee is the,

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we commonly see it around involving the knee, uh,

7:48

PBNS of the knees we commonly see.

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And ankle is the third most commonly affected joint. So after knee,

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it's hip and then ankle. These are the three common joints involved by PBNS.

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And PBNS can occur at any age,

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but it's more commonly seen in the third and fourth decade.

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And the localized form is known as, uh,

8:09

localized nodular synovitis. Now, what do you see on imaging?

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We see multiple intraarticular soft tissue masses,

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which are low signal intensity on T one ated images. And,

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and what this sym this, um, proliferative synovium is, uh,

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hypervascular and it repeatedly bleeds.

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And that's why you get hemosiderin deposition in the synovium and all this

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chronic hemosiderin deposition and the synovium blooms on.

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So if you have any gradient, um, echo image in your sequence,

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you can look at it.

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And if those dark areas look even more darker and more extensive that it's

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suggest that it's blooming, um, artifact created by deposition. So that's,

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that's a diagnostic feature of PVNS and longstanding PVNS,

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though it doesn't affect the articular surface,

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but can cause erosions along the adjacent, um, bone. So, um,

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those features can be seen on radiographs. And the other thing,

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important thing on radiographs is PV NS liver calcified.

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So if you have a lobulated soft tissue mass, um,

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intraarticular with no calcification and it's dark,

9:13

that's when you consider PB NM S two. So, um, some of the,

9:17

what are the differentials of, uh, T two dark, um,

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intraarticular or synovial lesions? First of all,

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one important thing to remember is anytime you have an intraarticular mass,

9:27

one good thing is these are most likely gonna be bi benign, like 99.

9:32

More than 99% of radicular masses are masses are benign.

9:36

With a rare ex sectional, occasionally you'll get test synovial sarcoma or,

9:40

or like that, and within the joint, but typically intra lesions are,

9:45

are benign. So, uh,

9:47

hemophilic arthropathy can give rise to T two dark synovitis because again,

9:51

it's a, it's a,

9:52

it's a process where there is a repeated in raticular hemorrhage,

9:55

but this affects the articular cartilage a lot more. And you see arthritis,

10:00

and then along with it you have T two dark, um, synovitis.

10:04

So if you have a predominantly arthritis process,

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and obviously you'll have the history of patient being a hemophilic and, um,

10:11

disappearance of the joint. So it's, it's hemophilic arthropathy. Another, um,

10:16

cause of T two dark synovial proliferation is dialysis related amyloid

10:20

athropathy, all that amyloid domas are T two dark and they can

10:25

involve, um,

10:26

the synovium of the joint and longstanding ones can cause erosions into the

10:30

bone. So, um, can look very similar like PVNS, but again,

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the clinical presentation is completely different here.

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This is an elderly patient who is a CCK D patient,

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has been on dialysis for a long time,

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whereas all those things doesn't have to be in a, in a patient with PVNS,

10:48

um, chronic tophaceous gout can look similar again, uh, it'll have, uh,

10:53

T two high point. And so now here the soft tissue is very articular.

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It's not intraarticular, and it can cause erosion in adjacent in joints. So,

11:01

um, again, clinical,

11:03

these are usually either in males or elderly females. Um,

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and, um, you predominantly see per articular, um,

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T two hyperintense mass deposition, that's your tophus.

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And that tophus causes adjacent bone erosion,

11:20

but rarely will or involves the joint space late at the disease process.

11:25

So gout would be another differential. And, and, and rheumatoid panis,

11:29

sometimes rheumatoid panis when it's long standing, uh, can have. So this,

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um, here we have this, uh, ankle and joint image axial image.

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You have you looking at the anterior joint space where there is joint diffusion.

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This is AT two pre contrast image, and this is a post contrast image.

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That central T two dark stuff is the fibrotic panis and the peripheral bright

11:52

enhancing

11:53

Part is your hypervascular pans. So synovitis and rheumatoid, um,

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if it's longstanding, it has a fibrotic component can look dark.

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So these are your couple important differential for PV NS. But again,

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if you have in a young patient who presents with joint effusion, um,

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d laing pain, you see, uh,

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joint effusion and those ular T two dark stuff with that blooms on gradient,

12:14

that's, that's diagnostic of PV NS.