0:02

Hello and welcome to Noon Conference, hosted by MRI Online

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Noon Conference connects the global radiology community

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through free live educational webinars that are accessible

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for all and is an opportunity

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to learn alongside top radiologists from around the world.

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We encourage you to ask questions

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and share ideas to help the community learn and grow.

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You can access the recording of today's conference

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and previous noon conferences

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by creating a free MRI online account today.

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We are excited to replay a lecture held in November, 2020

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from Dr. Scott Schiffman, entitled MSK Case Review, followed

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by a live question and answer session with Dr.

0:39

Schiffman. Dr.

0:41

Schiffman completed residency

0:42

and fellowship training at the University of Rochester

0:45

with specialization in MSK imaging.

0:48

Dr. Schiffman is an associate professor at the University

0:51

of Rochester, where his main interests include

0:53

tumor and hip imaging.

0:55

As mentioned, Dr.

0:56

Schiffman will field your questions following the replay.

0:59

Please remember to use the q

1:01

and a feature to submit your questions so we can get to

1:03

as many as we can before our time is up.

1:06

Without further ado, please enjoy this replay

1:08

of MSK case review.

1:11

Alright, um, hello everyone.

1:14

Um, my name is Scott Schiffman

1:16

and, um, an assistant professor of musculoskeletal imaging,

1:19

also fellowship director at the, uh,

1:21

university of Rochester.

1:23

And, uh, today I'm gonna give a presentation on

1:25

MSK case review.

1:27

Here's the first case and, um,

1:29

we'll have a multiple choice question, uh, come up for this.

1:32

Um, so the question is, what is the most likely diagnosis?

1:36

All right, great. So, um, all, all, all

1:38

of the audience members chose ankylosing spondylitis.

1:41

Um, this case is kind of an n mini

1:43

or a slam dunk type of case, um, to show some

1:46

of the imaging findings.

1:47

Um, we have a fusion of the sacroiliac joints bilaterally,

1:51

um, as a sequelae of chronic sacroiliitis.

1:54

Um, we have fusion of the facet joints, um,

1:57

involving the lumbar spine, um, which is producing, um,

2:00

on the AP view, this appearance

2:02

of almost like a tram track abnormality.

2:05

Um, we have, uh, ossification spanning the posterior, um,

2:08

spinous ligaments, um, interspinous ligaments, um,

2:11

which when we see it in the AP view, is, uh,

2:14

producing what's referred to as the dagger sign.

2:16

Um, you know, almost looking like a knife, uh,

2:18

pointed towards the sacrum.

2:20

Um, and we also see, um, a delicate, um,

2:23

bridging CDEs macrophytes, uh, spanning multiple levels

2:26

of the lumbar spine and thoracic spine, um,

2:30

and also squaring of the vertebral bodies.

2:32

You know, normally when you see a lumbar radiograph,

2:34

the vertebral body has a concavity to it,

2:36

and when you wind up with ankylosing spondylitis, um,

2:39

with the syndemic bytes, um,

2:41

and the bridging, it kind

2:42

of squares out the vertebral bodies, um,

2:44

res resulting in an overall appearance,

2:46

which has been described as a, uh, bamboo spine.

2:49

Um, so an important thing to realize about patients

2:52

with this, uh, type of condition, um, is

2:54

that the spine becomes a rigid thing, like a, like a stick

2:57

and a minor trauma,

2:59

whether they might get into a car accident like 20 miles an

3:02

hour, and you have to be aware of the, the possibility

3:05

that they could wind up with a a three column fracture,

3:08

you know, maybe a fracture that goes through the disc

3:10

and also pops out the,

3:11

the spinous process on the other side.

3:13

Um, this type of fracture pattern is a referred to

3:16

as a a chance fracture.

3:20

Um, here's kind of a corollary case to the last one here.

3:23

Um, these are, uh, radiographic findings of sacroiliitis

3:26

where we, um, we see sclerosis on the,

3:29

the sacroiliac joints,

3:31

and we see, um, small erosive changes involving both the

3:34

sacral and iliac sides of, uh,

3:35

bilateral s sacroiliac joints.

3:37

Um, these erosions have been described as looking, um, kind

3:40

of like the edges of a, of a postal stamp, um, when you,

3:44

when you catch multiple of these, uh, small,

3:45

tiny erosions at the joint.

3:47

Um, to give you an idea of

3:48

what this looks like on a CT image, um, you could see that,

3:51

you could see the sclerosis

3:52

and the erosive changes, um,

3:54

centered at the sacroiliac joints.

3:56

Um, so I'll call your attention to the following mnemonic

3:59

of, uh, diseases that could, um, result in sacroiliitis.

4:03

And, um, the important thing to remember of this mnemonic is

4:06

that the, the inner letters, um, for ankylosing spondylitis

4:09

and, um, IBD arthropathy, um,

4:12

these are usually bilateral and symmetric.

4:16

Um, whereas the outer letters of this mnemonic for psoriasis

4:19

and reactive arthritis, um,

4:21

usually are more pronounced on one side than the other.

4:25

Um, so they're somewhat asymmetric,

4:27

although if you let people go long enough

4:28

with the sacroiliitis, they all eventually, uh, start

4:31

to blend together after a while.

4:33

Um, so this is just a useful mnemonic in the,

4:35

in the earlier stages of the sacroiliitis.

4:39

All right. So, um, so moving on to, uh, case number two.

4:42

Um, we have this, uh, hand radiograph

4:44

and also a cropped in, uh, zoomed in version of the finger.

4:47

Um, so we'll have a question that comes up for this case.

4:50

Um, what is the most likely diagnosis? Very great.

4:54

So, um, we've got an audience response.

4:56

The, the majority of people are choosing gout.

4:58

Um, second most popular answer was psoriatic arthritis.

5:01

Um, looking at this case, um, the, the joint

5:04

that we were focusing in on was this, uh, middle finger,

5:06

PIP joint, and you get the sense

5:08

that this might be a monoarticular arthritis in this case,

5:12

um, on the zoomed in version, um, of this joint.

5:15

Um, the key takeaway findings that, um, I wanted you

5:17

to notice is that the, the joint erosion,

5:20

rather than being a marginal joint erosion, um,

5:22

meaning occurring at the, the bare areas.

5:24

So if I draw on the joint capsule right here, um,

5:27

marginal erosions would be occurring at the bare areas

5:29

of the bone at the corners.

5:31

Um, th this erosion is more a para articular, meaning

5:35

that it's just off of the joint level.

5:37

Um, a para articular erosion, um, is more typical

5:40

of a disease like gout.

5:42

Um, the, the other imaging feature

5:44

that's a somewhat pathognomonic is this idea

5:46

of an overhanging edge.

5:48

Um, so when you see an erosion that's para articular,

5:51

and I'm having this overhanging edge,

5:52

like almost looking like a, like a wave is breaking, um,

5:56

this overhanging edge of imaging appearance is also very,

5:59

um, typical of gout.

6:01

Um, the other takeaway is that, um, in,

6:03

in the soft tissue swelling surrounding the joint,

6:05

you could kind of make out faint, uh, calcification, um,

6:08

within the soft tissues, um, suggesting

6:10

that this might be a calcified tophus at this level.

6:13

Um, so, um, I was trying to get ag out with this case.

6:17

Um, and I think, um, fair enough, like when you take, um,

6:20

like maintenance of certification exams

6:22

or board exams, um, obviously they have

6:24

to give you a multiple choice test

6:25

that could include every inflammatory arthritis.

6:27

Um, so the idea is to try to design a question that, um,

6:30

only fits really best with one answer.

6:33

And, you know, that's what I was trying to do

6:35

by highlighting these, these findings.

6:36

Another finding that's, uh,

6:38

somewhat interesting on this patient is this, uh, um,

6:40

SCA illuminate widening compatible with, you know,

6:42

SCA illuminate association in this patient.

6:45

Um, and when you have SCA illuminate association,

6:47

you wind up with a, a volar tilt of the scaphoid

6:50

and dorsal tilted illuminate.

6:52

Um, and you could kind of make that out with,

6:54

with the scaphoid kind of producing this,

6:56

uh, signet ring sign.

6:57

Um, so that's, uh, something to be aware of

6:59

with s scates association.

7:01

You could wind up with a rotary subluxation of the scaphoid.

7:05

Right. I'll, I'll move on to, uh, case number three.

7:08

Um, so we'll, we'll have a question pop up

7:10

for case number three and, you know, try

7:12

to take into account all of the images that are shown.

7:15

Um, for this one, we are also asking

7:17

what is the most likely diagnosis.

7:20

All right, great. So, um, we have, uh, um, the majority

7:23

of the audience has, uh, chosen renal osteo dystrophy

7:26

and, um, that otherwise known

7:27

as secondary hyper parathyroidism.

7:29

And, uh, that is the correct answer.

7:32

Um, the imaging findings that we're showing is, um, the,

7:34

the Ruger jersey spine, um,

7:38

and the other findings

7:39

that would help you put this together, um,

7:40

because, uh, dense, uh, bands of sclerosis at the upper

7:43

and lower end plates of the vertebral bodies can also be

7:45

seen, um, with diseases like osteoporosis.

7:49

Um, so the other findings, uh, to synthesize, um,

7:52

was this idea that you're winding up

7:54

with a sub ligamentous resorption

7:55

of bone at the pubic synthesis

7:58

and sub ligamentous resorption

7:59

of bone at the sacroiliac joint, um, resulting in widening

8:03

of this, uh, sacroiliac joint here.

8:04

You could see some of the erosive changes, um, as we,

8:08

as we go through some of the imaging in this patient, um,

8:11

you know, so here's, um, here's the CT scan.

8:14

Um, we could see the, the rugger jersey spine.

8:17

Um, we could see the, um, erosive changes, um,

8:20

or widening sub ligamentous resorption at

8:22

the sacroiliac joint.

8:24

We could see it occurring at the pubic synthesis.

8:27

And then it shouldn't surprise you

8:28

that this patient's kidneys are completely atrophic.

8:32

Um, this patient was on dialysis.

8:34

Um, so oftentimes if you see a patient with this, uh, severe

8:37

of a rugged jersey spine,

8:38

you'd be expecting their creatinine to be, you know,

8:41

somewhere in the neighborhood of like five to seven, um,

8:43

and A GFR lower than 15 or so.

8:46

Um, so when you see this, this, uh, this amount of, uh, um,

8:50

abnormality here, um, I've also, for this patient, um, just

8:53

to emphasize another point, um, I've also loaded up, uh, one

8:57

of their chest x-rays, um, just to show an area, um,

9:01

where you also get sub ligamentous resorption of bone, um,

9:04

at the caracal clavicular ligament assertion sites

9:07

and at the acromial clavicular ligament, um, um,

9:09

sites you might wind up with widening

9:11

of bilateral acromial clavicular joints.

9:14

Um, this is not post-surgical,

9:15

it's not from like a distal clavicle resection

9:18

and, um, you know, it's not, um, in this case from trauma.

9:22

Um, in this case it's from a resorption of bone related

9:25

to the secondary hyperparathyroidism.

9:27

Um, and similarly, you wind up

9:28

with sub ligamentous resorption

9:29

of bone at the caracal clavicular ligament insertion site,

9:33

um, resulting in kind of like this undersurface scalloping

9:36

of the, uh, distal clavicle.

9:38

Um, so, um, so that's another nice, uh, finding,

9:41

demonstrating, um, findings of, um, renal osteo dystrophy.

9:46

Um, all right, so, um, I'll move on to the next case.

9:50

Um, so we have a, uh, pediatric, uh, pelvis x-ray,

9:55

and I'll also, um, kind of, uh,

9:57

pump in a three dimensional images, uh,

10:00

from the CT scan on this patient.

10:02

And, um, the question is, um,

10:06

what tendon group is responsible for the avulsion fracture?

10:10

So, all great.

10:12

So, um, the, the, the majority of the audience has responded

10:15

with the, uh, hamstringing tendon group, um, which,

10:18

uh, was the correct answer.

10:19

Um, this, uh, this all comes back to the idea of like, uh,

10:23

avulsion fractures of the, uh, pediatric pelvis and hip.

10:26

Um, and, uh, really this comes down to just knowing, um,

10:28

the anatomy of where the tendons are arising

10:30

and when they're, where they're inserting.

10:32

Um, so, um, for the, for the ischial tuberosity, avulsion,

10:36

here's the avulsion fracture right here from

10:37

the ischial tuberosity.

10:39

Um, this is the origin of your,

10:41

of your common hamstring tendon, uh, group.

10:43

Um, so that's the hamstringing tendons.

10:45

Um, the lesser trocanter is the insertion site

10:48

of your ilio os tendon.

10:51

Um, so that would be, if, if this was a vols,

10:53

that would be your ilio os.

10:55

Um, the greater trocanter is where your gluteus mi minimus

10:58

and gluteus medias are inserting.

11:00

Um, so this would be, if your greater trocanter was AULs,

11:03

this would be your, your gluteal tendons.

11:06

Um, and then the two sites on the pelvis

11:07

that are most commonly injured, um,

11:09

one would be your anterior inferior iliac spine.

11:13

Um, this is, uh, where the rectus femoris is arising from,

11:16

um, and then your anterior superior iliac spine, um,

11:20

which is where your sartorius is arising from.

11:23

Um, so just having a nice, uh, um, ability of remembering

11:27

where these tendons are arising

11:28

or where they're inserting, um, will help you, um, with,

11:31

with regards to what might be causing the evulsion fracture.

11:35

Um, uh, here's an example of this patient's, uh, CT scan.

11:39

Um, so you'll notice that when I get

11:41

to the ischial tuberosity right here, um, you'll notice

11:44

that this piece of bone is completely pulled off of, um, um,

11:48

of the, uh, hypothesis.

11:49

It's distracted. Um,

11:51

and if we had an MRI, we would see

11:53

that this is still attached to the, uh,

11:55

to the hamstring tendons.

11:57

Um, so this is just, uh,

11:58

basically an avulsion fracture at this location.

12:01

All right. So, um, I'll, I'll advance the slide one more

12:04

and we'll move on to, uh, case number five, right.

12:07

So, um, ca case number five, um, I have the question.

12:11

Um, so look at the images, try to figure out

12:13

what the diagnosis might be,

12:15

and then try to figure out

12:16

what relevant clinical history would support the diagnosis.

12:20

Um, what relevant clinical history would help

12:22

support the diagnosis?

12:24

All right, great. Um, again, the, the majority

12:26

of the audience has gone with a longstanding bisphosphonate

12:30

treatment for osteoporosis.

12:32

Um, and that is the correct answer.

12:35

Um, what I was trying to get at in this case is, um,

12:37

we have an abnormality, um,

12:39

which is centered at the subter region

12:41

of the proximal femur,

12:43

and the abnormality is basically an insufficiency fracture.

12:46

Um, we see, um, end osteo marrow edema on this side,

12:50

and we see periosteal edema on this side.

12:53

And then the intervening cortex, um, is showing, um, um,

12:56

you can't make it out on this, uh,

12:58

T two weighted image, uh, with fats out.

13:00

Um, but this would've been an intracortical fracture, um,

13:03

a similar patient on the plane film.

13:05

Um, you could kind of make that linear lucency

13:07

that's running through the cortex, um, oriented in,

13:10

in a horizontal direction, um, forming

13:12

what looks almost like a volcano, um, in this direction.

13:15

You can imagine magma kind of like spewing out

13:18

of the volcano in this direction.

13:20

Um, and the reason that it looks like a volcano is

13:22

because not only do you have this fracture,

13:23

but you have this periosteal thickening, um,

13:25

which helps produce kind of this, uh,

13:27

volcano, uh, type of look.

13:29

Um, so when you have an insufficiency fracture

13:32

of your lateral subter femur, um, this has been noticed

13:36

to be occurring in patients that are taking medications such

13:39

as bisphosphonates, um,

13:41

or even, um, medications, uh, um, like X-G-E-V-A, um,

13:46

like medications that are used to try

13:48

to increase boney density.

13:49

Um, and it leads to altered, um, biomechanics

13:53

and altered, um, weak points of the bone

13:55

or str strong points of the bone.

13:57

And instead of, uh, you know, the

13:58

nor normal sites of stress fractures might be at the femoral

14:01

neck, um,

14:02

but when these patients are on this medication

14:04

for a long time, they develop new weak points of the bone.

14:07

And, and this is a, this is what's referred to

14:09

as an atypical femur fracture.

14:11

Um, so if this progresses through the shaft of the femur

14:13

and the patient came into the ed,

14:15

this would be an atypical femur fracture, not your usual run

14:18

of the mill femur fracture.

14:19

Um, and that has been noticed to be associated with, uh,

14:22

bisphosphonates, um, the,

14:26

the MRI in this patient.

14:27

Um, um, to give you an idea of what this looks like,

14:32

um, here's a coronal view of the, of the pelvis.

14:36

Um, you can see that it's, at the moment, it's isolated to,

14:38

um, to this left hip.

14:40

Um, and when I go to an axial projection, you could kind

14:45

of make out, um, the findings of a stress fracture

14:48

that you would encounter elsewhere, um, in the body, um,

14:51

which is, um,

14:52

and these are graded based on, um,

14:54

if you're seeing end osteo edema, periosteal edema.

14:58

Um, any signs of a cortical fracture

15:00

or any marrow edema, um, would help you kind of, uh, um,

15:04

classify what stage, um, of a,

15:06

of a stress injury you're dealing with

15:08

or insufficiency fracture in this, uh, in this case.

15:11

Um, and then the most common way

15:13

that these have been treated is, uh,

15:15

with a prophylactic fixation.

15:17

Um, so they might put an intramedullary, um, nail

15:20

or celo medullary nail to kind of stabilize the hip

15:23

and prevent this from progressing, um,

15:25

or they might have the patient try

15:26

to do a non-weight bearing,

15:28

or they might stop the medication.

15:29

Um, but something to keep in mind about the hip, which is,

15:32

uh, somewhat unique is, um,

15:34

because the hip is, uh, somewhat curved like, like a cane,

15:37

um, it produces a side of, uh, compressive forces

15:40

and a side of tensile forces.

15:42

And in general, um, stress fractures tend to occur,

15:47

um, on this, uh, compressive side

15:49

of the femoral neck in which it's held in compression.

15:51

And you imagine that with enough non-weightbearing,

15:54

the stress fracture might heal.

15:56

The problem with this stress fracture is it's more on the

15:58

tensile side of the hip,

16:00

and when you're on the tensile side of the hip,

16:01

then you have more difficulty with healing.

16:04

Um, so maybe that's the rationale behind, uh,

16:06

doing the prophylactic fixation.

16:09

Um, all right, so, um, we'll move on to,

16:11

uh, case number six.

16:13

Um, um, case number six.

16:15

Uh, here's the, uh, pelvis image on, on a patient.

16:19

Um, and I'm, I'm gonna have a mystery image pop up in the

16:22

future and, uh, you know, try

16:24

to synthesize all the information in

16:26

this, uh, in this study.

16:27

Um, even parts of the lumbar spine are in there, um,

16:30

but I wanna see if you could make the most likely diagnosis

16:33

based on this, uh, pelvis, uh, radiograph.

16:36

All right, great. So, um, the majority of, uh, um,

16:39

answers went with a sickle cell disease.

16:41

That is the correct answer.

16:43

Um, uh, the, the things to realize on this, uh, pelvis, uh,

16:46

radiograph is that, um, there's multiple areas

16:48

of osteonecrosis, um, including avascular necrosis

16:52

of this hip with flattening of the femoral head

16:54

and severe degenerative disease.

16:56

Um, you have, uh, you know, serpiginous areas

16:58

of sclerosis involving the femoral heads, um,

17:01

which could be areas of either bone infarcts or AAV n

17:04

and similar findings in the pelvis.

17:06

Um, the findings in the spine that I was trying

17:08

to highlight, um,

17:09

and I'll bring it in on, on this next image, uh, here, um,

17:13

is this idea, um, and this is the patient's, a CT

17:15

of their thoracic spine, is this idea of these, uh,

17:18

h shaped, uh, vertebral bodies

17:20

or fish mouth shaped vertebral bodies, where

17:22

because of the, uh, chronic ischemia, you wind up

17:25

with depression of the superior

17:27

and inferior end plates, um, in patients

17:29

with sickle cell disease,

17:31

and you wind up with these vertebral bodies that are, um,

17:33

having this, uh, h uh, shaped to them.

17:35

Um, you might be able to make out some subtle abnormalities

17:38

on this, on this plain film right here.

17:40

Um, to give you an idea of what this looked like on,

17:42

on the patient's CT scan, um, as we're panning through,

17:46

you can see all the bones are sclerotic.

17:48

And then when you get to like your midsagittal aspect,

17:51

you can see, um, you know, the, the typical hha uh,

17:55

vertebral bodies throughout basically the

17:57

entire thoracic spine.

17:59

Um, another finding that this patient had that goes nicely

18:01

with the sickle cell disease, um, was, uh, included on this,

18:05

uh, um, thoracic spine CT was kind of a small spleen.

18:10

Um, so that would also go with the idea

18:11

of sickle cell disease.

18:13

Um, so the musculoskeletal manifestations in sickle cell is

18:16

usually, um, osteonecrosis of multiple bones, um,

18:20

but another manifestation might be osteomyelitis.

18:23

And then it's just important to remember this idea that,

18:26

you know, most common is still staph aureus,

18:28

but, um, people with sickle cell disease can also get, um,

18:32

um, um, osteomyelitis from, um, um,

18:36

from other organisms that are, um, unusual in normal people,

18:40

um, such as salmonella.

18:42

All right. So, um, moving on to, um,

18:45

moving on to case number seven.

18:47

Um, so case number seven, the question is,

18:50

what is the most likely diagnosis?

18:53

All right, so, um, a hundred percent of the people

18:56

that responded, uh, landed with the right diagnosis,

18:58

which was erosive osteoarthritis.

19:00

Um, this is like one

19:01

of the best examples I could find of this.

19:04

Um, but the idea with, uh, erosive osteoarthritis is

19:07

that it takes on the same joints that normally get involved

19:10

by osteoarthritis.

19:12

Um, that means that the DIP joints are affected,

19:14

the PIP joints are affected,

19:16

and the basal joint is affected.

19:18

Um, but to distinguish it from osteoarthritis, um,

19:21

the finding that we're looking

19:22

for is what's called central erosions.

19:24

Um, so to, to demonstrate what this looks like, um,

19:27

I'm gonna demonstrate it on this more normal looking joint,

19:30

a central erosion, um, of this, uh, base

19:32

of the phalanx here would be, um,

19:35

a a central erosion occurring right here,

19:38

a central erosion occurring right here,

19:40

and a central erosion involving the head looking like this.

19:43

And when you, when you combine these three central erosions,

19:46

you wind up producing what's referred to

19:48

as a seagull deformity, um, where the base

19:50

of the di the distal phalanx in this case, um,

19:53

if I outlined it, it kinda looks like, like a seagull, um,

19:56

you know, doing its, uh, flying motion.

19:59

Um, so this is what's meant by the, the gull wing deformity,

20:02

and this is what's meant by the central erosive changes, um,

20:05

of erosive osteoarthritis.

20:09

Um, so, um, yeah, very good response rate

20:11

by the audience on this question.

20:13

And, um, the way to distinguish this from other arthritis

20:15

is, um, you know, you know,

20:16

rheumatoid arthritis more typically involving the proximal

20:19

joints like CPS

20:20

and the wrist, um, usually with marginal erosions.

20:23

Um, and I think psoriasis is a good alternative

20:26

diagnosis in a case like this.

20:28

Um, but this is so classic of erosive osteoarthritis

20:30

with the osteophytes, um,

20:32

and also the central erosions joints based narrowing.

20:34

It just, uh, fits too well with erosive osteoarthritis.

20:38

Psoriasis, you will get some marginal erosions,

20:40

and you'll get also a peros titis

20:43

and sometimes even a sausage finger.

20:45

Um, so those are some, uh, pearls for, uh, psoriasis.

20:49

All right. Um, next case.

20:52

Um, so we have an MRI of the shoulder, um,

20:55

and the case is, the question is

20:58

what is the most likely etiology of this imaging finding?

21:01

All right, great. Um, the, the majority of the audience, uh,

21:03

landed on infection or inflammation,

21:06

and, uh, that is the, that is the correct answer.

21:10

Um, what we're looking at actually is, uh, the term

21:13

of this is called rice bodies, um,

21:16

and, uh, rice bodies, um,

21:18

so we have basically subacromial subdeltoid bursitis,

21:21

and it's filled with all of these, uh, these small, um,

21:24

synovial fragments that are shaped like grains of rice.

21:27

Um, basically the rice bodies is from either chronic

21:30

inflammation or chronic infection.

21:32

Um, the most typical candidates is rheumatoid arthritis

21:35

or even tuberculosis.

21:37

Those are the most common,

21:38

or even something like synovial chondro mitosis.

21:41

Um, you wind up with pieces of synovium infarct

21:44

and falling off into the joint.

21:45

Um, and then when they fall off into the joint, they kind

21:47

of produce all these little grains of rice, um,

21:50

within this case, the bursa.

21:52

Um, what this patient looked like, if you were to, um,

21:55

look at this on an MRI, um, here as I'm, as I'm scrolling

21:59

through, um, you could see that this,

22:02

this bursa is just filled with numerous, uh, small bodies.

22:06

Um, when I, when I kind of do it on the sagittal plane here,

22:09

um, you can see that it's filled with numerous tiny, uh,

22:11

small, uh, bodies within the bursal fluid collection, um,

22:14

compatible with those rice bodies.

22:17

Um, one way to distinguish this from, say,

22:18

like lipoma AEs essence is on a T one weighted sequence,

22:22

you'd expect the lipoma AEs essence to have, um,

22:25

fat signal intensity.

22:27

Um, so it, it, these,

22:29

these nodules should be bright on a T one sequence if there

22:31

were really frons of fat.

22:33

Um, so yeah, just to have in the back of your mind this idea

22:36

of rice bodies, and probably the two most important

22:39

differentials to know is rheumatoid arthritis

22:41

and tuberculosis,

22:42

but this could be seen with any longstanding inflammatory

22:45

or infectious arthritis, um, given the right circumstances.

22:49

Um, all right, so I'm going to move on

22:51

to question number nine.

22:53

Um, and you'll notice that, um, um,

22:56

even though the patient does have a scaphoid fracture,

22:58

you'll notice that that is not one

23:00

of the choices, uh, for this question.

23:02

Um, so you want to go a little bit bit beyond that.

23:05

Um, question number nine is, what is the primary diagnosis?

23:10

All right, great. Um, the majority

23:11

of the audience also got the answer right?

23:12

It, the answer was a peri lunate dislocation.

23:15

Um, this gets down to the crux of, um, the orientation

23:19

of the, of the bones on the lateral projection.

23:22

Um, so here we could tell that the position

23:24

of the lunate on this AP view is just completely abnormal.

23:27

It's even overlapping the capitate and the hammit.

23:29

I'm not quite producing that pie in the sky appearance.

23:32

That's very, very typical.

23:33

But we could tell that this appearance

23:35

is just completely abnormal.

23:37

Um, when we go to the lateral view, um, we could see, um,

23:40

the distal radius right here.

23:43

We could see the lunate, um, right here,

23:46

and we can see that, um, the alignment of the radius

23:48

with the lunate is still maintained.

23:50

Um, so if I draw the line down the radius

23:52

through the lunate, um, the, the orientation

23:55

of these two bones is still maintained.

23:57

Um, however, if we try to find the capitate in this case,

24:00

um, the capitate may be,

24:01

and it might be the shadow, um, back here, um, we can tell

24:05

that the capitate is basically dorsally

24:07

dislocated relative to the lunate.

24:10

Um, so when the dislocation happens at the joint

24:12

between the lunate and the capitate, and the radius

24:14

and the lunate are still aligned, um,

24:16

this is what's referred to as a peri lunate dislocation.

24:20

If the radius was still aligned with the capitate

24:23

and the lunate was dislocated,

24:24

and there's no more alignment with the radius

24:26

and the lunate, um, that's what's referred to

24:28

as a lunate dislocation.

24:30

Um, when this, uh, when this peri lunate dislocation occurs,

24:33

um, oftentimes it occurs wi with additional fractures,

24:36

sometimes involving the scaphoid,

24:38

sometimes involving the triquetrum.

24:41

And then the most appropriate terminology for this type

24:43

of a pattern, um, would be

24:45

that this is a trans scaphoid per illuminate

24:48

dis dislocation.

24:50

Um, so that would be the most accurate way of, uh,

24:52

of wording such a report, um, possibly even trans scaphoid,

24:56

trans triquetral, um, per illuminate dislocation.

25:00

Um, here's a corollary case, not to come with questions,

25:03

but, um, here we could see

25:05

that the distal radius is right here.

25:07

Um, we could see that the capitate is right here.

25:10

Um, so we could see that the orientation of the radius

25:12

and the capitate is maintained.

25:14

Um, but in this case, we could see that the lunate, um, um,

25:17

is, uh, no longer in the patient's wrist anymore.

25:21

Um, basically a significant amount

25:22

of forces popped this lunate out vol, you could see it kind

25:26

of even super projecting over the radius in this view, um,

25:29

producing this strange looking, uh, empty space right here.

25:32

Um, and, uh, one point I wanna make,

25:34

and this is true for most dislocations, um,

25:36

throughout the M mss K system, um, for the lunate

25:39

to get this far away from where it should be, um, you have

25:42

to know that the sca of lunate ligament

25:44

and the lunar triquetral ligament, um, both have to be torn.

25:47

Um, they can no longer still be attached to the lunate

25:49

for the lunate to basically dislocate like this.

25:52

And, you know, think about this,

25:53

when you're seeing other dislocations around the body,

25:56

you know, if you had like a posterior knee dislocation

25:58

that would tell you that probably, um,

26:01

your posterior cruciate ligament can no longer be intact,

26:04

you know, et cetera.

26:06

Um, so just always think that, you know,

26:08

ligaments are kind of holding the joint together.

26:10

Um, so to get such a massive dislocation,

26:12

ligaments do have to be damaged.

26:14

All right, so, um, moving on to, uh, case number 10.

26:17

So case number 10, we're asking what is the diagnosis?

26:21

All right, so I'm just checking the audience responses.

26:24

All right, great. So the audience was torn between the, uh,

26:26

Taylor Calcan Coalition

26:28

and the Calcan Navicular Coalition with Oh, I see

26:31

with the majority going with the Calcan Navicular Coalition,

26:34

except, uh, um, I, I had a, uh,

26:36

a spelling error in my, in my question.

26:38

So it accidentally said, tale Navicular Coalition.

26:41

Sorry about that. Um,

26:42

but yeah, the answer in this question was Calcan

26:44

Navicular Coalition.

26:46

Um, and the, the key takeaway is that the,

26:48

the anterior process of the calcaneus here, um, is kind

26:51

of blending in, um, towards the direction of the navicular.

26:54

You can't really make out where it's ending.

26:56

Um, this phenomenon

26:57

where you get this stretched out appearance

26:59

of the anterior process of the calcaneus is what's referred

27:02

to as an anteater sign.

27:03

Um, 'cause it kind of looks like an anteater's nose.

27:06

Um, then when you look at this oblique view of the foot,

27:09

you could kind of make out this, uh,

27:10

bony connection that's occurring.

27:12

Um, between, here's the, here's the outline of

27:14

what I would think is the navicular bone right here.

27:16

Um, and you see this bony bridge forming

27:18

between the calcaneus and the navicular.

27:21

Um, this patient, uh, to show you what this looks like on a,

27:24

on a CT image, um,

27:26

here's a 3D reconstruction from the patient's, uh, CT scan.

27:30

And you see as I kind of march around

27:32

and, uh, rotate this patient's foot, um,

27:35

you could see this bony bridge

27:36

that's completely fused the anterior process

27:38

of the calcaneus with the navicular.

27:40

Um, um, so this is, uh,

27:42

what a calcan navicular coalition will look like

27:45

on, on radiographs.

27:47

Um, now the Taylor Calcan Coalition,

27:49

which I'll show on the next slide as the corollary case, um,

27:52

something to focus on is, um, this, this medial aspect

27:56

of the calcaneus referred to

27:57

as the Sust tenaculum tail eye is located at this location,

28:02

and then the medial poster medial aspect

28:04

of the tails is located at this location looking like this.

28:07

Um, if you have this space that's in between these, uh,

28:10

two bones, um, this, this is, this is the space

28:14

that will let you know that most likely there's not

28:16

a coalition occurring.

28:17

If this space gets lost, um, then that's a sign

28:20

that tells you to look for a Talo calcaneal coalition.

28:23

Um, so for example, when I move to this next case, um,

28:26

we could see that that space

28:27

that I previously showed is just completely obliterated, um,

28:30

and the bones look completely fused.

28:33

And the sign for this finding

28:35

is what's referred to as a C sign.

28:38

So if I outline the Alis

28:40

and I kind of extended, um,

28:41

towards the sustin talum tail eye,

28:44

it forms a continuous c uh, on the lateral view, um,

28:48

because the bones have, uh, fused

28:49

and not produced that gap that we were seeing before.

28:52

Um, so this is what's referred to

28:53

as a Telo Calcan Coalition on MRI.

28:56

It looks like this. Um,

28:58

here's your suta tail eye right here.

29:00

Um, normally there's a gap between that and the ali,

29:03

and here we see just complete, uh, bony continuity across,

29:06

across this side of the Telo Calcaneal Coalition.

29:10

Um, something to keep in mind is like, what,

29:12

what would be the indication for such a study like this?

29:15

Um, usually these people, um, have what's referred to

29:18

as a rigid pest planus, um, meaning that whether

29:21

or not they're weightbearing or non-weight-bearing, um,

29:24

in general, they have, uh, some form of a pest planus.

29:27

Um, whereas, uh, adult patients that don't have a coalition,

29:30

you know, the most common cause

29:31

of pess planus might be a posterior tibial tendon tear.

29:34

Um, but in those adult patients,

29:36

it's no longer a rigid pess planus.

29:38

It's what's referred to as a flexible pess planus

29:40

where it's worse on weight bearing than

29:42

it is on non-weight bearing.

29:44

Um, so is that something

29:45

to keep in mind if an orthopedic surgeon, you know,

29:48

if they're thinking that the patient might have a rigid hind

29:50

foot, um, you know, they might do some advanced imaging

29:53

to look for these coalitions

29:55

and the relative distribution between these two, you know,

29:58

they're more or less equal.

29:59

I think it's almost like 49%, 49%, 49, 40 8%.

30:03

It's almost like the presidential election or something.

30:06

Um, so I think it would be unfair to,

30:08

to ask a question like,

30:09

what's the most common Hein foot coalition?

30:11

I think that that would be a little bit mean. Um, all right.

30:15

So, um, moving on to, uh, case number 11.

30:19

Um, so case number 11, the question is

30:22

what soft tissue injury is commonly associated

30:25

with this imaging finding?

30:27

All right, great. So, um, the majority

30:28

of the audience has responded that the answer was, uh,

30:30

anterior cruciate ligament tear,

30:32

and, uh, that is the correct answer.

30:35

Um, what we're showing here is what's referred to

30:37

as a sigon fracture.

30:39

Um, so a sigon fracture, you know, has an EpiPen.

30:42

Um, and this is basically an avulsion fracture

30:44

of the lateral rim of the, of the, uh,

30:47

lateral tibial plateau.

30:49

Um, and there's all sorts of debates as to

30:51

what causes this avulsion fracture.

30:53

Um, the avulsion is actually occurring between, um, between

30:57

where the iliotibial band is inserting on the, on the,

31:00

on the proximal tibia and in between the level of the LCL.

31:04

Um, so it's occurring somewhere

31:05

between the anterior mid aspects

31:07

and some anatomists feel like they've discovered a new

31:09

ligament of the knee, which they've, uh, called the, um,

31:12

anterolateral ligament, the a LL, um,

31:16

and they think that this might be the culprit for

31:18

what produces the segun fracture.

31:20

Um, but needless to say, if you,

31:21

if you saw this come up on a test, I think probably the,

31:25

the appropriate answer is still to call it like a lateral,

31:27

um, capsular avulsion, um, if you wanted to go that way.

31:32

Um, this patient's, uh, knee MRI, um, so here, I'll,

31:36

I'll advance the image one, um,

31:38

and then I'll, I'll open up the,

31:40

the knee MRI in this, in this patient's case.

31:42

Um, so the thing

31:43

to realize about the segun fracture is has a very strong

31:46

association with an ACL tear.

31:48

Um, probably seen in like 70

31:50

or 80% of cases that have the sigon fracture

31:53

and that that's the most common association.

31:56

Um, so you could tell that this patient,

31:57

while we do make out the distal tibial insertion of the ACL,

32:00

um, the mid portion of the ACL looks like

32:02

an explosion has occurred.

32:04

And if there was any question about whether

32:05

or not this represented an ACL tear, um, you could kind

32:08

of go off midline

32:10

and see these, uh, kissing contusion pattern, um,

32:13

with the contusion involving the posterolateral tibial

32:15

plateau and this anterior to mid aspect

32:18

of the lateral femoral condyle.

32:20

Um, the idea being is that when you, when you tear your ACL,

32:24

you temporarily have kind of like a pivot shift

32:26

or buckling type of injury

32:27

where your tibial will slide forward, um, impact

32:30

with this portion of the femoral condyle

32:32

and then kind of reset itself.

32:34

Um, so, um, so that's, uh, how to explain these, uh,

32:37

kissing contusions, um, with the,

32:39

with the ACL, um, fracture pattern.

32:42

And then of course, when you see a segun fracture, you know,

32:44

you're dealing with injury to the

32:45

lateral aspect of the knee.

32:47

Um, so that means that you should pay more attention

32:49

to the posterolateral corner of the knee.

32:51

Um, I just wanna show some idea, an idea of what, um,

32:56

when you have an avulsion fracture in the M MSS K system,

32:58

sometimes these can be difficult to identify on an MRI

33:01

because the bony fragment is so small that, um,

33:05

when you get a fat saturated sequence, not all

33:08

of the time will you see something emus like this.

33:10

Um, um, a lot of the time it'll be fat saturated

33:13

and you won't be able to make out the avulsion fracture.

33:15

Um, so my recommendation is this is the area

33:18

to use your T one sequences, um,

33:20

to make out this small bony fragment that is vols.

33:23

Um, all right, so, um, that being said, I, I'll move on

33:27

to the next case, um, so that we could kind

33:29

of maximize the amount of cases you get to see.

33:32

Um, so, um, this is a case number 12,

33:37

and the question is, what is the most likely diagnosis?

33:41

All right, great. Um, we, we have a very strong response

33:43

from the audience with a hundred percent of people choosing

33:46

aneurysmal bone cyst.

33:47

Um, luckily I didn't put like a differential including

33:50

telan, ticos osteosarcoma in the question,

33:52

which would've been mean I think.

33:54

Um, but we could see on this radiograph,

33:55

we have a loosen lesion in the, um, intr enteric region

33:59

of the proximal femur.

34:00

We can make out some subtle, uh,

34:02

internal trabeculation within the lesion

34:04

and maybe a geographic one, a border around the lesion.

34:08

Um, when we get the MRI on the patient,

34:10

we see multiple blood blood levels

34:12

or fluid fluid levels within the lesion, um, separated by,

34:15

um, these internal trabeculation.

34:18

And when we give contrast, we could see the only things

34:20

that are enhancing in this lesion is the periphery

34:23

of the lesion and also the periphery of all these little,

34:25

um, pockets of the lesion that's created

34:27

by the internal trabeculations.

34:30

Um, the, the differential when you see multiple fluid,

34:33

fluid levels involving a bony lesion is basically primary

34:37

or secondary aneurysmal bone cyst or telan osteosarcoma.

34:42

Um, so you'd wanna really scrutinize this radiograph

34:45

to see if there's any areas of osteoid deposition, you

34:48

or osteoid matrix,

34:50

and you'd really wanna scrutinize the MRI image

34:52

to see if there's any areas of nodular enhancement

34:55

or mass like enhancement, which might tell you

34:57

that you're dealing with a secondary A, B, C or lant.

35:01

Osteosarcoma. Um, th this patient, uh, did have some, uh,

35:05

edema surrounding the bone, which may have been related

35:07

to like a stress.

35:09

Um, there may have been like a non-displaced, uh,

35:11

insufficiency fracture associated with this lesion.

35:14

Um, also this patient has a, a finding,

35:17

which you might encounter on some hip MRIs, um,

35:20

where you have kind of this, uh, adventitial bursitis, uh,

35:23

occurring between the lesser trocanter in the, uh,

35:25

ischial tuberosity.

35:27

And you have narrowing of this, uh, interval

35:29

between the ischial tuberosity and the lesser tro canter.

35:32

Um, so if you see this in a, in a sports medicine type case,

35:35

um, this would be referred to

35:37

as a ischial femoral impingement, um, where you wind up

35:40

with the edema involving your quadratus, uh, femoral muscle,

35:43

um, or you wind up with this adventitial

35:45

bursitis at this location.

35:47

Um, to give you an idea of what this, uh,

35:49

patient's imaging looked like on, on the MRI, um,

35:52

although I think it's fairly covered already, um, um,

35:55

in this case, but what, what I like about these cases

35:57

with the aneurysmal bone cyst is the, the way that these,

36:00

uh, blood fluid levels

36:01

or fluid fluid levels, um, precipitate, um,

36:04

tells you the direction that the

36:05

patient was laying on the table.

36:07

Um, so the patient was laying on the table, you know,

36:09

with gravity, pulling things down in this direction.

36:11

You know, if you were to somehow be able

36:13

to scan someone sideways, you know,

36:15

where they were laying on the lateral aspect of their hip,

36:17

then you'd expect these fluid levels, um,

36:19

to occur in the other direction.

36:21

Um, and you can make out this nice, uh,

36:23

geographic one a margin of the lesion, um, which, uh,

36:27

points out that it's, uh, more likely

36:28

to be a benign etiology.

36:30

Um, and then when we go to our, um, pre

36:33

and post contrast images, uh, I'll point out, uh, here's

36:36

what it looks like on the pre contrast

36:38

and on the post contrast.

36:39

Again, um, just this thin peripheral enhancement on all

36:43

these LOEs, um, which were re, uh, separated

36:46

by those internal trabeculations, um,

36:48

but no areas where we're seeing nodular mass

36:51

like enhancement in this case.

36:53

Um, one, one pearl, if you want any pearls for, um,

36:57

for these, uh, findings when you have internal trabeculation

36:59

with an lytic lesion like this, um, a mnemonic that I like

37:02

to use is, is, is this idea of, uh, a change.

37:06

Um, so, um, changed like this.

37:09

Um, so if you see these, uh, internal trabeculations, um,

37:13

you wind up with things like chondro mix site fibroma, um,

37:17

aneurysmal bone cyst, non ossifying fibroma,

37:19

giant cell tumor, et cetera, desmoplastic fibroma.

37:22

Um, but when you wind up

37:23

with this plus these fluid fluid levels,

37:25

you've basically narrowed down your differential two either

37:27

A, B, C or maybe something causing a secondary A, B, C.

37:31

Um, so you're basically narrowed down your differential

37:33

to these, to these middle, uh, categories here.

37:37

Um, this, this is a corollary case.

37:39

Um, this is a pediatric patient.

37:41

They also have a loosened lesion involving the proximal

37:44

humerus with a pathologic fracture.

37:46

And this is an on mini

37:47

because, um, we, we could see the, we have what's referred

37:50

to as the fallen fragment sign.

37:52

Um, what a fallen fragment sign is, is a piece of cortex

37:55

that is broken off from the fracture

37:57

and has gone into the cyst

37:58

and fallen into the, uh, dependent portion of the cyst.

38:02

Um, so when you,

38:04

when you see a fallen fragment sign within a,

38:06

a loosened bone lesion, um,

38:08

the number one thing you're gonna be thinking

38:10

of is what's referred to as a unicameral bone cyst.

38:13

And the way that you could confirm this, if you had to,

38:15

if you do an MRI, you'd expect this

38:17

to look like a cyst anywhere else in the body

38:20

where you just have a thin peripheral rim of en

38:22

of enhancement, and the rest of it would be filled

38:24

with either fluid or maybe even blood

38:26

because of the fracture.

38:28

Um, but you wouldn't expect like our aneurysmal bone cyst

38:30

to have multiple fluid, fluid levels.

38:33

All right, um, moving on to, uh, case number 13.

38:36

Um, we have an elbow radiograph on a pediatric patient,

38:40

and the question is, what is the diagnosis?

38:43

Very great. So, um, the majority

38:45

of the audience did get the answer correct.

38:47

The answer is, um,

38:48

that this case is showing an osteochondral defect

38:50

involving the capal.

38:52

Um, so you could see it on this view really nicely as this,

38:55

uh, as this lucency involving the Capella.

38:58

Um, you might be able to make it out on the sagittal view,

39:00

but the, the, uh, the lateral view was really shown to just

39:03

demonstrate a large joint effusion.

39:06

Um, I will show the MRI on this patient also.

39:08

Um, but one, one mechanism of injury that I wanted

39:11

to play up is this idea of a valgus overload.

39:14

Um, so in the throwing athlete, like, uh, pa patients

39:17

that play baseball or even, uh, gymnasts, um,

39:21

your elbow is co connected basically by, um,

39:24

your ulnar collateral ligament on the ulnar side

39:27

and your, uh, radial collateral ligament on the

39:29

radial side of the elbow.

39:31

And in people that do throwing athletics, um,

39:33

they're constantly putting tension on, on the, um,

39:37

ulnar aspect of the elbow,

39:38

and they're constantly putting repetitive compression

39:41

on the lateral side of the elbow.

39:43

Um, so this repetitive tension on the ulnar side

39:45

of the elbow eventually leads

39:47

to ulnar collateral ligament terrace, you know,

39:49

maybe a partial tear of the UCL or even sprains of the UCL.

39:53

And this constant repetitive collision on the lateral side

39:56

of the elbow, um,

39:57

sometimes can produce these osteochondral defects

40:00

of the Capella, or you might wind up

40:02

with cartilage loss on the, on the,

40:04

or even fractures on the on or,

40:06

or osteoarthritis on the lateral side of the elbow.

40:09

Um, so this familiarity with this idea

40:11

of a valgus overload is important, um, for some of the,

40:14

the athletes, um, that you'll be seeing that play, uh,

40:17

you know, throwing athletics, um, here's some

40:21

of the MRI images and I'll actually just load up the,

40:23

the MRI, um, uh, so we could see it live.

40:27

Um, so you see as I'm panning around on the coronal view,

40:32

you could see the nice cartilage that's, uh, coating, um,

40:35

the, the ulna and the troia right here.

40:37

And then as I kind of march my way around,

40:39

you could see the cartilage on the radial head,

40:41

but then I'm encountering this, uh, defect

40:42

that's involving both the bone

40:44

and the articular cartilage, um, on the Capella

40:47

and, uh, deep to the side of the osteochondral defect.

40:50

There's some cystic changes involving the, the Capella.

40:53

Um, on the sagittal, um, projection, um, we could see

40:57

where this osteochondral defect has occurred on the Capella.

41:01

Um, it's, uh, it's along the articular aspect

41:04

of the capal right here.

41:06

And even nicely, you could see this loose body within the

41:08

posterior aspect of the joint, um, which is likely composed

41:11

of, uh, the, uh, cartilage, um, uh,

41:14

overlying a tiny sliver of a bony fragment.

41:17

Um, um, so that's, uh, that's an example of

41:20

what these look like on MRI.

41:21

Here's that, uh, interarticular fragment right here.

41:24

Um, you imagine that if this,

41:26

if this was still somewhat vitalized, the bone

41:28

and cartilage, you can imagine maybe the surgeons could kind

41:31

of plug it back into place

41:33

and then maybe put a screw across it or something,

41:35

and maybe the bone fragment will heal.

41:37

Um, so bones could potentially heal,

41:39

but cartilage really can't.

41:41

Um, so it might be the sense

41:42

that maybe they can't find a way to get this to heal.

41:44

So, you know, maybe you remove this fragment

41:46

so you don't wind up with locking sensation of the elbow.

41:49

And then maybe you drill a few holes into the bone here, um,

41:53

called microfracture surgery, um,

41:55

to try to stimulate healing.

41:57

Or another thing you could do is basically put a graft,

41:59

like take a cadaver, um, piece of bone and cartilage

42:02

and plug a bunch of a cadaver bone

42:04

and cartilage into this defect, um,

42:06

where maybe once the bone heals together, you'll wind up

42:08

with at least, at least some cartilaginous surface.

42:11

Um, 'cause without the cartilaginous surface,

42:13

you could imagine that, um, this patient, you know,

42:16

they might only be, um,

42:18

they might only be like 13 years old.

42:19

You can imagine by the time that they're 50 years old,

42:21

they're gonna have a really bad osteoarthritis of the elbow,

42:24

um, because of this injury.

42:27

Right. Um, moving on to case 14.

42:30

Um, so the question here will be

42:32

what is the most likely diagnosis?

42:34

All right, great. Um, a bit more split

42:37

on the audience, uh, here.

42:38

Um, still the majority chose a Ewing sarcoma,

42:41

which is the correct answer.

42:42

And the, um, um, the real, uh, um, um, I guess the one

42:46

to really confuse people is the idea of osteosarcoma.

42:49

'cause those are the, the two big

42:50

differentials at this location.

42:52

And also some people recognize this large soft tissue mass.

42:55

Um, so some people even chose the soft tissue sarcoma.

42:58

Um, the, the takeaway findings on this case is, uh,

43:01

we're dealing with a pediatric, uh, patient.

43:03

You could kind of make out their sacrum indicating

43:05

that it's a pediatric patient.

43:07

Um, we've got, um, involvement of the pelvis.

43:10

We can see that there's permeated involvement

43:12

of the iliac bone.

43:14

Um, however, you really can't make it out that much, um,

43:16

on this, on this bone filter.

43:18

But what we are seeing is, uh, what's referred to

43:20

as onion skin periosteal reaction.

43:23

So we see, basically the body is responding to this, uh,

43:26

infiltrative tumor involving the pelvis,

43:28

which is expanding out into the soft tissues, um,

43:31

by first trying to prevent it from

43:32

getting to the soft tissues.

43:34

So the body first laid down a layer of periosteal reaction,

43:37

then the tumor broke through that, um, the body tried

43:39

to lay down another layer of periosteal reaction,

43:42

then the tumor broke through that.

43:43

Then the body tried to lay down another layer

43:45

of periosteal reaction, and eventually the tumor won

43:48

and broke out, um, of the bone

43:50

and extended into the soft tissues.

43:52

Um, so one pearl is this onion skin periosteal reaction

43:55

indicating you're dealing with an aggressive, uh, tumor, um,

43:58

and most typically Ewing sarcoma.

44:01

But another pearl to this case is, um,

44:03

if you have a large soft tissue component of a mass, um,

44:06

asymmetrically proportion to the amount of bony involvement,

44:10

um, you wanna be thinking of small round blue cell tumors,

44:13

um, you know, tumors that might be able to kind of seep

44:15

through the crevices of the bone without completely just

44:17

destroying the cortex.

44:19

Um, and I think that's, uh,

44:20

what we have going on in this case

44:22

where the tumor might be slowly, um, seeping through some

44:24

of these, uh, verian canals in the bone.

44:27

Um, so when you wind up with this large soft tissue mass,

44:29

um, with relative lack of like cortical destruction, um,

44:33

think about small round blue cell tumors that'll take you in

44:35

the direction, in this case of either Ewing

44:38

sarcoma or lymphoma.

44:39

Um, and then obviously you realize once, uh,

44:43

a lymphoma typically occurring in people that are

44:44

between like 20 and 60 years old, um,

44:47

or even older, um,

44:49

whereas this was occurring in a pediatric patient.

44:51

So that would be the giveaway on this case.

44:53

Um, here's an example of

44:54

what their CT looked like in case you wanna

44:56

to see the images live.

44:58

Um, this is that large soft tissue mass look,

45:00

it's completely out of proportion, um,

45:02

to the ilio SOAs on, on this side of the pelvis.

45:04

And you could see it even kind

45:05

of tracks down along the ilio.

45:07

So as this mass, um,

45:09

and you could see when I switched

45:10

to these, uh, bone filters.

45:12

Um, the, the, while we do have all these, uh, nice sheets

45:15

of, uh, laminated

45:17

or onion skin perote reaction, the degree

45:19

of boney destruction compared to the soft tissue mass, um,

45:22

is somewhat out of proportion.

45:24

Um, we have less, less, uh,

45:26

cortical destruction as compared to this.

45:28

Like you'd imagine that if there was a large cortical,

45:30

a large mass like this, you'd expect this

45:31

to completely be destroyed if this was, uh, any other tumor.

45:35

Um, all right, so I'll, I'll kind of navigate out

45:38

of this case and we'll, um, so this will be the,

45:40

the last case with a question.

45:42

Um, so case number 15.

45:44

Um, and the, the question is, uh,

45:46

what is the most likely diagnosis?

45:49

Very great and, uh, interesting.

45:50

Um, we have kind of a split between the audience,

45:52

between osteomyelitis

45:54

and, uh, osteosarcoma as the two, uh, leading answers.

45:58

Um, so I'm assuming that most people realize

46:00

that we have a infiltrative lesion involving the proximal

46:03

humerus here, um, with a kind

46:05

of a dense sclerosis involving the lesion, um,

46:08

which you might think of as a osteo matrix.

46:11

And then we have this, uh, very aggressive appearing, uh,

46:13

periosteal reaction, um, on both sides of the humerus here.

46:17

Um, so we're thinking of something aggressive

46:19

and, you know, chronic osteomyelitis can have sclerosis, um,

46:23

and osteosarcoma can have this, uh, osteoid matrix

46:27

or cloud-like matrix.

46:28

Um, one of the giveaways in this case is, um, um, kind

46:32

of hidden in the corner right here is

46:34

that we have a ossified axillary lymph node.

46:36

Um, and then also on the ct we have ossified pulmonary

46:39

metastases and ossified pleural metastasis, um,

46:43

with a large pleural effusion.

46:45

Um, and this is all in a pediatric, uh, patient.

46:47

Um, so the, the diagnosis that I was, uh, trying

46:50

to get at was a metastatic osteosarcoma, um,

46:53

where we have this aggressive periosteal reaction, um,

46:56

and we have this osteoid matrix, uh, infiltrative lesion,

46:59

um, with metastatic disease to even in the lymph node

47:02

and also to the lungs.

47:03

Um, here's this, uh, patient's, uh, chest ct.

47:06

Um, so you could get a better perspective of

47:08

what this is looking like,

47:09

and I'll even put it in bone filters.

47:11

Um, you can see these, uh, ossified, um,

47:14

pulmonary metastases, even hilar metastases, um,

47:18

and ossified, um, even in the pleural space.

47:21

Um, one random question that you might encounter.

47:24

Um, um, osteosarcoma metastases can cause a

47:27

pneumothorax in the lung.

47:28

Um, this case doesn't demonstrate that,

47:30

but you know, they're kinda like you're forming these

47:32

nodules that are forming bone

47:33

and they might kind of, uh, puncture the lung.

47:36

Um, another thing

47:37

to realize is if you did a nuclear medicine bone scan on

47:40

this patient, all of these metastatic deposits will light up

47:43

because, uh, they have the osteoid matrix.

47:45

Um, here's that axial layer lymph node

47:47

with the osteoid deposits.

47:49

Um, and, and here's the appearance of the humerus with this,

47:51

uh, periosteal extent.

47:53

Um, um, here's an image of what their MRI looks like.

47:58

Um, and the MRI has this, uh, surrounding area.

48:00

This, this black line that kind of circumferentially goes,

48:03

um, about the humerus here is basically the periosteal, um,

48:07

uh, the periosteum trying to retain the tumor.

48:10

And all of this material that's in between the periosteum

48:13

and the bone is actually tumor

48:14

that's spread deep to the periosteum.

48:16

And you imagine in this case, it probably even broke

48:18

through the periosteum somewhere.

48:20

Um, and, you know, basically got a vascular invasion, um,

48:23

which led to the metastatic disease.

48:26

We hope you enjoyed that replay.

48:28

Dr. Scott Schiffman is with us for a live q

48:31

and a, so if you've got any questions, please go ahead

48:34

and submit those into the q

48:35

and a feature so we can get to as many questions as we can

48:38

before we say goodbye.

48:41

Dr. Schiffman, thank you so much for being here today.

48:44

Awesome. We've got one question right now

48:45

in the q and a feature.

48:47

I'm not sure if you can see it, but I did chat it

48:48

to you if you want to check that out.

48:52

Sure. Um, I think the question was what's the youngest age

48:54

that I've ever seen renal osteo dystrophy?

48:57

Mm-Hmm. Um, and I, I have seen it quite young.

49:00

Um, I don't, I don't know it off had,

49:02

but I, I imagine probably someone even in their thirties,

49:05

um, ba basically you just need a patient

49:07

to have, uh, renal failure.

49:09

Um, you know, sometimes they have, uh, you know,

49:11

say like lupus or,

49:12

or disease that might lead to like early renal failure.

49:15

Um, and that could set them up

49:17

for secondary hyperparathyroidism, so, you know,

49:20

you could wind up with patients on

49:21

dialysis that are pretty young.

49:23

Got it. Great. Thank you so much.

49:25

Go ahead and ask your questions using that q and a feature.

49:29

And, um, I got one.

49:31

Um, and what is the pathophysiology

49:34

of the regular jersey spine?

49:36

Oh, okay. Um, I think I got asked this the last time

49:38

that I gave this lecture.

49:40

Um, BBB basically, um, uh, patients that have, uh,

49:44

chronic renal disease, um, they go on

49:47

to get what's called secondary hyperparathyroidism.

49:50

Um, so they wind up with a increasing, uh, PTH levels.

49:53

Um, the, the PTH uh,

49:55

hormone will stimulate osteoclastic activity, um,

49:59

and then the osteoclast will, um, result in bony resorption

50:03

and re releasing calcium into the bloodstream.

50:05

So you wind up with elevated calcium

50:07

and decreased, uh, phosphorus in, in those patients.

50:11

Um, so th this is a process that's occurring that

50:15

for whatever reason at the interface of cartilage ligaments,

50:19

um, um, um, locations,

50:24

um, and that's what's producing these areas

50:26

of bone erosive changes as well as sclerosis.

50:29

Um, so where this occurs in the vertebral bodies is at the

50:32

vertebral body end plates.

50:33

Um, sometimes you could see it as like kind

50:35

of like s small SMLs notes,

50:37

and sometimes you could see it more inflammatory

50:39

where it's more like sclerotic, uh,

50:41

laying down on the upper and lower end plates.

50:44

There was another question

50:45

that got asked the last time you did this lecture that, um,

50:50

we could revisit, um, are rice bodies attached to

50:53

or originating from the synovial membrane,

50:55

and then do they shed into the arterial cavity?

50:58

Yeah, so, um, so the cases of rice bodies, uh, basically

51:03

the synovium becomes necrotic

51:05

and sloughs off, um, from,

51:07

from the synovial lining into the, either into the joint

51:10

or in the case that I showed into the bursal, uh, cavity.

51:13

Um, and then you wind up with multiple,

51:15

like sloughed off pieces of synovium

51:17

that are now intraarticular

51:19

and then, um, kind of similar to like rocks at the beach,

51:22

um, where they're repetitively kind of pounded by waves.

51:25

Um, you wind up with like kind

51:27

of all these like smooth surface, almost equal in size, uh,

51:30

bodies, um, that are kind

51:32

of well polished from them all kind

51:34

of rubbing against each other.

51:36

Um, so that, that's what gives the appearance

51:38

of rice bodies on, on imaging

51:39

and pathology is that you wind up with just numerous

51:42

of these, um, kind of necrotic synovial bodies

51:47

that have fallen off from the necrotic, uh, synovium.

51:50

Um, and as we discussed in the lecture, the,

51:53

the most typical causes is rheumatoid arthritis, um,

51:57

tuberculosis or synovial chondro mitosis.

52:01

Got it. Thank you. We've got another question in

52:03

the q and a feature.

52:04

If you wanna pop that open?

52:06

Why doesn't such a pattern come in

52:08

primary hyperparathyroidism?

52:12

Oh, um, that, that's an interesting question.

52:16

Um, I, I don't know the answer off had, I would have

52:20

to look it up, but I, I think it's possible

52:21

that you might get the same pattern.

52:25

Alright, well it seems like we don't have a lot

52:27

of questions, which means your case review was very

52:29

comprehensive and in depth.

52:31

Thank you so much for doing that. Again, Dr.

52:32

Schiffman, and thank you so much for joining us live today.

52:35

We really appreciate it.

52:38

All right, uh, thank you. I hope everyone enjoyed it.

52:41

Absolutely. Thank you so much. And thanks

52:42

for everyone else for participating in our NOOM conference.

52:45

You can access the recording of today's conference

52:48

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52:49

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52:52

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52:54

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52:57

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52:59

Mary Salvato for a lecture entitled The Role

53:02

of the Radiologist in Multidisciplinary Management

53:05

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53:07

You can register for this free lecture@mrionline.com

53:10

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53:11

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53:13

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