0:02

Hello and welcome to noo Conference, hosted by modality.

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Noom Conference connects the global radiology community

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radiologists from around the world.

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and previous noon conferences by creating a free account.

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Today we're honored to welcome Dr.

0:21

Steven Pomerance and Dr. Taylor Pomerance

0:24

for a lecture entitled, practical Aspects

0:26

of Post-Op Spinal Imaging and Reporting Part two.

0:29

Dr. Steven Pomerance is the CEO

0:31

and Medical Director of ProScan Imaging

0:33

and the founder of MRI Online.

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He's authored numerous medical textbooks

0:37

and MRI, including the MRI, total Body Atlas.

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Dr. Pomerantz is an AVID conference, lecturer, chairs,

0:42

fellowship training programs in a MAR and Advanced Imaging.

0:45

And Dr. Taylor Pomerantz completed her radiology residency

0:48

at the University of Pennsylvania, where she also served

0:51

as chief resident from 2021 to 2022.

0:54

She completed a fellowship in neuroradiology at the

0:56

University of Utah.

0:58

She's on staff at ProScan Imaging full-time specializing in

1:01

neuroradiology and also serves

1:03

as an adjunct professor at the University of Utah

1:05

and the division of neuroradiology.

1:07

That's a lot, guys. That's the end of the lecture.

1:09

Please join Dr. Pomerantz in a q

1:11

and a session where you'll address questions you

1:13

may have on today's topic.

1:14

Please remember to use the q

1:16

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

1:19

as many as we can before our time is up,

1:21

but that we are ready to begin today's lecture.

1:23

Dr. Pomerance, please take it from here.

1:27

Well, good afternoon, good morning,

1:30

good evening, wherever you are.

1:31

Thanks for joining us.

1:33

We're gonna be talking about the postoperative spine mostly,

1:38

and, uh, contradistinction to our initial lecture,

1:41

which was an introductory lecture about terminology

1:44

and how to describe disc abnormalities.

1:47

I'm gonna share this platform with, with Taylor Poi,

1:50

who's gonna do perhaps the more interesting part

1:52

of the talk, uh, case-based abnormalities associated

1:56

with a postoperative spine.

1:57

I'm gonna focus on the surgical procedures

2:01

and the devices right now, which we have long ignored

2:04

as radiologists, not the neuroradiologist,

2:07

but certainly the, the general radiologists reading spine

2:10

and sometimes even the ortho MSK radiologists reading spine.

2:14

We're gonna be talking about the surgical approach

2:17

and hardware selection, basic imaging guidelines for MRI

2:21

of the postoperative spine with hardware.

2:24

And the, these will fall mostly to, uh,

2:26

Dr. Taylor Pomerance.

2:27

And then reviewing postoperative complications in the

2:30

subacute, uh, acute

2:32

and chronic periods that will fall also to Taylor Pom.

2:36

The hallmarks of operative spine, uh,

2:40

intervention are decompression of a compressed area.

2:44

Could be a nerve root, it could be the sac,

2:46

could be the cord stabilization fusion,

2:49

and when appropriate lesion excision.

2:52

Uh, some of our colleagues have even gone so far as

2:55

to excise spurs in the cervical region.

2:58

And surgeons are very sensitive to the difference

3:02

between soft discs, in other words, extrusions and,

3:06

and, uh, other types

3:07

of herniations versus disc osteophytic complexes.

3:11

'cause the risk of excising a disc osteophyte,

3:14

especially in the cervical spine,

3:15

is much higher than removing a disc.

3:18

We'll talk about, um, timing

3:20

and modalities a little bit later on.

3:23

Um, and,

3:24

but right now I wanna talk about imaging intervals

3:27

for non instrument instrumented decompression

3:29

with symptom resolution.

3:31

Uh, there doesn't need to be any imaging

3:33

for instrumented fusion.

3:35

An arthroplasty, usually an x-ray is performed at six weeks,

3:38

three, six, and 12 months for a long segment.

3:42

Fusion for deformity correction, uh,

3:44

usually these patients will be followed two

3:46

years and and beyond.

3:48

And for new persistent persistent pain, um,

3:51

whether it's radicular

3:53

or axial, uh, in the center of the back, which

3:56

by the way has a pretty low yield, uh,

3:58

or the patient has a neurologic deficit, you're going

4:01

to image immediately.

4:02

Just, just a point that I did not drive home in the last,

4:06

uh, discourse that we had together.

4:08

When patients have axial pain, in other words,

4:10

when they complain of back pain

4:12

or a back ache, the odds of you finding the cause

4:17

drop by at least 50%,

4:19

or as somebody that has radiculopathy,

4:21

you're almost always going to find the cause

4:23

of the radiculopathy.

4:24

So in your history,

4:26

it's very important you pay attention, uh, to this fact.

4:29

Some terminologies, most of you are familiar

4:32

with A-C-D-N-F anterior cervical discectomy infusion,

4:36

previously known by the name Smith Robinson Procedure.

4:40

Clouded procedure where you put a bone DOL graft in the disc

4:44

space, it hasn't really changed, uh, very much.

4:47

There, there are plates

4:48

and screws that go in anteriorly through a,

4:51

a parathyroid anterior incision in the neck.

4:54

And then the disc space is fused with, with either a cage

4:58

or with BMP bone morphogenic protein, or both.

5:02

Then we have the ply, the posterior lumbar interbody fusion,

5:05

the T lift, the transforaminal lumbar interbody fusion,

5:08

the X lift, the extreme lateral interbody fusion,

5:13

the A lift, the anterior lumbar interbody fusion,

5:16

and the O lift, the oblique lumbar interbody fusion.

5:20

That that is a lot.

5:21

And then the disc materials that we'll use, um,

5:24

w will often put in a cage.

5:27

The cage can be made of metal.

5:29

The plate cage can be made of plastic,

5:31

but frequently surgeons will put in ground up bone taken

5:35

from the ileum or from some other bone.

5:37

And this is known as bone morphogenic protein

5:40

and it's mixed in with some other interesting elixirs.

5:44

And then you've got artificial discs,

5:45

which are used in the cervical region.

5:48

And these are kind of bouncy H shaped structures.

5:50

And I'm gonna show you some picture

5:52

of these in a few moments.

5:54

So here's a summary. You'll see the slide, uh, two

5:57

or three times of the surgical AP approaches.

6:00

The P lift goes through either a laminotomy,

6:04

a keyhole laminotomy, or it goes through a laminectomy.

6:08

Or sometimes they'll even take the facet down, up to here,

6:11

a, a facetectomy and laminectomy

6:14

or laminotomy and facetectomy.

6:17

Then you've got the T lift procedure, which comes obliquely,

6:19

where you have to take down the facet, uh,

6:22

still coming from, from the back.

6:24

And then you've got the XL, which goes right,

6:27

right in front of the foramen.

6:29

Um, it goes through the sous muscle.

6:31

So you know the lumbosacral plexus lives near here,

6:34

and that's a potential complication.

6:36

Then you've got the O lift

6:37

that comes in from the anterolateral flank, uh,

6:41

going transabdominally.

6:43

And then the A lift, which goes transabdominally.

6:47

I promised you a view of some of these devices.

6:49

Here are, uh, some of the cervical, uh,

6:53

prosthetic discs, and these are getting better

6:56

and better by the month.

6:58

Uh, I have a friend that had one

6:59

of these about three years ago, completely asymptomatic

7:02

with nearly full range of motion in his neck.

7:04

So it's like the little girl with the little curl.

7:06

When it's good, it's really, really good.

7:08

And when it's bad, it's hard.

7:10

Uh, but what these all share in common is they have this

7:12

little hinge mechanism so that, you know,

7:15

you can reproduce the normal cervical lordosis

7:17

and the patient will have kind of that bouncy feeling,

7:20

uh, in their neck.

7:22

Then you've got interbody cage devices.

7:24

I only wanna show a few of these two.

7:25

Here's a cervical interbody cage.

7:28

A right here can see it's a ring.

7:31

The BMP usually will go in the center.

7:33

The bone morphogenic protein,

7:34

which is nothing more than ground up

7:36

bone with a few elixirs.

7:37

Then you've got c the lumbar, uh, interbody cage.

7:41

And, um, these are usually paired.

7:45

And when you see paired cages, odds are you've had a cliff,

7:49

a posterior, uh, lumbar intervention.

7:52

And then you've got this letter D right here, which stands

7:56

for the T lift cage.

7:57

And usually the T lift cage and the anterior cages.

8:00

So cages that are not put in from the back are usually one

8:04

large horizontally oriented banana shaped ca cage.

8:09

So this is pretty simple and straightforward.

8:11

So if you look at the cage,

8:13

that's gonna give you a good idea of

8:15

where you should be looking for the complications.

8:18

'cause the complications are going to be

8:20

where they enter the spine.

8:22

Here is some plating systems.

8:24

I don't want you to go to sleep on me,

8:25

so I'm only gonna show you three.

8:27

I'm gonna show you the typical anterior plating system

8:30

for the cervical spine.

8:32

Uh, this is one for the lumbar spine.

8:35

And I'll comment in a few minutes where these,

8:38

where these screws and, and rods should go

8:42

because they are different in the cervical spine than they

8:44

are in the lumbar spine.

8:46

And then for posterior lumbar fusion, just

8:48

for cultural purposes, the steffy plate is, is very famous.

8:53

And, uh, it is a device

8:54

to help stabilize the posterior column of the spine.

8:58

The cliff, the posterior lumbar interbody fusion

9:03

incision in the lower back, uh, usually close

9:05

to the midline, but slightly off midline.

9:08

The lamina is removed. So it's a, it's a laminectomy.

9:11

The facet is usually preserved.

9:13

Disc material is removed,

9:15

then they put in the bone graft in the interbody cage,

9:17

which is common to most of these procedures.

9:19

And then screws and rods are placed

9:22

to stabilize during fusion.

9:23

So here's what it looks like.

9:24

They've gone in from the back slightly off midline.

9:27

They've done a discectomy.

9:29

And many of you notice that when they do the discectomy,

9:31

it looks like the volume

9:32

of the disc is almost the same as it was before.

9:35

So I'm not really sure how much of it they, they get out,

9:38

uh, on a consistent basis,

9:40

but they take out as much as they can,

9:42

including the extruded disc material.

9:44

And then they, they put the cage in.

9:46

And a good cage position would be central

9:49

or slightly anterior, uh, of central.

9:52

Don't like it to be butted up right against the

9:54

posterior longitudinal ligament.

9:56

In looking from the back, you've,

9:58

you've made an open window here to look through.

10:01

So your cliff entry point is right here.

10:04

So a retractor will reach onto the durup,

10:07

it'll pull the fecal sac over

10:09

and you can see a content, a content,

10:11

and injure the nerve roots.

10:13

And this is a known complication of the cliff.

10:16

Here are some cliff cages.

10:17

Remember, dual cages, two cages pointed from A

10:21

to P from anterior to posterior, usually a cliff.

10:24

And here they are. Here are the two cages.

10:26

Looking at it in the coronal projection,

10:28

here it is in the axial projection.

10:30

You can see a lot

10:31

of the times they're not exactly parallel to one another.

10:34

They're usually perpendicular to the arc, uh,

10:37

of the disc space to the arc of this pancake.

10:40

Two cages cliff pedicle screws.

10:45

We see pedicle screws together every day.

10:48

Um, in the lumbar region.

10:49

I like my pedicle screws to be in the upper third

10:52

of the vertebral body, but not touching

10:55

or entering the osteochondral nplate or disc.

10:59

I like the screws to be as far in as possible,

11:01

but not perforating the cortex.

11:05

This is in contradistinction to the cervical region

11:09

where you absolutely need as much purchase as you can get.

11:13

If you're putting screws in from the back

11:16

and perforation of the cortex is permissible.

11:19

It, it improves the purchase and the stability,

11:21

but only a tiny weenie amount, uh,

11:24

of such perforation is permissible.

11:27

So a little bit different.

11:28

Also, I like my lumbar screws to be parallel

11:33

to the disc space at each level.

11:34

So the, they'll be slightly angled.

11:38

The T lift procedure

11:40

and the T lift incision in the back

11:42

removes the facet rather than the lamina

11:45

and the intervertebral disc from one side of the spine.

11:48

So this is good for eccentric disc disease.

11:52

You insert a bone graft or cage just like you did before,

11:56

and you add screws and rods.

11:59

So here you are. This time you're not going to go

12:03

and pull the sack over.

12:05

You're gonna go in obliquely from a more lateral approach.

12:08

It's still postero lateral.

12:11

And uh, there are some advantages

12:13

of the T lift over the P lift that we will discuss.

12:17

Um, here's an example of where you would go in on a T lift,

12:22

and you're gonna be right in the region

12:25

of the foramen once you take down this facet.

12:28

So some people will call it a

12:30

foraminal posterolateral foraminal approach.

12:33

Uh, surgical procedure.

12:36

The advantages of A TL F1, it minimizes disruption

12:40

of the spinal nerves 'cause you don't have

12:42

to pull on the fecal sac.

12:44

It promotes solid fusion like many of them do

12:47

by placing the graft, preferably in the load bearing zone.

12:52

And it can be done with minimally invasive techniques.

12:55

So there's less blood loss,

12:56

there's less recovery time than there is for a cliff.

13:01

And my experience, the amount of muscle loss is greater

13:04

for ALY than for a T lift.

13:06

So here's a comparison. These are the two most

13:09

common that are used.

13:10

So if you learn these two

13:12

and nothing else, you're doing great, uh,

13:15

direct from the back in the midline off to one side,

13:18

posterolateral facetectomy, laminectomy

13:22

or laminotomy nerve manipulation.

13:25

More versus T lift, less insertion of cages,

13:29

usually two small cages oriented from A to P,

13:33

usually one large cage either oriented obliquely

13:37

or horizontally.

13:39

Recovery is often a little quicker with a T lift

13:42

because it is a less invasive procedure.

13:45

So here's again, a summary of PLF and the oblique tlif.

13:49

Then we get into direct lateral xlif, the anterolateral oli

13:54

and the anterior A L.

13:58

So let's talk about the oli.

14:00

It's a pretty good size incision, almost five centimeters,

14:03

uh, just about two inches on the side of the abdomen.

14:06

You have to navigate through an antis sous corridor

14:10

between the sous muscle

14:11

and the peritoneum to reach the target intervertebral disc.

14:16

So you could injure the sous muscle,

14:18

you could injure the lumbosacral plexus.

14:21

Everything else is pretty much the same.

14:23

Disc removal and cage insertion with or without BMP.

14:27

Usually BMP is in included.

14:30

And unlike X lift O lift preserves the s sos muscle.

14:35

So injury to the s sous muscle is more common

14:38

with an X lift than an O lift.

14:40

And atrophy of the s sos muscle is more common with an xlif.

14:44

And a an with an xlif over an oli,

14:48

an oli reduces the risk to injury to the lumbosacral plexus

14:53

or the lumbar plexus, but doesn't completely avoid it.

14:56

It also minimizes risk

14:58

to the vascular structures when compared with the XL.

15:03

This is often accompanied by anterolateral

15:05

or posterior screw fixation.

15:07

Like most of our other, uh, lift procedures.

15:10

One potential complication

15:12

of an oli is something called cage subsistence.

15:15

This can occur with any cage placement,

15:18

but it's a little more common with the oli.

15:20

Uh, this is settling of the cage into the, uh,

15:24

disc end plate complex.

15:26

Uh, the amount of settling varies from 10 to 50 per 50%,

15:30

and this occurs at almost one in five cases.

15:33

So this is a pretty common complication, uh, of the oli f

15:37

the ex LF This is an extreme lateral interbody fusion.

15:41

I'm not gonna spend a lot of time on it.

15:43

Uh, it's becoming a little bit less common.

15:46

Uh, it's alleged minimally invasive.

15:49

You do have to make an incision on the side of the body.

15:52

Uh, the incision is smaller than with an oli.

15:55

And all of the other same things are done, including, uh,

16:00

placement of a cage with BMP alift,

16:04

an alift or anterior lumbar interbody fusion is a type

16:08

of fusion surgery that involves

16:10

accessing the spine from the front of the body.

16:12

In other words, you go through the abdomen,

16:15

you're having a midline abdominal incision,

16:18

and you're performing the fusion from an abdominal approach.

16:22

This is usually used to treat degenerative disc disease,

16:26

especially at L five S one where there is a fair amount of

16:31

sacral nplate degeneration.

16:33

So here is a diagram, uh, of a couple of a lifts.

16:36

Here's an alift that looks a lot like a a cervical spine

16:40

except it's a lumbar spine.

16:42

Uh, anterior placement of a plate

16:44

with screws coming from the front as opposed to

16:48

screws that we discussed.

16:49

Stabilization screws coming from the

16:51

posterior column in the back.

16:52

Here they are in the back.

16:54

And then here is where the alift has still remained.

16:58

Semi-popular L five S one advanced

17:01

degenerative disc disease.

17:02

You come in from the front

17:03

and then you reach down under the sacrum

17:05

and you drive this oval shape, uh, screw or

17:10

or cage that is riveted.

17:12

And you, you bridge the L five S one level.

17:15

This takes a little bit of training to do properly

17:18

and also you're going through the abdomen,

17:20

so you gotta be a real surgeon.

17:23

Um, so we've got a lift, OLXL, TL, and PLF.

17:27

So let's summarize the types of lifts. Surgical approach.

17:32

P lift from the back close to the midline.

17:35

TL just off the midline for eccentric disc disease.

17:39

A lift for L five, S one, XLF from the side

17:44

O lift not listed here.

17:45

Also from the side disc access both sides.

17:49

One side, yes, direct access to everything,

17:53

but mostly central XLF lateral er,

17:57

mostly one side muscle disruption

18:01

really high in a P lift.

18:02

So you look at somebody, they have no back muscles left.

18:06

This is a potential problem, but people don't talk about.

18:09

But I always grade the severity of sarcopenia.

18:13

I eyeball it less than 25, 25 to 50,

18:18

50 to 75 or greater than 75.

18:21

And I do that with my eyeball.

18:22

It doesn't have to be exact muscle disruption,

18:25

less with a T lift.

18:27

Almost non-existent with an A lift

18:29

and X lift, minimal in the back.

18:31

But you do run the risk of a s OAS

18:34

or LS plexus injury in inexperienced hands,

18:38

nerve retraction risk is high,

18:40

but I've already talked about this over here for an X lift.

18:43

The lumbo sacral plexus fusion material two cages front

18:47

to back with BMP

18:49

or a bone graft for the PL F1 cage.

18:52

One cage, one cage all large and all associated with grafts.

18:58

PL commonly used for central

19:00

or bilateral disease TLF unilateral disease.

19:04

What do we use LIF for?

19:05

Mostly advanced degeneration of L five

19:09

S one XLF.

19:11

You can go L one to L four,

19:13

but not, you should never use an XLF at L five S one.

19:17

Recovery time about the same.

19:19

Although people that do these other procedures will tell you

19:22

that there's a lower recovery time.

19:24

I'm not sure that's really true

19:26

and stability is strong with all of them.

19:29

Cosmetic considerations.

19:30

Midline scar for a PLF small scar on the back for A TLF.

19:34

Uh, a lower abdominal scar near the midline for an a lift

19:38

and a side scar almost two inches for the X lift.

19:42

With that, I'm going to turn the clinical case review part

19:47

of this talk over to Dr. Taylor Poer.

19:51

All right, thanks for joining us everyone.

19:53

Uh, so now we're gonna cover, uh, mostly Mr uh,

19:55

postoperative complications in patients

19:58

who have undergone spinal surgery.

20:00

So this is, uh, fairly comprehensive,

20:03

but by no means exhaustive list of some

20:05

of the pathologies we see in post-op spine patients, uh,

20:09

organized by time course,

20:10

and there are of course, several entities

20:12

that can span multiple time courses from the

20:14

acute to chronic phase.

20:16

We're gonna try and touch on a majority of these, uh,

20:19

during the next 20 or 30 minutes here.

20:22

Before we get into that, we'll just briefly touch on high

20:25

level, um, tenants of I imaging, uh,

20:30

patients with hardware and Mr uh, the text

20:32

and white, I mean these should be standard protocol.

20:34

Um, anywhere, uh, that patients

20:37

who have undergone spinal surgery with instrumentation,

20:39

uh, are being imaged.

20:41

Uh, the text in yellow are, uh, additional considerations,

20:44

things that can be further tweaked to help reduce, uh,

20:47

susceptibility artifact.

20:49

Uh, just as example, uh,

20:51

this is the same patient scanned on three Tesla magnet,

20:53

you can see is tons of susceptibility artifacts.

20:56

Non-diagnostic exam.

20:57

Essentially that patient returned, it went on a 1.16

21:00

or a lower field magnet, um, and a very diagnostic quality.

21:06

This is also a nice example.

21:07

This was, uh, an article

21:09

that was published earlier this spring in radiology of, uh,

21:12

postoperative, uh, cervical spine.

21:15

Um, that nicely demonstrates the pile up artifact

21:18

that we are all so used to seeing in, uh,

21:20

cervical spine patients.

21:22

Um, and simply here on the right broadening the receiver

21:26

bandwidth, uh, gets rid of that artifact.

21:30

So we're gonna jump right into some cases.

21:32

We'll start with the obvious ones.

21:34

Uh, this is a gentleman who underwent a two level, um,

21:38

spinous process clamp

21:40

and develops severe low back pain

21:42

with bilateral lower extremity radiculopathy.

21:45

Uh, he went to mr and we've got sagittal T one, T two

21:48

and stir sequences.

21:50

We can see there's a dorsal epidural fluid collection just

21:52

above the upper site.

21:54

It's ISO on T one and right on T two and stir sequences.

21:58

Uh, there's mass effect on the, uh, adjacent coto

22:00

and nerve roots with ventral ventral

22:02

displacement and compression.

22:05

And this is of course, uh, our expanding hematoma.

22:10

The two important points I want to make here are first, uh,

22:14

hyperacute blood product can look just like water on mr.

22:18

Okay. Um,

22:19

and the second point is, uh,

22:21

as hyperacute blood product transitions into the acute

22:25

phase, um, it will be gray on all sequences

22:28

and it can mimic a soft tissue mass.

22:30

Less important in a postoperative patient

22:32

because we have almost always have preoperative imaging on

22:34

these patients and we know that it wasn't there before.

22:37

Uh, more important in consideration of patients

22:40

who are presenting with spontaneous

22:42

epidural hematoma in the spine.

22:43

Okay, let's move on to a gentleman

22:48

who developed a right foot drop in the PACU following a

22:50

microdiscectomy on the right,

22:52

we have his preoperative MRIT two axial sagittal sequences

22:56

and see he's got a large right central

22:58

and cranial migrated extrusion.

23:00

The disc is very desiccated. It's dark on T two.

23:03

His post-op MRI looks almost identical, uh,

23:06

with the notable exception of the, uh,

23:09

intensity of the disc material.

23:11

It's very bright. Um,

23:13

so this gentleman headed acute recurrent extrusion.

23:16

It's taken back to the OR

23:17

and they found a large amount

23:19

of freshly extruded disc material.

23:21

Uh, the other consideration here would be some

23:23

hemorrhagic granulation tissue.

23:25

Uh, disc of course we know does not enhance it.

23:27

Desiccate over time, uh,

23:29

acutely extruded disc material can be quite bright on T two

23:32

and stir sequences and may even appear cys like

23:35

or mimic CSF.

23:37

Um, and these are not always symptomatic

23:39

in this case, of course it was.

23:41

And this patient has a very nice example of, uh,

23:45

both recurrent extrusion and perdu fibrosis

23:48

or as what some of you may refer to as granulation tissue.

23:52

Uh, we can see we've got consecutive axial slices

23:56

through the L five S one level

23:58

and on the unenhanced T one sequences recurrent disc

24:02

and enhancing grant, recurrent disc

24:04

and peroneal fibrosis are essentially indistinguishable

24:07

on T one sequences.

24:09

Uh, with contrast, we can see at the upper level there is,

24:13

uh, some gular non enhancing tissue here, uh, consistent

24:17

with recurrent extruded disc.

24:18

And then of course surrounded by all

24:20

of this enhancing peroneal fibrosis,

24:23

which also extends coddly along the right lateral recess.

24:27

This is also a normal postoperative finding.

24:29

Uh, a little bit of nplate enhancement is normal.

24:32

It really should not be more than, uh, one

24:34

to two millimeters thick.

24:36

Um, if you're looking at nplate enhancement

24:38

that's greater than that, you have

24:39

to start thinking about more nefarious things.

24:41

Um, nplate violation, infection, things like that.

24:48

So this is a case we sometimes see in patients

24:50

who have undergone spinal surgery.

24:52

Uh, we also see this in patients

24:54

who have had superal craniotomies for cranies.

24:57

Um, this patient came to ct, uh, following, uh,

25:02

surgery with delayed awakening from anesthesia,

25:05

which is a common presentation.

25:07

Uh, we've got

25:09

layering blood product along the superior cerebellar folia,

25:14

and this is an entity known as remote cerebellar hemorrhage.

25:16

We call it the zebra sign and radiology

25:18

because that's what it looks like.

25:20

Uh, it can be unilateral or bilateral.

25:23

And, uh, what it looks like on MRI really does not matter

25:26

because this is a CT diagnosis.

25:27

There's no need for these patients to go to mr.

25:33

The pathophysiology is, uh, thought to be a form

25:36

of hemorrhagic venous infarction, um,

25:39

from post-surgical CSF hypovolemia

25:42

and cerebellar sagging occluding.

25:44

The penetrating veins, uh, it can be asymptomatic.

25:47

Usually if you're seeing it on imaging, it's

25:49

because the patient's had trouble waking up from anesthesia

25:52

in the pacu, as was the case here.

25:54

Um, and it's typically self-limited,

25:55

but in rare occasions it can progress

25:58

to obstructive hydrocephalus.

26:00

Uh, warranting surgical intervention.

26:04

The remote name in the title denotes the distant location

26:08

from the operative site, not chronicity.

26:14

So this is a sort of a dreaded complication

26:16

of cervical decompression here.

26:18

Uh, this patient underwent a multi-level A CDF,

26:23

uh, for compressive myelopathy

26:26

and developed a dense right hemiplegia in the pacu.

26:30

She was sent emergently to MR.

26:33

And on imaging, uh, we can see she's got an expansile T two

26:38

and stir hyperintense,

26:40

almost short segment ho cord lesion at one

26:43

of the levels of decompression.

26:47

And this is an example of a white cord syndrome

26:50

or ischemia reperfusion injury.

26:52

It's a rare but dreaded complication

26:54

of cervical decompression on 2013 Chin published, uh,

26:58

some criteria to try and categorize as patients.

27:01

Uh, they're typically patients

27:03

who have severe spinal cord compression,

27:05

who have undergone decompression.

27:07

And these are kind of the keys here.

27:09

They develop neurologic deterioration usually within the

27:12

first three hours postoperatively.

27:14

Sometimes they wake up in the PACU like this, uh,

27:16

which was the case for this patient.

27:18

And they have profound neurologic de

27:22

profound neurologic dysfunction.

27:24

Uh, typically either, uh, dense hemi or quadriplegia.

27:29

Um, with proper management, uh, these patients have,

27:32

can have complete or partial

27:33

restoration of their neuro function.

27:35

You know, they usually go on the, um,

27:37

acute spinal cord injury, uh, pathway, uh,

27:40

treated with high dose steroids.

27:42

And that was the case for this patient.

27:44

Um, at nine months post-op, she had regained all

27:47

of her neurologic function, with the exception

27:49

of a persistent right foot drop.

27:51

Um, so why isn't this a cord infarct?

27:53

Because that would be the other, uh, differential here.

27:56

Cord infarct, watershed injury, well, timing

28:00

and, um, context related to imaging in

28:03

that timeframe is really the key here.

28:06

Uh, so patients with cord

28:07

and FARC have acute onset of symptoms,

28:09

but you know, we know that more than 50% of patients

28:11

with anterior spinal artery syndrome

28:14

reach maximal symptomatology at 12 hours, uh,

28:17

with the remainder of patients eventually progressing

28:20

to maximal maximal symptomatology by 72 hours.

28:24

Okay? Versus ischemia reperfusion injury patients, these

28:28

patients have profound deterioration within

28:30

the first three hours post-op.

28:31

It almost always happens in PACU and on imaging.

28:34

Uh, you know, when patients with reperfusion injuries go

28:38

to mr, they have a, uh, dramatic imaging finding correlating

28:41

to their neurologic deficit, uh, versus patients with, uh,

28:45

acute infarct and anterior spinal artery syndrome.

28:48

Uh, we know that, um, in up to 50% of patients

28:52

with cord infarct,

28:53

MRI can be negative in the first 24 hours.

28:56

Okay? Um, also with cord infarct, you know,

28:58

we're typically looking for, um, localization

29:01

to the gray matter, AL'S eyes, anterior horn,

29:04

um, so slightly different.

29:05

Mr. Appearance can eventually progress to look like this,

29:08

but it typically happens later in a later stage.

29:14

Pathophysiology here is thought to be from disruption

29:16

of the blood spinal cord barrier from rapid cord expansion

29:19

and acute increase in blood supply,

29:22

increasing the permeability to inflammatory s

29:25

and oxygen free radicals and wreaking havoc on the cord.

29:31

So this is, uh, an entity that is sort

29:33

of on a similar spectrum, uh,

29:35

that we don't technically see

29:37

necessarily in the acute setting.

29:39

Uh, this is a young gentleman who, uh, had a prior A CDF

29:43

and was re imaged for left radicular symptoms.

29:45

And this is an entity I see probably, hmm, once

29:49

or twice a quarter maybe.

29:51

I just had another case yesterday

29:53

and a case this morning of this.

29:55

Um, so this case came to us as a second opinion.

29:58

Uh, and the question was,

29:59

does the patient have multiple sclerosis?

30:02

So on the T two sequences on the left,

30:04

we can see there's a spindle shaped area

30:07

of stir signal abnormality with a central short segment, uh,

30:11

focus of enhancements, sort of flat appearing.

30:16

We've got this pre-op MR here

30:18

and we can see clearly had a compressive myelopathy at

30:21

that level at five six.

30:24

Here's another companion case.

30:25

Same finding, uh, this patient has,

30:28

uh, weakness and tingling.

30:30

Uh, the, this was also a second opinion, uh, case

30:34

and the history we got was a spinal cord tumor.

30:37

Um, we can see there's, uh,

30:39

stir signal abnormality in the cord with, uh,

30:42

this really nicely illustrates.

30:44

This is axial post contrast sequence through

30:46

that level circumferential white matter enhancement flat

30:50

pancake like sparing the gray matter.

30:52

And these are of course examples

30:54

of pancake like gadolinium enhancement.

30:56

Um, some hallmark features being circum white matter

31:01

enhancement, very flat transverse appearance, um,

31:04

at the center of a spindle shaped area of T two signal.

31:08

Uh, they localize immediately below the point

31:10

of maximal stenosis, which in the majority

31:12

of patients is at the C five C six level.

31:15

And you can see these on contrast preoperatively

31:18

or postoperatively.

31:19

We don't see it preoperatively

31:20

'cause most pre-op MRS are ordered without contrast.

31:25

It's a enhancement pattern of spondylotic myelopathy

31:27

and is also thought to kind of be on the spectrum

31:29

of blood brainin barrier disruption.

31:32

Um, the important, uh, things to note, you know,

31:35

it can persist well beyond a year on imaging.

31:38

Uh, but there really should be no progression

31:40

clinically or on imaging.

31:42

And if that's not the case, you need

31:44

to go back to a differential.

31:45

And the main things to consider would of course be

31:47

what were initially suggested here, demyelination

31:50

and neoplasm.

31:55

Let's move on to, uh, a young woman who had a, uh,

31:59

multilevel decompression

32:01

and she presented with two weeks of low back pain

32:03

and right lower extremity numbness.

32:05

We've got sagittal and axial T two

32:08

sequences through the operative level.

32:10

Could say she's got a large fluid collection

32:12

and laminectomy bed.

32:14

And our yellow arrow here on the axial sequence is denoting,

32:19

uh, A CSF jet.

32:24

Here's a companion case, another large, uh,

32:27

postoperative fluid collection and laminectomy bed.

32:30

This patient has multiple CSF jets

32:33

and, uh, we can see a large actual dural defect here.

32:38

Romy, these are of course examples

32:41

of postoperative pseudo meningo seals.

32:44

Um, you know, we see fluid collections

32:46

and laminectomy beds every day

32:48

and postoperative find patients.

32:50

Um, they're not all pseudo meningo seals.

32:52

The majority of them are not. Uh, we need

32:54

to see other supportive postoperative findings as well as,

32:58

um, you know, some, uh,

33:00

key features in patient's clinical presentations.

33:02

But on imaging, we're looking for CSF jet,

33:04

and that is, you know, we see

33:06

that from fast flowing CSF and spin defacing.

33:08

That's what causes the J phenomenon we see on Mr.

33:11

Uh, a frank dur defect as we saw in our second case.

33:14

Um, sometimes we can be tipped off

33:17

of pseudomeningocele if there's an enlarging postoperative

33:21

fluid collection over time.

33:22

Um, seromas should not enlarge, um,

33:26

or frank herniation of the clain

33:28

and nerve roots, which this patient actually had.

33:29

It's better demonstrated on a scrollable sequence if you're

33:32

not sure, but there's still very high clinical suspicion can

33:35

bring the patient back for a really thin, uh, T two weighted

33:40

sequences through level either kiss or fiesta sequence,

33:43

or you can proceed to a CQ mammogram.

33:48

Unfortunately, same patient in our second example, uh,

33:51

came back four months later.

33:52

They underwent successful closure of their, uh,

33:55

dural defect, uh,

33:56

but had new left lower extremity radiculopathy.

33:59

And now we see the patient has an empty fecal sac sign, uh,

34:03

plastering of the Cato equine

34:05

and nerve roots along the fecal sac here,

34:07

and also cord like clumping of some

34:08

of the Cato equine and nerve roots.

34:10

And this is of course, adhesive arachnoiditis.

34:14

Uh, hallmark is the empty fecal sax sign we look for.

34:17

Can also present as a pseudo mass, uh, from clumping.

34:21

And you can see it with or without enhancement.

34:23

Um, it's not always symptomatic,

34:25

sometimes it's an incidental finding.

34:27

Um, and in rare occasions we see nerve root calcification

34:30

or a ca calcific mass, which we refer to

34:34

as Titis Pacific hands.

34:36

And this is a very nice example of that

34:38

that I had a few weeks ago.

34:40

I promise you this is not a CT myelogram,

34:43

this is not contrast.

34:44

This is all calcification within the fecal sac.

34:47

This is the corn like area of clumping

34:49

of the cau equine of nerve roots.

34:51

Two separate parts. And on mr, these are axial t

34:54

axial sagittal T two sequences, um, that's characterized

34:58

by linear bands

34:59

of hypo intensity within thecal sac corresponding

35:02

to areas of calcification.

35:04

Not good. Now we'll move into

35:09

our last topic here.

35:10

Uh, this is, uh, a favorite topic

35:13

of mine in post-op spine patients.

35:15

It's always a question of infection.

35:18

Um, so here we've got four separate

35:23

diagnoses all in post-op spine patients, uh, all of which

35:28

we see called discitis osteomyelitis.

35:32

Only one of these is, okay.

35:35

So we're gonna go through each of these,

35:36

these four diagnoses now,

35:38

and I will not hold you in suspense.

35:41

I'm gonna tell you what they are on the next slide here.

35:45

So we've got Discitis, VMP reaction,

35:48

proximal junctional kyphosis, and pseudoarthrosis.

35:53

Start with our obvious case of discitis here.

35:57

So this was a gentleman who was seven weeks post-laminectomy

36:00

and represented with weakness.

36:02

He has classic imaging findings of lumbar discitis

36:05

and osteomyelitis with intense and plate

36:09

and discal space edema and plate destruction.

36:13

He has what we refer to as the SOAs sign,

36:16

T two Hyperintensity along saw muscles.

36:18

Um, this is probably a tiny little micro abscess here

36:23

and some ventral epidural flagg mono abscess

36:27

looks terrible on the post contrast sequences with lots of

36:32

epidural enhancing.

36:33

Flagon and abscess prevertebral tissues are also involved.

36:38

And there is of course, the classic moth eaten destructive

36:41

changes of the nplate.

36:47

So the SOAs sign is quite specific on MR for discitis.

36:52

Um, but you know, the truth is in patients

36:55

who are in the recent postoperative period,

36:57

especially the first six weeks,

36:59

there really can be quite a lot of overlap in the normal

37:03

expected, uh, post-surgical changes of the spine

37:07

and patients who are presenting with early discitis, um,

37:11

you know, they've been in there, they're manipulating all

37:13

the soft tissues, everything's inflamed,

37:15

everything enhances.

37:16

Uh, so additional things that we use to our advantage.

37:19

We look for collections outside the surgical corridor.

37:22

This is why it's so important to understand what type

37:25

of procedure the patient has done, has had done.

37:28

And then other things that we can use kind of

37:30

beyond the five to six weeks period is, uh, you know, foci

37:33

of gas that are persisting beyond six weeks.

37:35

That's not normal. You know, nobody should have that.

37:41

Cases of discitis should always be read in clinical context.

37:45

You know, if you don't have any history,

37:46

you gotta pick up the phone and call the referring doc.

37:49

You know, does the patient have fever chills?

37:51

Do they have elevated inflammatory markers?

37:53

Um, and you know, an important point

37:58

to make about image guided biopsy,

38:00

not just in the postoperative patients,

38:01

but um, very low yield, uh,

38:05

less than 50%

38:07

and even lower in patients who have, uh,

38:10

who are not antibiotic naive.

38:12

Um, a negative biopsy does not exclude a diagnosis

38:15

of discitis or osteomyelitis.

38:17

Okay? If you get a bug back, it's great

38:19

and it helps you tailor antibiotic therapy,

38:22

but you're not off the hook if it's negative.

38:26

So, uh, question we get a lot, uh, is, you know,

38:30

whether these patients should be followed

38:32

with surveillance imaging to evaluate

38:34

for treatment response.

38:36

And the answer is of course no.

38:38

And, uh, any ID doc

38:40

with experience treating these patients should know that,

38:42

um, you know, imaging,

38:44

repeat imaging on this patients really happens when there

38:47

are new or worsening symptoms

38:49

or if they have an initial MRI that is equivocal

38:52

and the patient's coming back in a two week period

38:54

to see if there are progressing changes at the end place.

38:57

The reason we don't follow these patients on imaging is

39:00

because the bone changes lag the patient's clinical picture.

39:04

Um, and it can really confuse the picture.

39:08

Uh, you know, oftentimes when patients are re-image,

39:12

you know, we can see, um,

39:13

patient has subsequent vertebral body collapse.

39:16

I mean, the MR looks far worse than it did at the initial

39:19

presentation, but clinically the patient is improving,

39:22

they're having a response to therapy.

39:24

Um, and what we do follow is the soft tissues.

39:27

Um, we look to see for resolution of abscess, resolution

39:31

of flagon and inflammatory changes,

39:33

and that is usually a better marker of treatment response,

39:36

um, than looking at the bony changes which

39:38

can persist for months.

39:42

An important note to make about

39:44

cervical discitis in patients

39:46

who have undergone cervical instrumentation.

39:49

So there is a much lower rate

39:52

of postoperative infection in the cervical spine relative

39:56

to its thoracic and lumbar counterparts.

39:58

And this is because, uh, the neck soft tissues are

40:02

so much more well vascularized than, uh,

40:05

say the lumbar soft tissues.

40:08

So if you see findings concerning for cervical discitis,

40:13

you know, at or near an operative level, either an A CDF

40:16

or a disc arthroplasty,

40:18

it should set off an alarm in your head

40:20

and you must consider a Fargo esophageal perforation.

40:25

This can either happen in the acute setting from direct

40:28

trauma, usually surgical retractors, uh,

40:31

which was the case in this patient here

40:34

who had a hypo pharyngeal perforation, uh,

40:37

following arthroplasty.

40:39

It can also happen in the chronic setting in patients

40:42

who have hardware failure in migration resulting in

40:45

Fargo esophageal perforation.

40:47

This is not an diagnosis that you are going to make on mr.

40:52

Okay, these patients need to go to,

40:54

these patients need esophagus with water soluble contrast,

40:57

either fluoro or ct.

41:00

Um, please remember, anytime you're evaluating for visceral,

41:04

visceral or vascular injury, um, it's crucial

41:08

to have a non-con exam as well.

41:15

So let's move on to our, our next NOC Discitis case.

41:18

Uh, this is a gentleman

41:20

who is six weeks post-op from a two level fusion.

41:24

Um, at week two he developed severe excruciating back pain

41:28

and right lower extremity radiculopathy.

41:29

Didn't get in for imaging right away.

41:32

Um, we can see on his pre-op ct,

41:33

he's got severe lumbar spondylosis,

41:36

he's got inner body hardware postoperatively.

41:38

There's pretty significant increase in sclerosis.

41:40

Some areas of, uh, cystic change osteolysis

41:42

of the pls on mr.

41:45

He's got really intense almost whole over

41:47

body edema at these levels.

41:49

Some prevertebral soft tissue inflammation here,

41:53

this stripe on the stir.

41:55

And then he has, uh, this tiny fluid collection here.

41:58

And, uh, you know, talk to the surgeon.

42:00

This was a right trans so approach.

42:02

So this would be considered outside the surgical corridor.

42:04

So does this guy have discitis? No, he does not.

42:08

This is a great example of B-M-B-M-P reaction

42:12

with inflammatory cyst, uh, like Steve mentioned.

42:16

So BMP was, uh, approved by the FDA back in 2002

42:20

and became very popular, um, due to enhanced fusion rates,

42:24

um, and was being used probably in up to 30%

42:28

of lumbar fusions.

42:30

Uh, following that has since, uh, fallen out

42:33

of favor in some places due to some of these, uh,

42:36

unintended, uh, unwanted complications with BMP.

42:40

And so it's, uh, really honestly kind

42:43

of geographic dependent, um, where it's still used.

42:46

But on CT we can see LAC sclerosis and osteolysis.

42:49

This usually peaks in the six week to six month period.

42:52

This can result in hardware subsidence or migration.

42:55

It doesn't always. And then of course,

42:57

heterotopic bone formation, which

43:00

for some reason is more commonly seen with the TLI approach.

43:03

And then on Mr uh, intense marrow edema

43:07

and these inflammatory cysts, which depending on

43:09

where they decide to arise, can result in neuro compression.

43:14

Um, the other thing you should be aware of in patients

43:18

who have VNP fusion, they can get this intense

43:20

and very symptomatic inflammatory reaction in the first two

43:22

weeks, which is exactly what this patient presented with.

43:28

So now our, our third case of not discitis,

43:31

this was a patient who had a,

43:34

a long segment thoraco lumbar fusion, um, presented

43:37

with back pain and leg weakness.

43:39

So we've got sagittal T one, T two and stir sequences.

43:43

Could see there's a, uh, T 11 burst fracture here

43:46

with complete collapse of the vertical body.

43:48

There's also nplate fracturing at T 10.

43:51

Um, a lot of edema, some fluid within this space here,

43:56

prevertebral soft tissue changes

43:57

and then of course cord compression and it edema.

44:01

This is what this patient looked like on ct.

44:03

Uh, the fact that there's actually gas here is reassuring.

44:07

Uh, it's one of the things that we, uh, look for to

44:11

reassure us that, you know, maybe there's not an infection

44:13

at the disc level there.

44:15

Um, but this patient has proximal junctional failure

44:19

or kyphosis.

44:21

Um, these patients, they get osteoporotic wedge fractures

44:25

and, uh, sometimes with disruption

44:27

of the posterior ligamentous complex typically happens at

44:31

the upper instrumented vertebrae,

44:32

but can also involve the vertebrae ISS just above

44:35

or below that involvement of the pedicles is rare.

44:38

Um, and it's proximal failure.

44:40

They get, um, screw, pullout fluffing.

44:42

You can see here, um, you know,

44:44

these pedicle screws are going right

44:46

through this vertebra body

44:48

and now, you know,

44:50

probably gonna eventually result in

44:52

fracturing of this nplate.

44:53

Um, and these patients have to have at least 15 degrees

44:56

of kyphosis above the instrumented level.

44:59

This is really, uh, a complex and multifactorial etiology.

45:04

Uh, but we know that sagittal imbalance is, uh,

45:07

a important contributor to this.

45:09

That's why we reach so many full spine, uh, x-rays on,

45:13

um, patients like this.

45:15

Um, and other considerations.

45:16

Um, bone quality, you know, osteoporosis,

45:20

sarcopenia like Steve mentioned.

45:21

Um, you know, things that affect a patient's ability

45:24

to support a long segment fusion construct.

45:28

Uh, and that's why, you know, I read out

45:29

of a neurosurgical office every Friday

45:31

and any patient that's getting referred for surgery,

45:33

they get a DEXA scan,

45:35

they get their vitamin D level checked, um,

45:37

the neurosurgeon's looking at the fatty infiltration

45:39

of the dorsal paraspinal musculature

45:41

because this is what they want to avoid.

45:43

Okay, and our last case here,

45:48

uh, this is a woman

45:52

who fell two months ago.

45:54

She's got a lumbar fusion now one down through the sacrum,

45:57

and, uh, she came in with back pain.

45:59

So we can see T one, T two and stir sequences.

46:03

She's got this large fluid cleft here between the T 12

46:06

and L one vertible bodies.

46:07

It's not really in the disc space,

46:09

but there's uh, obviously some destruction of the T 12 body.

46:14

Um, some prevertebral soft tissue stuff not well captured

46:17

here, but I promise you it was there.

46:19

Um, so this is another not Discitis case.

46:23

Uh, this is a nice example of pseudoarthrosis.

46:26

It's a false joint. Uh, our, we see it in, uh,

46:30

fractured long bones, which is essentially

46:32

what the spine becomes when it has a long segment fusion,

46:35

uh, either, uh, instrumented

46:38

or the other example we see this commonly in

46:41

and probably once a quarter, I, I see this in, uh,

46:44

ankylosing spondylitis, ankylosing spondylitis patients,

46:47

older gentlemen who have fallen and they come into the ER

46:51

or an outpatient imaging center two months later

46:53

with a spine that looks like this.

46:56

So it's a fusion adjacent, unstable

46:58

or complete fracture, usually a disco

47:00

vertebral complex injury.

47:02

Um, and they get osteo

47:04

and sometimes intense inflammatory soft tissue changes.

47:07

I promise you this gentleman was not infected.

47:11

This was all pseudoarthrosis.

47:12

We can see this man had ankylosing spondylitis here.

47:15

He's got the bridge bridging syn deses fused,

47:17

uh, supraspinous ligament.

47:20

Uh, and it's a a two, uh, you know, fibular pseudo aosis,

47:24

which our MSK colleagues might be more familiar with.

47:29

So the last thing we'll touch on,

47:30

this is our last slide here.

47:31

Uh, MR is not the modality of choice

47:36

for evaluating hardware in post-op spine patients,

47:39

but oftentimes, uh,

47:41

it might be the first imaging study a patient gets, uh,

47:44

because they're presenting with a new radiculopathy

47:47

or, uh, new neurologic deficit.

47:51

And oftentimes they're looking for, you know,

47:53

recurrent extrusion, um, things like that.

47:56

Uh, and so sometimes we are the first ones

47:58

to make the diagnosis of a hardware failure.

48:01

So we'll just go around the horn here

48:03

'cause these are some nice examples

48:04

and you can make these diagnoses on Mr.

48:07

Uh, starting with number one.

48:09

Uh, this is a migrated inner body spacer

48:12

into the left lateral recess.

48:13

This is impinging the descending left S one nerve root here.

48:16

This patient had left lower extremity radiculopathy.

48:19

Image number two. This was patient who had had an A CDF, uh,

48:24

with new neurologic symptoms, new, uh, myelopathic symptoms.

48:28

And we can see they've got an anterior plate here.

48:32

There's, uh, clear discontinuity, the plate is fractured,

48:35

and the C four vertebral body is retro pulses causing

48:37

cord compression here.

48:40

This four block of images here at all,

48:42

the same patient we've got MR on top, the T two sequences

48:45

and CT on the bottom.

48:47

This patient had, uh,

48:48

left lower extremity radicular symptoms.

48:51

We can see there's this curvilinear area

48:54

of T two hypo intensity here, which you would think nothing

48:56

of except this patient's had a laminectomy.

48:58

The ligamentum has been stripped.

49:00

This is not ligamentum flam, it is in fact extruded cement

49:05

in the lateral recess

49:06

and pinching the descending nerve root.

49:09

And our last case here was a patient

49:12

who underwent a lumbar fusion

49:14

and had postoperatively bilateral L five distribution

49:18

radiculopathy on mr.

49:21

He had susceptibility artifact, uh, you know,

49:24

pretty significant anterior cortical breach, uh,

49:27

going right into both traversing, uh, L five, uh,

49:32

nerves in the presacral area.

49:33

And here's his subsequent ct.

49:36

You can see that's, that's a lot of

49:37

the anterior cortical breach there.

49:38

Okay, so in conclusion, uh, critical

49:42

to understand the surgical approach

49:44

and indications as well as the risks and

49:46

and complications for each type of surgical approach.

49:49

When you're reading postoperative spine cases, you can,

49:53

of course should always be able

49:54

to get diagnostic quality MR imaging on these patients

49:58

with appropriate protocols and modifications.

50:01

And it is important

50:03

to recognize the characteristic imaging features

50:06

of these postoperative complications for the appropriate

50:09

and timely management of these patients.

50:12

We'll stop there.

50:16

Thank you so much for sharing this lecture

50:17

with us today, both Dr.

50:18

Pomerance. Uh, at this time we'll open up the floor

50:21

for any questions from our audience.

50:22

You may submit those through the q and a feature.

50:25

We also just wanted to say thank you so much

50:26

for the lecture today,

50:28

and thank you for participating in our noon conferences

50:31

and for asking great questions,

50:32

which I'm sure will come through here shortly.

50:35

Um, and just a reminder that you can access the recording

50:37

of today's conference and all

50:38

of our previous noon conferences by creating a free account.

50:41

We'll also be emailing out the link

50:42

to the replay later to today.

50:45

Let's see if we have anything coming through.

50:54

Nothing so far. We'll give it just, oh, here's one.

50:57

What are your thoughts on c spine prosthetic

51:00

discs in contact sport?

51:06

You want me to answer that one?

51:08

Yeah, you take that, you're the sports medicine guy.

51:11

All right, thanks. Um, so I would, uh,

51:15

IIII would be against somebody participating in contact

51:19

sport with a prosthetic disc, especially if it,

51:21

if it's functioning well,

51:22

whether it's functioning well or poorly.

51:24

Uh, you know, even though it's, it's the patient is stable,

51:28

there's no guarantee that that's going to be stable.

51:31

If a patient receives a blow to the top of the head

51:34

and, uh, especially in, you know,

51:36

American football now maybe European football

51:39

or soccer, uh, that would be one where it's, you know,

51:42

probably okay, but, uh, we don't advocate people

51:45

with prosthetic discs go back to, uh, contact sport.

51:49

Now on the flip side, we've had multiple NFL players

51:52

that have had single or dual level fusions.

51:55

And if the fusions bridge

51:57

and they're solid, we have sent them back

51:59

to play middle linebacker for the Detroit Lions

52:02

and for the Minnesota Vikings.

52:04

So it, it absolutely does occur after surgery,

52:07

but I certainly wouldn't consider it

52:09

after a, uh, prosthetic disc displacement.

52:14

All right. Any,

52:17

I think this word is prosthetics on prothetic on use

52:21

for lamina after laminectomy.

52:23

Why is it not needed?

52:27

Sorry, what's the question?

52:32

Um, or is it hopping around?

52:36

I mean, it's in the, that one is in the chat.

52:41

I think. I wonder if they're trying

52:42

to ask about laminino laminino plasty following laminectomy.

52:46

Maybe not sure. I'm not entirely sure. No.

52:50

Okay. That another one.

52:52

Um, an acute vertebral collapse in oncologic patients, how

52:56

to rule out metastases fracture metastasis.

53:01

Yeah, I, I I can give a few comments there, Taylor,

53:04

you can speak to it as well.

53:05

Um, first of all, most metastasis like the middle

53:09

and posterior column, so the anterior column

53:13

of the spine is the anterior two

53:15

thirds of the vertebral body.

53:16

So just like you learned as a resident,

53:18

if you've got a destroyed pedicle, you know,

53:21

you gotta worry about metastatic disease.

53:23

Well, where's the pedicle, the pedicle kind of sits

53:25

between the middle third

53:26

and the posterior third, the middle column

53:28

and the posterior column.

53:30

So involvement of the posterior third of the vertebral body

53:33

and involvement of the, uh, of the pedicle, um,

53:37

or posterior third of the vertebral body is a sign

53:41

that you're dealing with something that,

53:42

that may be nefarious.

53:44

Another, uh, helpful point is the shape of the thing.

53:47

You know, if it's round, most metastases are not

53:50

perfectly round fat poor.

53:52

He angios are typically round

53:54

and they often masquerade as metastatic disease,

53:57

but they typically have a little bit of reparative fatty rim

54:01

around them and they will fill in late

54:03

fashion if you inject them.

54:04

So that's another, another potential tip off, uh,

54:07

metastases are gonna mean multifocal, whereas, um, you know,

54:12

some of these other things that you see in the spine are

54:14

usually, uh, uni unifocal.

54:18

And then in terms of enhancement, if, if there's any doubt,

54:21

you can always do a fat suppressed pre

54:23

and post contrast, uh, enhancing study.

54:26

Taylor, any other comments?

54:28

Sure, I'll add, I'll add two more comments.

54:30

So the one Steve mentioned, you know,

54:32

posterior element involvement typically does not happen in

54:34

osteoporotic compression fractures.

54:37

Uh, and the second is, uh, the shape

54:40

of the posterior cortex.

54:41

So, you know, the way I was taught to think about it,

54:43

which I think is really helpful is, you know,

54:45

with say osteoporotic fractures, they collapse

54:48

because there's loss of substance within the vertebral body.

54:51

So everything collapses inward.

54:53

So sometimes you have inward bowing of the cortex

54:55

or, um, you know, it stays, um, you know, flat,

54:59

the posterior cortex of the vertebral body, uh, versus, uh,

55:02

metastasis with pathologic fracture.

55:05

Uh, it happens because the marrow is being replaced by stuff

55:09

and it bulges out.

55:10

So, you know, that's one thing we always look

55:12

for is posterior cortical bowing.

55:15

Occasionally I have seen it in osteo product compression

55:18

fractures, but usually, you know,

55:19

we see it more commonly with mets.

55:21

Um, the other thing of course is, you know, if you think,

55:24

if you're starting to think about mets for a fracture,

55:27

you know, you go on an extensive hunt

55:29

for other secondary findings, you're looking

55:31

for other bone lesions in the pelvis

55:32

and the spine, you're looking at the localizer sequence,

55:35

you're looking for nodal mets, you're looking for, uh,

55:37

a chest mass in the, you know, localizers.

55:40

Um, and that can sometimes be the thing that tips you off

55:44

that what you're dealing with is a met

55:45

and, uh, not a bland compression fracture.

55:47

And sometimes you, you know, you have to look

55:48

outside of the spine too.

55:50

Yeah, I have one more thing to add.

55:52

Somebody with known cancer, sometimes these nplate changes

55:56

can look very ominous and

55:58

whenever I see anything that is linear, you know,

56:01

that is not going to be metastatic disease,

56:03

metastatic tumor doesn't grow in a line.

56:06

And even I've, I've seen people that have had, uh,

56:08

vertebral plasty where, you know, novice radiologists

56:12

or non neuroradiologist confuse that

56:13

with a sclerotic metastasis,

56:15

those are gonna have a unique shape, which is kind

56:17

of starburst or it's going to be very linear.

56:20

So the shape is also really helpful.

56:25

Great. Is there a consideration in hardware imaging

56:28

with dual source ct?

56:32

Well, maybe if you're looking for gout associated with,

56:35

with hardware there, there might be,

56:37

but I think high resolution is tailor indicated,

56:40

high resolution CT for hardware placement for migration,

56:45

for subsistence, you know, that that's gonna do the job.

56:49

I'm not sure that there's a role for it.

56:50

Taylor, do you have any thoughts on that?

56:53

I've never been sent any dual energy CT cases

56:56

to look at hardware, so I'm not sure I,

56:59

I I haven't either.

57:00

I will say this though, any place in the body

57:03

where there's an irritant, gout can go.

57:06

So, you know, gout, gout will go to ligaments, gout will go

57:08

to tendons, gout will go to, uh, prosthesis.

57:14

Alright. Are fractures due to osteopenia categorized,

57:17

categorized as pathological like they are in

57:19

pathology indexing?

57:23

I don't know the answer to that one. We,

57:25

I mean we, we don't typically refer to them

57:27

as pathologic fractures.

57:29

Uh, you know, we say osteoporotic compression

57:34

or insufficiency fracturing, um,

57:37

don't typically include the word pathologic if I'm dealing

57:40

with a bland fracture.

57:41

Yeah, I think, I think what they meant is

57:43

pathologic fracture.

57:45

If there's a met in it, um, you know, i'll us,

57:49

I'll usually say like as you do, you know, insufficiency

57:53

or osteoporotic versus tumor, tumor related

57:56

compression fracture or complicated

57:59

compression fracture with neoplasm.

58:02

Right. And what is your opinion on assessment

58:04

with Dixon in phase versus Dixon out of phase

58:08

for confirmation of atypical hemangiomas?

58:15

I can take that one. Um, that's an easy, easy fix.

58:18

You know, if, if it's fat poor, you're just gonna see a,

58:22

a very bright lesion.

58:23

And sometimes if there's microscopic fat,

58:26

you will see it on the, on the Dixon method study.

58:29

Uh, the nice thing about Dixon is you get

58:31

four different sequences.

58:32

You get fat water, enphase and antiphase.

58:35

And so it's easy to pick up microscopic fat like it is

58:37

with an adrenal adenoma.

58:39

Macroscopic fat should be no problem,

58:41

you shouldn't really need the Dixon method for that.

58:44

Um, it's also great for showing you a completely, uh,

58:47

fat absent hemangioma because you'll see the bright spot

58:52

and absolutely no edema around it.

58:54

You are not allowed to have edema around a he angio

58:56

unless there's been a pathologic fracture,

58:58

which I've seen once in 40 years.

59:02

The only comment I'll make on top of

59:03

that is you should get comfortable

59:07

interpreting marrow lesions without chemical shift imaging.

59:11

It's something that is used a lot, I think,

59:13

in the academic medical setting, um,

59:15

and was used everywhere I trained, um,

59:18

and in private practice less so.

59:21

Um, and so you should be comfortable with some

59:24

of the key imaging characteristics

59:26

that will help you distinguish between hemangiomas,

59:29

you know, even looking for subtle T one internal stippling.

59:32

Uh, well marginated lesions, uh, again, like Steve said,

59:35

no surrounding edema.

59:37

Um, sometimes, you know, uh, a t one bright rim

59:40

around the lesion is usually a reassuring um, sign.

59:45

Um, but I, I would not rely solely on, uh,

59:49

chemical shift imaging, uh, to characterize atypical mangis.

59:53

One, one other, one other thing I'll add that I forgot

59:55

to mention and, and tumor tumor related me metastatic

59:58

evaluation, if it's bright on T one,

60:01

I used to say white is right.

60:02

If it's bright on T one, the odds

60:05

of it being a metastatic lesion are extremely low.

60:08

There are very few metastases that will bleed in the spine

60:11

or melanoma even.

60:13

Uh, when it, when it enters the spine, it's usually kind,

60:16

kind of destructive looking and multifocal.

60:18

So there shouldn't be much confusion.

60:20

If you've got fat signal on a T one weighted image,

60:24

it's not gonna be a metastatic lesion.

60:27

Awesome. And with that, we are at time,

60:30

so we just wanna say thank you again

60:32

to both Dr. Taylor Pomerance and both Dr.

60:34

Steven Pomerance and for this lecture today. It was great.

60:37

And also thanks to all of you

60:39

for participating in this noon conference

60:40

and asking great questions.

60:42

Be sure to join us on Wednesday,

60:43

July 16th at 12:00 PM Eastern time, where Dr.

60:46

Deborah Baumgarten will deliver a lecture entitled case

60:49

review of the Splenic Abnormalities.

60:51

You can register for that@mmrionline.com

60:54

and follow us on social media

60:55

for updates on future noon conferences.

60:57

Thanks again and have a great day.

61:00

Thank you. Thanks Ashley. Bye.