0:02

Hello and welcome to noon conference hosted by MRI online.

0:06

Noon conference connects the global Radiology community Through free

0:09

live educational webinars that are accessible for

0:12

all.

0:13

And as an opportunity to learn alongside top Radiologists

0:16

from around the world, we encourage you to ask questions

0:19

and share ideas to help the community learning grow.

0:22

You can access the recording of today's conference and previous new

0:25

conferences by creating a free Mr. Online account.

0:29

You can also sign up for a free trial of our premium membership to get

0:32

access to hundreds of case-based microlearning courses across all

0:35

key Radiology for specialties.

0:38

Today we are honored to welcome Dr. Lee. Al-halali for

0:41

a lecture on Mr. Neurography of the cranial spinal

0:44

nerves below the skull base.

0:46

Dr. Al halali is a neuro radiologist and currently

0:49

director of neuroradiology at the ivy brain

0:52

tumor Center.

0:53

Her research focus is on novel Imaging techniques and

0:56

focus ultrasound and brain tumors, but her

0:59

clinical love has always been on skull base anatomy and pathology.

1:03

The desire to see more and know more has led her to pursue high resolution.

1:06

Imaging of the skull base it helped to visualize

1:09

the anatomy. She has grown to love Dr. Al halali

1:12

also has a deep passion for Open Access education and

1:15

you can follow her on Twitter at teachplaygrub to

1:18

learn more from her.

1:20

She believes there's no greater impact. She can have than using

1:23

education to help other Physicians take excellent care

1:26

of their patients.

1:27

We couldn't agree more Dr. Alhali and are thrilled you're

1:30

here today to share your expertise at the end of the lecture, please

1:33

join her in a Q&A session where she will address questions you

1:36

may have on today's topic.

1:38

Please remember to use the Q&A feature to submit your questions so we can get

1:41

to as many as we can before our time is up. And with that. We're ready

1:44

to begin. Today's lecture Dr. Al halali. Please take it from

1:47

here.

1:48

Thank you so much. It's really an honor to be here. And

1:51

I really want to thank MRI online for inviting me

1:54

and giving me the chance to share some of

1:57

my love of anatomy and Advanced Imaging with all of you.

2:00

Today, I'm going to talk about Mr. Neurography of the cranial spinal

2:03

nerves those below the school days.

2:05

I have no disclosures I long for a day

2:08

where I have a long list of wonderful disclosures of people paying me much

2:11

money but not today.

2:13

So when we're talking about mine orography at

2:16

the skull base, the first thing we're going to talk about is the technical considerations.

2:20

The cranial nerves are different than all the

2:23

other nerves that we usually image with traditional MRI

2:26

neurography techniques. So you need a special technique

2:29

to be able to visualize these incredibly small

2:32

nerves. It's just like, you know, if we're talking about the brachial plexus

2:35

versus the school days, you're not going to have the same, you know

2:38

traditional Imaging of the shoulders you will for the

2:41

brain. So the same way you won't have the same Imaging for

2:44

the brachial plexus Mr. Neurography as you will for

2:47

the neurography at the skull base.

2:50

Then one of the big uses of Mr. Neurography

2:53

is for pain syndrome, and I'll talk a little bit about

2:56

how I use that to basically help diagnose difficult

2:59

in a typical facial pain syndrome.

3:02

And then finally some Advanced uses of

3:05

mineography is actually to help our skull base.

3:08

Neurosurgery colleagues to better plan school-based surgeries.

3:13

So let's first talk about a little bit of background.

3:16

So let's talk about peripheral neuropathies. They're actually a very heterogeneous

3:19

group of disorders. The way I look

3:22

at it is the nerve is kind of the connection between the spinal

3:25

cord and the muscles the same

3:28

way bungee cord kind of connects you between the ground

3:31

below and a cliff and many things can

3:34

interrupt you on your way down trauma tumor

3:37

compression infection and

3:40

you know radiation therapy

3:43

many things anything that interrupts your travel from

3:46

the top of your Hill to the bottom. I

3:49

can possibly cause disruption of the nerve and

3:52

a peripheral neuropathy.

3:54

But yet despite having an incredibly heterogeneous group

3:58

of pathologies that can cause a

4:01

peripheral neuropathy. They actually all look very

4:04

similar when we get down to EMT studies and

4:07

I'm kind of like to compare it to doing

4:10

Mr. Spectroscopy. You have tons of

4:13

different pathologies when it comes to them our spectrosity, but

4:16

in the end the Spectrum all looks like decreased NAA

4:19

increase choline.

4:21

Similarly, there's this very diffuse spectrum

4:24

of peripheral neuropathies for which

4:27

you really kind of get only two basic findings

4:30

on the EMG, which is the myelinating and external pathology.

4:33

So we really have a

4:36

gap that needs to be filled in helping

4:39

to diagnose these disorders for our clinical

4:42

colleague. And and this is where Mr. On your feet comes

4:45

in, you know the same way Mr. And the traditional Imaging can

4:48

help you differentiate, you know, all these different pathologies away a

4:51

spectrum can't you know, imagine if you had a diagnose all your

4:54

brain tumors just based on a Mr. Spectroscopy of the lesion it

4:57

would be impossible. So the anatomic imaging has an

5:00

incredibly critical role in the diagnosis

5:03

and care of these patients.

5:05

So traditionally cross-sectional Imaging could only demonstrate

5:08

a mass compressing the nerve externally, but

5:11

with the continued advance

5:14

of Mr. Techniques we can now actually look for intrinsic pathology

5:17

in the nerves. I like to use the

5:20

analogy of it's like going from you know, basically like Periscope right?

5:23

Just lets you see that there's something there versus a microscope

5:26

actually being able to look inside the

5:29

tissue and being able to see the intrinsic

5:32

pathology inherent in the

5:35

nerve.

5:37

So, how do we do?

5:38

So I like to use the analogy that

5:41

it's kind of like Mr. Neurography

5:44

is for nerves the way Mr. And

5:47

geography is for vessels. The whole purpose is

5:50

to basically get rid of the background noise

5:53

and the background signal in order for

5:56

you to be able to visualize the nerves. So they're

5:59

very different techniques from a you know, Mr. Physics

6:02

standpoint, but luckily for you. It's not an MR

6:05

physics lecture, but the point is that you're using

6:08

the same principle of knowing the background

6:11

so that you're better able to see the object that

6:14

you're looking at for our concerned with so Mr.

6:17

Neurography you want to look at the nerves just like Mr. And

6:20

geography you want to look at the vessels.

6:22

So let's talk about how we do that.

6:25

So Tim Willett says I mentioned similar to

6:28

angiography. We want to know the background in order

6:31

to be able to see the nerves. So traditionally for

6:34

larger nerves like the brachial plexus. We

6:37

did this using first a fat saturation

6:40

technique and to get rid of like the bones the

6:43

subcutaneous fat and then we would

6:46

do a black blood technique to remove the signal from

6:49

the vessels so that basically all we

6:52

are left with are the nerves and you know, a few small lymph

6:55

nodes.

6:57

Unfortunately those type of

7:00

technique that works so well for large

7:03

nerves like the brachial plexus don't actually

7:06

have the spatial resolution to help

7:09

us to visualize the cranial nerves at the skull base.

7:12

So what we do is we use a reversed

7:15

steady state free procession

7:18

technique. So everyone knows the traditional

7:21

steady state free procession technique, which

7:24

is the Fiesta Imaging which we used to look at the cranial nerve inside

7:27

the cranial ball. Now, we

7:30

just reverse that technique to be able to look at

7:33

the cranial nerves.

7:34

Outside the cranial Vault. So the Siemens

7:37

name for the

7:40

fiesta Imaging or steady state reprocession

7:43

is fifth.

7:45

And so they just literally reverse the letters. It doesn't stand

7:48

for anything. They just literally reverse it. And so it's called a psif.

7:51

So I guess we're lucky that he eat

7:54

an invented because that would be called a atsie f

7:58

or reverse Fiesta. And so

8:01

it's it doesn't actually say anything but it's

8:04

literally just a reversed study State Precision sequence.

8:09

So our protocol to look at the cranial nerves

8:13

of the school days is we use the 3D psif sequence.

8:16

We do it on a 3T because

8:19

we need to get incredibly small spatial resolution

8:22

and we need to keep our time to reasonable

8:25

because we don't want the patient to be moving. We use

8:28

a 32 Channel head coil. It doesn't get as good deep penetration

8:31

into the brain but a lot of these nerves are

8:34

relatively superficial. So a 32 Channel head coil will

8:37

help save you on time and won't decrease your your image

8:40

quality for The Superficial nerves. We do

8:43

point five millimeter isotopic voxels and on

8:46

a 3T full of scanner that turns out to be about it

8:49

six and a half minute acquisition all of the images. We

8:52

look at on a 3D separate workstation in

8:55

order to make multi-planner and curved multiplayer formats

8:58

of the nerve.

9:00

And then in addition to our psif sequence, we

9:03

also do axial T1

9:06

weighted images and coronal stir images. I'm

9:09

in order to look for other things that may be causing peripheral neuropathy.

9:13

Remember it's it's not always intrinsic pathology right?

9:16

We're at the school base. There's still a lot of perinural spread

9:19

of tumor. So you want this T1 weighted images to

9:22

be able to make sure your fat planes are all preserved around your nerves

9:25

and then of course the colonel stir images are helpful

9:28

to look for any sort of muscle signal

9:31

and the t1-14 muscle

9:34

atrophy that may be a result of any sort of

9:37

nerve injury.

9:39

So we actually literally will trace

9:42

the nerve on our curved multiplier

9:45

reconstructions to kind of lie it out along.

9:48

Its course the same way that many people in

9:51

see the antiography will lay out

9:54

the Carotid along its course, which is really helpful because

9:57

a lot of times you're trying to figure out if the nervous thicken

10:00

so it's helpful to be able to look at the region you think

10:03

is thickened next to a more normal appearing

10:06

region, right? It's almost like a Nathan right you want to

10:09

compare the region of stenosis or enlargement for nerve

10:12

with a more normal region?

10:15

So the big application of the mrnography that's

10:19

called base is basically for craniofacial pain

10:22

syndrome. The biggest of these is obviously going

10:25

to be trigeminal neurology dwarfs any other pain syndrome

10:28

in terms of the population that

10:31

has it. But also there can

10:34

be glossopharyngeal nerve syndrome

10:37

gossiparyngeal neuralgia. And of course

10:40

civil around is a big problem in the headache population

10:43

as well.

10:45

So some novel uses that we're trying to use to

10:48

apply this mrnography is for more

10:51

untraditional pain syndrome. So

10:54

video nerves the cluster headache syndrome is

10:57

looking for pathology in the region of the vidian nerve because

11:00

it has a more autonomic sort of cluster headache.

11:04

Symptomatology and then one of the important things we're

11:07

using it for is with our school-based surgeons to help inform their

11:10

operative approach being able to visualize the facial nerve

11:13

or prodded syndromes being able to determine if

11:16

you have a post-style a paraphernal space Mass which nerve it

11:19

may be a rising from and then of course just to

11:22

help them counsel the patients about how close their tumor may

11:25

be improximity to specific nerves to help them better inform

11:28

and make a better operative decision.

11:32

And then of course, we also have used it. I'm

11:35

in patients where we're concerned about Perry nelsprout tumor, but for whatever

11:38

reason the patient cannot receive

11:42

Okay, so let's talk about the big use of

11:45

cranial space neurography, which

11:48

is for pain syndrome.

11:51

So to understand looking for pain

11:54

syndrums on mrnography, you have to understand. What

11:57

is pathologic in a

12:00

nerve on MRI. What?

12:02

Constitutes brain injury or sorry

12:05

nerve injury. So I like to think of the nerves kind

12:08

of like you think of vessels, right? So nerves

12:11

are carrying information or sensory

12:15

or motor to muscles nerves Etc

12:19

the same way your vessels are

12:22

blood to your brain. So anything that's going to interrupt this

12:26

delivery of information the same way if you interrupt blood

12:30

flow to the brain will cause damage to the end organ and so

12:33

in the case of nerves it would be muscle muscle atrophy

12:36

and in the case of a vessel, it would be

12:39

the brain.

12:41

So, you know the whole idea

12:44

is when you have enough damage to

12:47

a nerve you get and organ

12:50

damage in terms of denervation changes of the

12:53

region that it's supposed to be supplying the same way you get and Normand

12:56

damage like a stroke if you decrease the blood flow

12:59

enough.

13:00

To that region at the brain. So I really like that

13:03

whole analogy of they're just Delivery Systems

13:06

the same way the vessels are Delivery Systems for

13:09

blood

13:13

So the most common classification to Mr. For

13:18

nerve injuries of Sunderland classification.

13:21

Now this is actually a pathologic classification for which

13:24

we do have corresponding finding

13:27

fun and minority.

13:29

So the class one the most mild injury on

13:32

the Sunderland classification is basically it's called neuropraxia. And

13:35

it's basically where some injury to the myelin. It's

13:38

like a punch in the face like a nerve bruise is the

13:41

way I think about it.

13:42

So in terms of like the analogy in

13:45

terms of vessel is kind of like, you know a carotid.

13:48

Plaque right and there's damage to the endothelium, right? That's

13:51

how we got the crowded plaque. But you know, everything else is

13:54

intact. They're still plenty of flow everything looks good. And so

13:57

the nerve can show increase T2

14:00

signal and you know

14:03

from a demo like being bruised but there's no effect

14:06

on the end Oregon the muscle because we still

14:09

have plenty of you know, the equivalent of flow right? It's just

14:12

a nerve root.

14:14

The next classification Class 2 and 3

14:17

is when there's actual disruption of the axon

14:20

itself and the myelin but the

14:23

stuff around it the perineurium the epineurium are preserved.

14:27

And I like to think of that it's kind of like a dissection. So it's

14:30

not now we've actually interrupted, you know,

14:33

the endothelium but everything else the

14:36

media the adventitia that's still intact. So

14:39

we've gone to Step Beyond just having you know kind of like irritation

14:42

information actually disrupted it.

14:45

And for this we can see increased signal and increase size

14:48

and because now, you know the same

14:51

way we're now starting to interrupt the flow, you know, it's not just

14:54

the plaque where it actually have like a dissection that can be throwing, you know, embly we

14:57

will see end organ changes. And

15:00

so we'll see denervation changes in the muscle.

15:05

So class four is when you actually have full

15:08

disruption, but only the epineurium is

15:11

intact the perion as well as disrupted.

15:14

And I'd like to think of this kind of like as a pseudo aneurysm, right?

15:17

What is a pseudo aneurysm except, you know,

15:20

essentially a contained rupture.

15:23

And and this is essentially what it is. It's a contained

15:26

rupture of the nerve. So you'll actually see it focally

15:29

enlarged the same way. You would see a focal enlargement

15:32

with a pseudo aneurysm and because again,

15:35

we're now disrupting flow right? We're

15:38

just roughing the flow of information. We basically ruptured the

15:41

nerve and then you will see denervation in

15:44

the muscle on MRI neurography.

15:49

Finally the most serious injury is when you actually fully disrupt

15:52

everything and you basically get an end bulb.

15:55

Neuroma. I think of this is kind of

15:58

like thrombosis. You completely closed it off right there.

16:01

There's no more flow.

16:03

You can see as a result some will

16:06

learn to generation of the nerve discs at this point. And of

16:09

course because you've completely thrombosed and

16:12

close it off. You will also see the denervation changes

16:15

in the muscle.

16:18

So let's talk a little bit about the specific nerves

16:21

that we look at and the

16:24

pathology that can affect them.

16:26

So the big one the overwhelming one, I would

16:29

say 90% of the referrals that I get for Mr. Neurology

16:32

are for patients with trigeminal neuralgia and

16:35

facial pain syndrome.

16:37

So the tridal nerve is a mixed sensory and motor

16:40

nerve and it exits the ponds and then after it

16:43

goes through Michael's cave it triforcates into its three divisions

16:46

V1 ophthalmic B2 maxillary and

16:49

V3 mandibular.

16:51

So the ophthalmic Division and exits the

16:54

superiorable fissure and then branches into frontal lacrimal

16:57

and NASA cilio branches. So I

17:00

like to remember that because what's around the orbit,

17:03

right? This is the optimal right? Well, you have your frontal

17:06

bone, right your forehead and along the medial aspect

17:09

of your nose and on the lateral aspect of your laughable

17:12

plan. So that's your three branches frontal black males is

17:15

silvery and these regions innervate basically

17:18

the orbit and the forehead and that's where

17:21

you get your sensation.

17:23

So on Mr. Neurography we can actually see these nerves

17:26

so we can actually see V1 going

17:30

through the superior orbital fissure and you can see here

17:33

on the images. We can actually see it branching into the

17:36

frontal nerve and then the trunk that will give off

17:39

the needs of ciliary and lacromal nerves.

17:41

And along the inferior aspect of the image, you can see the ocular

17:44

motor nerve in this region as well.

17:48

So when we're talking about pathologic processes that

17:51

we're going to be looking at for view one. It's obviously

17:54

a close continuity of sinus. So sinus infections can

17:57

possibly affect it. And again, you

18:00

can see perineural spread of tumor, especially for skin cancers

18:03

that affect the forehead region and it's really

18:06

rare to get a schwannoma in.

18:10

This area next we have V2.

18:11

V2 goes out for I'm in rotundum and the enters

18:14

the terrigal health impossible where

18:17

it gives off basically branches the palette and the alveolus of

18:20

the magazula and then

18:23

it traverses along the inferior aspect of

18:26

the orbit in the infer orbital Canal is the infer orbital

18:29

nerve and then terminates in the skin there and basically

18:32

provide sensation to the mid face.

18:35

So on Mr. Neurography we are actually able

18:38

to visualize the micro anatomy of

18:41

this nerve so you can see here. We can actually identify the

18:44

maxillary nerve going into the

18:47

terrego Palatine Gangland. You can actually see a

18:50

little bit on this image the Palatine nerve

18:53

extending inferiorly from that terrigal palette thinking land.

18:57

We can also Trace out the inferiorbital nerve

19:00

along its entire course. It is incredibly common

19:03

to see and facial skin

19:06

cancers have their perennial spread along

19:09

the infer orbital nerve and this is an example of

19:12

one of those curved multiplayer reconstructions that use in

19:15

order to trace out the nerve over its entirety.

19:20

One of the things that really made me

19:23

fall in love with this technique with the

19:26

amount of detail that you can see on

19:29

this we can actually see the individual

19:32

nerve to each of

19:35

the teeth in the maxilla and I

19:38

was showing this image actually to one

19:41

of the neurosurgery fellows.

19:44

who works in the anatomy lab and he said to me he was

19:47

like

19:47

this is what I see, you know,

19:50

and it kind of reminded me

19:53

of the you know seen in

19:56

Jurassic Park where the paleontologist finally sees

19:59

like, you know, the she had the

20:02

the dinosaurs come to life. It was like this. He's been working

20:05

in this anatomy lab looking at these could ever and now he gets

20:08

to see everything. He's been seeing on

20:11

the cadaver in real life in real people

20:14

and able to see the pathology affecting them

20:17

in life.

20:20

So again similar to V1 the

20:23

max learner of close

20:26

proximity to the sinuses can be infected by sinusitis malignancies

20:29

of the hard palate.

20:32

There's a lot of

20:34

minor salivary glands in the hard palate that have

20:37

a tendency to be things like adenocystic again have perinural

20:40

spread of tumor. One of the things that we do get

20:43

consulted on is if you have a fracture of the orbital floor that

20:46

involves the infer orbital canal and then you

20:49

can cause injury to the infer

20:52

orbital nerve and get paresthesis in that

20:55

region. So looking for injuries of that nerve related to Prior orbital

20:58

blowout fractures and similar

21:01

to V1. It's very rare to

21:04

have nor cheek tumor.

21:05

Finally the mandibular Division and it

21:08

provides some three basically to the mandible lower

21:11

faith and also motor to the

21:14

muscles of mastication. So it excess out

21:17

for through frame of Valley. The motor branch is

21:20

actually very small Branch relative to the sensory portion of

21:23

the nerve and then it gives off The Irregular temporal nerve

21:26

the lingual lingual nerve and then the

21:29

inferior alveolar

21:31

So The Irregular Tumblr is basically sensation around the

21:34

temporomandibular joint and ear the lingual nerve

21:37

joins with the cord attempty to provide sensation

21:40

and taste to the tongue and then

21:43

the inferior alveolar nerve is basically it gives

21:46

off some motor to the floor of milk and then

21:49

the sensation for the gingiva and Teeth of

21:52

the Mand.

21:53

Ible it exits. Finally out the front of the mandible in the mental

21:56

foramen and supplies sensation to the chin

21:59

and lower lip.

22:01

So we can actually see all of these branches the trigeminal

22:04

V3 branch is actually the thickest branch

22:07

and one of the easiest ones for us to actually be able to visualize so

22:10

you can see here on this anatomic drawing the

22:13

Oracle temporal going laterally and then the inferior alveolar

22:16

in the lingle kind of looking like two like

22:19

Stickman legs going down and we can actually see exactly

22:22

what we see on the anatomy drawing.

22:25

On our Mr. Neurography

22:29

so the lingual nerve and the inferior avioliner kind

22:32

of travel and

22:33

in parallel with the lingual nerve

22:36

going towards the tongue and the inferioravioolan are going towards the

22:39

mandible and we can actually see that kind of

22:42

Forked appearance that you see anatomically we

22:45

can see it also on

22:48

Mr. Neurography.

22:51

So the things that can infect V3 is adoptogenic

22:54

infections extending into the inferior alveolar

22:57

canal.

22:58

Anything that injures the mandible can injure

23:01

the inferior alveolar nerve the Imperial Canal so

23:04

fractures osteotyprosis.

23:06

And I would have to say that one of our

23:09

biggest and referral bases is

23:12

pain after tooth extraction due

23:15

to injury of the inferior learner

23:18

from two extraction from dental procedures. And

23:21

again, the gingiva is

23:24

very close contact with the mandibular aviolus.

23:27

And so you can definitely have involvement by

23:32

at malignancies in that region and it is rare to have

23:35

schwannoma.

23:37

So here's some example cases. So this is a

23:40

young woman who had five months of kind of difficulty eating and kind chewing

23:43

with paresthesia's along her lower lip

23:46

after a third molar tooth removal and here

23:49

you can see that the inferior alveolar nerve on

23:52

the right is incredibly bright compared to

23:55

the left. You can see it. It's not per se and large and maybe

23:58

a little bit and but you can see the difference in

24:01

the signal between the abnormal right side and

24:04

the normal contralateral side where the nerve is only, you know

24:07

slightly lighter than the adjacent muscle. So this was a

24:10

Sunderland type one injury.

24:13

This is another example. This was an elderly woman

24:16

who had pain kind of over the left pre-tagus and

24:19

cheek after a left first mandibular molar extraction

24:22

and you can see that we did a ton

24:25

of Imaging over over many many years.

24:28

I mean like I think like we went down to like yeah and like

24:31

1997 all the way up to like 2018. We

24:34

were Imaging her. She had this constant pain. No one could figure it

24:37

out or even doing, you know, traditional Mrs of

24:40

the orbits and face trying to look for the source for pain and but

24:43

we can never find it. So finally when we started doing this

24:46

the ENT who had been seeing her for all these years just like oh

24:49

my gosh, I have the patient for you. We need to look at her.

24:52

so

24:53

you can see here that the normal

24:56

inferior alveolar nerve so that normal forked appearance of

24:59

the lingular nerve are sorry the lingual nerve above it

25:02

and the normal Imperial nerve on the topologic side.

25:05

You can see that you have this thickening of

25:08

that proximal inferior alveolar nerve with

25:11

kind of very fitting almost it's very difficult

25:14

to see actually the nerve distal to this region.

25:17

And so this is essentially an end bulb neuroma

25:20

and and of the

25:23

inferior alveolar nerve that was causing.

25:25

for pain

25:28

And the video nerve so the video nerve

25:31

and is involved in cluster headaches. In

25:34

fact, they used to be called video neuralgia before they

25:37

got more fancy name. So one of

25:40

the things is we can actually see the vidian nerve

25:43

itself on these Mr. Neurography images.

25:46

So you can see here that the video nerve is

25:49

the thin line going through the video Canal right below right

25:52

above it. You see that line above it. That's the that's V2

25:56

and Freeman rotundum. So they're kind of like stacked so

25:59

V2 and permanent below at the video nerve

26:02

and you can actually see that on this anatomic image

26:05

from a cadaver. You can see the thicker V2 on top

26:08

and then the very thin video on the bottom, but it's it's incredibly

26:11

thin but we can actually still see it

26:14

with our Mr. Neurography techniques.

26:18

Okay, occipitalone around that we get

26:21

a lot of referrals from the headache clinic for patients with

26:24

occipital neuralgia.

26:25

So the big nerve that we are really concerned about

26:28

is the greater occipital nerve the greater. Oxidal nervous.

26:31

Actually the thickest cutaneous nerve in

26:34

the entire body. It arises from C2 and basically

26:37

goes along the posterior aspect of your occiput and

26:40

extends over the top of your scalp

26:43

providing sensation. There's also the Lesser occipital

26:46

nerve and the least oximetal nerve

26:49

but they are they're actually much more difficult to visualize

26:52

by mine orography.

26:54

We can see a lot but we can't can't quite

26:57

be everything.

26:59

So here is images of the greater occipital

27:02

nerve. And so this is just a saudible image showing

27:05

it arising from that dorsal ganglion of

27:08

C2 and extending posteriorly along the suboxidal muscle

27:11

to rise along the scalp to to

27:14

provide innovation in that region. So you do

27:17

like the direct coronal you can't always see it

27:20

quite the entirety of the nerve. So that's

27:23

why we really do like to do here's an example of that multi-planer

27:26

curved reformat in order

27:29

to lay that nerve out in its entirety and be able

27:32

to see the entire length of the

27:35

nerve and be able to compare thicknesses signal among

27:38

different regions of the nerve.

27:42

The hospital nerves and

27:45

can be affected by compression points. That's the

27:48

most common finding for patients with occipital moral

27:51

neuralgia. And you can sometimes get occipital region

27:54

lymphatinopathy, but that's rare unless you have a skin cancer

27:57

of the scalp. No, she's tumors relatively rare

28:00

and malignancy also rare So and

28:03

in clinic they can Target these with botox. They

28:06

can actually do it just by clinical palpation

28:09

of landmarks. And we also can do

28:12

it ourselves as Radiologists using image Guidance

28:15

with CT or ultrasound.

28:19

The important role that Mr. Neurography

28:22

plays in these patients because they already know they

28:25

have oxy.

28:25

General neuralgia

28:26

is being able to identify that the

28:29

disease is unilateral

28:32

because if they're going to have decompressive

28:35

surgery and they only decompress one

28:38

side, but it's actually a bilateral neurologist the

28:41

patient won't be health.

28:43

And it's very difficult to tell like

28:46

it's truly one-sided or

28:49

not. Clinically because there can be a lot of referred pain to the opposite

28:52

side.

28:53

Another thing that we can help them with is if there is continued or

28:57

recurrent pain after surgery we can

29:00

tell them if there's perhaps adhesions or you know

29:03

muscle I've hurt you that may have caused recurrent

29:06

compression and they might need another decompressive surgery.

29:10

I can also look for if they cause a post-oper neuroma

29:13

on their own from post surgical

29:16

injury to the nerve.

29:19

So where does the greater oxidal nerve get compressed? Where

29:22

should you be looking for?

29:23

So the greater oxidal nerve sits like

29:26

a little p and a pod between the multivitous muscle

29:29

and the semi-spinaitis spinalis capitis.

29:33

So right in between those two that sandwich

29:36

right there that that fat is

29:39

where your Ox greater occipital nerve is and where it can

29:42

be compressed.

29:43

So what we are looking for when we're doing Mr.

29:46

Neurography of the nerve it's oftentimes. We may

29:49

not see the compression. It can be somewhat positional related

29:52

to the muscle position, but we can look

29:55

and try to see if there is a difference between the

29:58

two nerves and make sure that that

30:01

there is a symmetry to confirm utilateral disease

30:05

so you can see here that on the patient's right.

30:08

It looks fat and thickens right and it's got

30:11

a little pot belly on us, right? It's a very thick and

30:14

nerve work compared to the very thin normal side. And

30:17

so we can tell them that yes, there is

30:20

a symmetry. It looks like it is unilateral disease

30:23

and that will give them confidence that a

30:26

unilateral decompression will be enough to help this

30:29

patient.

30:32

So I'd like to end on what we're really trying to

30:35

push and use this Mr. Neurography

30:38

for which is preoperative planning for our

30:41

skull base surgeons for school-based tumors in

30:44

particular.

30:46

And we also want to use it for our ENT surgeon

30:49

and for parotid surgeries.

30:52

So the facial nerve is the you know

30:55

Achilles heel of prodded surgeries

30:58

and injury to it can be relatively devastating

31:02

to the patient and in terms

31:05

of quality of life and it's the

31:08

reason that a lot of times, you know, we don't want to do anything percutaneous

31:11

in the product because we're afraid of hurting the facial number.

31:14

So the facial nerve is predominantly for

31:17

the muscles of facial expression. It comes

31:20

out the style of mastoid Freeman. It gives off the

31:23

Oracle temporal nerve and then advantages into its

31:26

two major branches the temporal facial to find the temporal and

31:29

facial region in the historical facial, which is the lower facial region.

31:34

So we can actually see this branching. So if

31:37

you look here at the top image, you can see you can

31:40

actually trace the facial nerve as it comes down out of

31:43

the Stylo Master agreement and it makes an Abrupt turn

31:46

to give off that temporal facial branch and then

31:49

lower down. It gives off these cervical facial

31:52

Branch as well.

31:55

So deep and divide into what we traditionally

31:58

remember as the branches of the facial nerve

32:01

the temporal zygomatic Buckle margin mandibular

32:04

and cervical we all remember from med school

32:07

to Zanzibar by motor car. Right? It's one of

32:10

the few med school demonics that's still

32:13

useful. Right and you know, you ain't using the Krebs cycle

32:16

anymore. So it's good that something you memorize in medical

32:19

school is going to be helpful to you and we can see

32:22

each of these individual branches and not

32:25

only can we see the branches we can see the

32:28

branches of the branches. So here

32:31

you can see this trifurcation here of the

32:34

zygomatic nerve along the zagomatic arch

32:37

and male are eminence.

32:40

I'm here. You can see this very distal bifurcation of

32:43

another branch of the zygomatic portion

32:46

of the facial nerve.

32:49

Here you can see the Buckle nerve and you can

32:52

see here the same Pitchfork tryification that

32:55

you can see on the anatomic

32:58

images. You can also visualize on the Mr.

33:01

Neurography itself. So we are able to visualize

33:04

the incredibly distal portions

33:07

of these branches of the facial nerve.

33:10

So no matter how peripheral your lesion is

33:13

in the product we can see what facial

33:16

nerve branches are near or what facial and our friends.

33:19

It's possibly involving.

33:21

The most commonly injured branch of the

33:24

facial nerve in prodded surgeries is the marginal mandibular

33:27

Branch, you know, it's it's kind of a forgotten

33:30

Branch except when it gets injured and we can actually visualize it

33:33

it's incredibly small compared to like the zygomatic portion.

33:36

We can still visualize it and even visualize its individual

33:39

branches as well.

33:42

So the big thing for the facial nerve is

33:45

obviously the parotid product injury

33:48

from product surgery. And then of course the produced

33:51

themselves may also involve it and have paranormal

33:54

spread of tumor.

33:56

The lower cranial nerves for skull

33:59

base tumor removal is also what

34:02

we want to be able to apply this technique more to

34:06

So we can actually see the incredibly

34:09

complex Anatomy at the

34:12

skull base both the

34:15

vascular anatomy and the

34:18

cranial nerve him Anatomy that

34:21

is in that region of the jugular brain

34:24

and in particular so you can see here. We can actually see the

34:27

glossopharyngeal and we

34:30

can actually trace it along the styloid process

34:33

especially in patients have Eagles syndrome, but again, and it's

34:36

an important.

34:39

Nerve to be able to identify when they're doing surgery at

34:42

the school basis, especially in the regional Cellular

34:45

Payment. We can visualize the vagus nerve

34:48

and as well and the vagus number is

34:51

much larger a little bit easier to visualize than the glossopharyngeal nerve.

34:56

And not only can we identify the vagus nerve

34:59

itself. We can actually see its individual

35:02

branches after the Vegas exits this

35:05

the jugular frame and it gives off The Irregular

35:08

Branch going Coast yearly we can actually see this as

35:11

well and then trace the Vegas starve down through

35:14

the school days. I will tell you that we have

35:17

tried to trace the current dealer. We did

35:20

I go for that. It's actually quite difficult just due to

35:23

the respiratory motion, but at the

35:26

school days we can visualize the biggest with extremely good

35:29

accuracy.

35:32

We can also visualize the hypoglossal nerve

35:35

you can see here. This is where it's exiting through the hypoglossal

35:38

pyramid and where it swings

35:41

around to join the lower cranial nerves and the Carotid space before

35:44

moving anteriorly to the times you can see we can take it all

35:47

the way on our curve multiplanary formats from the hypoglossal

35:50

canal out along around through the

35:53

Carotid space as it turns and now it's

35:56

going to be going kind of out of plane here into the tongue itself.

36:02

We can actually even visualize the

36:05

sympathetics in this

36:08

region so we can actually identify the superior cervical

36:11

ganglion in this region, which is

36:14

important because you know, we we talk about

36:17

all these named nerves and we're all concerned about the cranial but there

36:20

can also be a lot of morbidity resulting from

36:23

damage to the superior cervical ganglion and

36:26

and hopefully maybe you know

36:29

as this technique becomes more commonly used and

36:32

more commonly understood. This is the type of thing that we can look

36:35

for when they have a corner syndrome, you know, can we actually visualize

36:38

the cervical gangly and damage to that region? So

36:41

this is the thing that this I just absolutely love

36:44

being able to look at

36:47

these images and feel like I'm looking at an

36:50

anatomy textbook, you know, and being able to see these

36:53

structures that I've always learned were there,

36:56

but had always had to infer

36:59

And pathology with them but now I can actually see

37:02

them and identify pathology in them.

37:06

We can even visualize the accessory nerve. This

37:09

is incredibly important because the most common

37:12

cause of damage to the

37:15

accessory nerve is from percutaneous lymph

37:19

node biopsies.

37:21

So if we are able to help the interventionalist by

37:24

pre-procedurally telling them

37:27

where the accessory nerve is in relation to what they

37:30

want to biopsy that can potentially help save

37:33

a lot of unnecessary andature

37:36

injury at to the

37:39

snow.

37:40

Additionally one of the biggest causes of

37:43

morebidity after a radical neck or

37:46

even a modified neck dissection is

37:49

injury to that accessory nerve and getting that kind of

37:52

shoulder sag from the the damage to the trapezius. So

37:55

if we can better tell the surgeon ahead

37:58

of time whether or not a sacrifice of the accessory nerve

38:01

is necessary. Is there involvement of the accessory in

38:04

our by the lymphatinopathy that might help them

38:07

to kind of if there's no involvement be very very

38:10

clear away from that region and possibly avoid further

38:13

injury in that region.

38:16

So thank you so much for coming to

38:19

my ad talk and I am

38:22

so incredible honored to be here. I just wanted to thank Z King

38:25

Lee. He was one of the Mr. Physicists who really helped us to get this sequence

38:28

off the ground

38:31

and of course my school day surgeon collaborative and little

38:34

and Griffin Centralia and John Mulligan who are the ents who

38:37

have invested a lot in both getting me and patients and

38:40

and giving me clinical feedback about the

38:43

The the accuracy of this technique

38:46

there. So they've all really helped to bring this to the clinical

38:49

horrify.

38:50

Okay. Thank you very much.

38:52

Thanks so much for sharing your lecture with us. If

38:55

anyone has any questions, please put them in that Q&A box and

38:58

we'll try to get through as many as we can before

39:01

hours up.

39:03

We've got a couple here that all toss

39:06

out to you Dr. Ali first in class

39:09

one Sunderland classification. Are there T2 changes

39:12

in the muscle or the nerve?

39:14

only or both

39:16

yeah, so Summerlin the type one as

39:19

I said, it's kind of like a nerve bruise, right? Like if someone punched you

39:22

in the face, but they didn't break anything. Right? So you'll recover you

39:25

still can have your modeling career ahead

39:28

of you if you get punched in the face with just the black eye, right? They didn't

39:31

hit your zygomatic Arch. It didn't fracture. You may still have your

39:34

beautiful teeth bones and everything. That's the way I think of Sunderland type one

39:37

injury. So so there aren't muscle changes.

39:40

So when you start to see any sort of muscle changes,

39:43

you should be concerned that it's it's above a class

39:46

one type of injury.

39:50

Any chance to assess cn4?

39:53

So we are not really

39:56

able to visualize a cn4 very well.

39:59

If an incredibly tiny nerve we can

40:02

see it intracranially and we can see it along the the course

40:05

of

40:06

At the the intracranial portion

40:09

along the tentorium, but we have difficulty visualizing it

40:12

in the orbit and it hasn't really been

40:15

a big push for us because a it tends

40:18

not to result in, you know, like a facial pain syndrome

40:21

that that we tend to

40:24

get these referrals for because it's a motor nerve and then

40:27

the injuries to cranial nerve for tend to

40:30

be intercranial along the tentorium from

40:33

that, you know Crossing on it from the tutorium. So so it

40:36

tends not to have pathology that's beyond the school-based. It

40:39

tends to be more of an intracranial type of pathology. So we

40:42

haven't really had requests for cranial in

40:45

there for and we do have difficulty visualizing it

40:48

consistently.

40:50

And we did actually I'll tell

40:53

you we did a cadaver.

40:55

And and if you have someone laying that

40:58

still for that amount of time and we did

41:01

a third cadaver head that you can see it, but but

41:04

it's more difficult and in true clinical

41:07

scenarios.

41:09

What recommendations can you give if we are trying to

41:12

achieve these results on a 1.5 Tesla?

41:16

And I have to be honest with you. I don't think it's it

41:19

it would work and I think that the scan times

41:22

would be too long and for the patients to

41:25

be able to tolerate it and to be able

41:28

to get the resolution that you need and

41:31

I think you'd have a lot of promotion artifact. So I would I

41:34

would just say that if you're going to do this type of Imaging you

41:37

really need a 3T to

41:40

be able to feel confident you're diagnosis,

41:43

you know, there's a lot of you know

41:46

artifacts that can you

41:49

make it very difficult to tell if like a nervous truly

41:52

injured or if it's motion. So you really need to have high quality

41:55

images to be able to perform this well.

41:58

This might be related to that last one. How can

42:01

we perform the reverse Fiesta sequence on a 1.5 Tesla

42:04

MRI. So you definitely you definitely

42:07

can the problem is that you're just not gonna be able to get the spatial

42:10

resolution to get you know that 0.5 millimeter isotropic

42:13

coverage to get the entirety of the

42:17

you know, basically the skull base and and they

42:20

have to extend it through the face as well for these nerves and

42:23

the time would be extremely long and

42:26

it's difficult for patients the whole

42:29

still and because we're Imaging things that are so tiny

42:32

and little bit

42:35

of motion can make it very difficult and you

42:38

know, it's not a easy sequence to

42:41

Simply, you know, pull out

42:44

of a box and and do I'm going to be honest with you like that's why

42:47

my my acknowledgments include our you

42:50

know, Mr. Physicist why we were scanning, you know severed heads.

42:53

There there is you do

42:56

have to have a certain level of quality assurance.

42:58

Do need a 3T and you do need the patient holding still

43:01

and you do need to be able to

43:04

do those multiplayer curve reformat?

43:08

I often do neck biopsy and fnc. What

43:11

is the percentage of injury to accessory nerve by

43:14

doing fnc or biopsy?

43:18

It's like so fine needle biopsy. So

43:21

so it comes not to be you know, really the

43:24

a if you're a radiologist a tends

43:27

on to be the radiologist who are doing a lot of the accessory nerve

43:30

damage and it's usually tends to because you

43:33

know, we're usually right in the limit. It usually tends to be

43:36

people who are doing it percutaneously by palpation and who

43:39

may not be quite as accurate, but certainly the

43:42

FNA needles the size of them are

43:45

not

43:46

usually associated with accessory nerve injury. It's

43:49

usually when you're coring those those and

43:52

and unfortunately, sometimes you do need the core, you know,

43:55

they you can't get a diagnosis just based on the

43:58

FNA sometimes

44:00

right next one. I understand you acquire a

44:03

T2 stir image and a black blood sequence

44:06

to create these images. Do you do a substraction of

44:09

these sequences in order to create the final product?

44:12

It's not a story. It's actually it's a T2 fat thought

44:15

with a with it with it with a back but and it

44:18

is all it's all one sequence. So um for so,

44:21

so that's the sequence that we do for the

44:24

brachial access and it's actually on Phillips. It's

44:27

called nerve you so it's a T2 with black bull

44:30

a tt5 with black blood. So it's not a subtraction image. It's

44:33

all part of one acquisition.

44:36

Okay. I know I'll avoid talking

44:39

about fins and and pulses and things

44:42

like that and but those never seem to help anybody.

44:45

But yeah, it's all one. It's all one package.

44:49

Um, great. I think this question says

44:52

can you add in small coils?

44:55

Does that make sense?

44:57

I don't know. I mean, can you can you

45:00

do it on like a 16 or an eight channel and head coil?

45:04

You can't and the time is going to

45:07

be a little bit longer and also the 32 Channel head coil. This

45:10

has better superficial and image quality.

45:13

So that's why we like to do the 32 head

45:16

Channel and coil, but

45:19

but you can do it and initially we when

45:23

we were trying to set this up we

45:26

were doing both. I thought the image quality was

45:29

better with 32, but but you

45:32

can do it with lesser and get pretty

45:35

good image quality.

45:38

Which machine do you use is

45:41

it Siemens 3T?

45:44

And now it these are

45:47

all these are all actually a Phillips. I'm ingenia and but

45:50

I'm I have to say that I think demons has

45:53

incredible image quality and I'm sure that the that you

45:56

can get, you know, certainly equivalent and

46:00

And his quality you think a demon system?

46:04

Awesome. Well, there's one more question. I'm curious

46:07

any advice for new new neuroradiology fellows

46:10

and training.

46:13

And read as much as you can and you

46:16

know, I I feel like like nothing

46:19

nothing makes you a better ideologist than just

46:22

seeing as much as possible. There is

46:25

no such thing as a wasted study, even

46:28

those negative studies that you're annoyed with

46:31

on call that the ER is sending you they are

46:34

teaching your brain. What's normal and

46:37

every time you go through them that's reinforcing your

46:40

brain. What's normal so that the abnormal stuff

46:43

will start to pop out to you. So there is

46:46

no better advice that I give to any radiologist New

46:49

Old, you know about to retire

46:52

the more you read the better you

46:55

are so it's all about I think is much

46:58

volume as you can.

47:00

Also, thanks so much for answering all those questions and thank you

47:03

for your lecture today, and for everyone else for being here and

47:06

asking those questions. You can access the recording of

47:09

today's conference and all our previous new conferences by creating a

47:12

free MRI online account, and you can join us

47:15

next week, Thursday, April 13th at 12 pm featuring

47:18

Dr. Francis ding for a case review live on head

47:21

CT perfusion cases. You can register for this free

47:24

lecture MRI online.com follow us on social media for future

47:27

new conferences. Thanks again, and have a

47:30

great day.