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radiology subspecialties.

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Today we are honored to welcome Dr.

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Mohe Agarwal for a lectured entitled role

0:39

of imaging in s nasal masses.

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Dr. Agarwal is an associate professor of neuroradiology

0:46

and program director

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of the Neuroradiology Fellowship Program

0:49

at the Medical College of Wisconsin

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and Milwaukee, Wisconsin.

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He is a passionate educator who has been repeatedly honored

0:56

for his teaching by fellows, residents,

0:59

and medical students at MCW

1:01

and recently received the A three CR two outstanding teacher

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award from the A UR.

1:07

He also founded the Cortex Club

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and online community that enhances neuroradiology education

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through weekly quizzes, video lectures,

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and sessions by world renowned educators.

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We're thrilled. He's here today to share in his expertise.

1:20

At the end of the lecture, please join him in a q

1:22

and a session where he will answer questions you may

1:25

have on today's topic.

1:26

Please remember to use that q

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

1:30

as many as we can before our time is up.

1:32

And with that, we are ready to begin today's lecture. Dr.

1:35

Agarwal, please take it from here.

1:39

All right, thank you very much for that introduction

1:41

and thank you to, uh, MRI online

1:44

and ality, uh, for this invitation.

1:47

So, uh, in the next, uh, you know, 45, 40 45 minutes

1:51

or so, we are gonna be talking about the role

1:52

of imaging in Sano nasal masses.

1:54

So, you know, San Nasal disease is a very, uh,

1:58

commonplace in neurology practice on a daily basis.

2:01

When we read, um, you know, head cts that had MRIs,

2:04

we routinely look at the perinasal sinuses.

2:07

Uh, and every once in a while, you know, uh,

2:09

quite commonly we encounter inflammatory disease.

2:11

But then, uh, you know, every once in a while, we, uh,

2:15

also encounter other diseases in the paranasal sinuses,

2:17

and then of course, we, uh, evaluate them, uh,

2:20

with a dedicated, uh, exam of the perinasal sinuses.

2:24

So, uh, in this lecture, I'm gonna, uh, you know, uh,

2:27

talk about how to approach these cases with San nasal, uh,

2:31

lesions, and then talk about what the role of imaging

2:35

and imager is, uh, in the s nasal, uh, lesions.

2:40

So, uh, you know, that is the objective for today.

2:42

So we'll discuss the strategy to approach, uh,

2:45

approach a case with a s nasal lesion

2:47

and then discuss the role, you know,

2:49

which is more important, discuss the role

2:51

of imaging and the imager.

2:55

Right? So, uh, you know,

2:57

before I get into, into the meat of my talk, I just wanted

2:59

to show this case to you, uh, and,

3:01

and let you come up with, uh, you know, sort of a diagnosis

3:04

of what this could be, and I'll give you a few seconds here.

3:13

Alright, so we have a right, uh, maxillary sinus mass,

3:16

and as you can see, you know, there,

3:17

there are some bony changes.

3:18

You know, it looks very, uh, heterogeneous,

3:20

that is heterogeneous post contrast enhancement.

3:23

And I can tell you that this, this, uh, lesion turned out

3:26

to be a maxillary sin ameloblast.

3:29

I can tell you very honestly,

3:30

that this diagnosis was nowhere in the first five diagnoses,

3:34

uh, that I was thinking about when I was reading this case.

3:37

And here's, uh, another case of a ano nasal lesion.

3:41

Here we have, uh, a lesion in the right nasal cavity,

3:45

ethmoid sinuses, again, with a lot of boning changes, um,

3:48

a heterogeneous post contrast enhancement

3:50

and also some lymphadenopathy.

3:52

So I'll give you another few seconds to, to, uh, think about

3:56

what this could be.

4:02

Alright, and this turned out

4:05

to be a sanal undifferentiated carcinoma.

4:08

So the point that I'm trying to make here is that

4:11

of all these lesions that have been classified

4:14

or described in the WHO classification of, you know, many,

4:17

uh, various kind of histology, you know,

4:19

varied histological types, it is very difficult to come up

4:23

with a histological diagnosis in these cases

4:26

because a lot of sanal lesions, um, you know,

4:29

especially the malignant ones look very

4:32

similar to each other.

4:33

So it's very difficult to come up

4:35

with a histological diagnosis as imagers, you know,

4:38

is always our urge

4:40

to make a histological diagnosis when we are looking at

4:43

any kind of pathology.

4:44

But when you are looking at sanon nasal lesions, it is, uh,

4:48

you know, sort of, I will request you

4:50

or urge you to check that, um, uh, sort of inclination

4:53

to make a histological diagnosis

4:55

because of what we just saw.

4:56

You know, these sanon asal lesions,

4:58

especially the malignant ones are so similar to each other,

5:01

that our role as imager is not to come up

5:05

with a histological diagnosis.

5:07

Our role in the, uh, management

5:10

of sanas lesions is number one, to differentiate whether

5:13

or not we are lesion, uh, dealing with a malignant lesion

5:16

or a benign lesion.

5:17

So that's something, uh, you know, that is a distinction

5:20

that we are sort of supposed to make, whether we are dealing

5:23

with a brine or magnetic lesion.

5:24

And when we know that we are dealing

5:26

with a malignant lesion, then the most important role

5:30

of a radiologist or an imager is to do tumor mapping.

5:33

You know, what is the size of the lesion?

5:34

What is the extent of the lesion,

5:36

what different structures it is involving at?

5:39

That is our main role when we are looking at malignant san

5:43

na lesions or even benign san na lesions.

5:46

And every once in a while,

5:47

when you're looking at these lesions, you know,

5:48

there might be some, so to speak, light moments

5:51

where you have some characteristic features, uh,

5:54

of these lesions where you may suggest a diagnosis.

5:56

But keeping in mind that a logical diagnosis is not the

6:00

primary role of a radiologist when we are looking at

6:03

san nasal lesions.

6:06

So with this in mind, uh, you know, uh, the vast majority

6:10

of san nasal lesions that you will see

6:12

or you'll encounter are going

6:16

to be benign inflammatory lesions.

6:19

And these are at most times, um, you know, um, sort of, um,

6:23

easy to be differentiated from malignant lesions in that,

6:27

uh, most benign lesions are, uh, let me open this up.

6:32

Um, alright.

6:34

Most benign lesions are well-defined,

6:36

whereas malignant lesions have this infiltrative appearance,

6:39

you know, they will invade these surrounding soft tissues

6:41

and will have that infiltrative margin, which is more common

6:44

with malignant lesions, whereas benign lesions tend

6:47

to be more, well-defined adjacent bones.

6:50

So benign lesions tend to call this, uh,

6:52

cause this bony remodeling,

6:53

whereas malignant lesions cause bone erosion.

6:56

So when you see erosive changes in the bone,

6:59

you're more likely to think about malignant lesions,

7:01

whereas when you see bony remodeling

7:04

or expansion of the bone than a benign lesion is, uh,

7:08

is more, more likely then the surrounding tissue planes.

7:11

So the benign lesions tend to cause displacement

7:14

of the tissue plane, so the surrounding soft tissues would

7:16

be displaced, whereas in malignant lesions,

7:19

there would be invasion of the surrounding soft tissue.

7:21

There will be, uh, infiltration

7:23

of the surrounding soft tissue.

7:24

As you can see here, you know, this is a malignant lesion,

7:26

and you can see that there is infiltration

7:29

of the surrounding soft tissue,

7:30

whereas this is a benign lesion,

7:32

and you can see that the surrounding soft tissue is

7:34

displaced and not directly invaded.

7:37

Then T two signal.

7:39

So most benign inflammatory lesions have, uh,

7:42

a high water content, and

7:43

therefore they have a high T two signal

7:46

because of the, um, a high water content.

7:48

Whereas most more malignant lesions

7:50

or most malignant lesions have hyper cellularity.

7:53

They have increased cellularity and a low water content, and

7:57

therefore they have a low T two signal.

8:00

Uh, by same principle, the diffusivity

8:02

of benign lesions is increased

8:04

because of high water content, and

8:06

because, uh, most malignant lesions are hypercellular,

8:09

they have a low water content,

8:11

they have this high nuclear cytoplasmic ratio,

8:14

the diffusivity in most malignant lesions is, uh, reduced.

8:18

Then, uh, benign lesions usually have a

8:21

homogenous enhancement.

8:22

Again, as you can see here,

8:23

there is a more homogenous enhancement in this, um,

8:26

schwannoma of the left, uh, maxillary sinus.

8:29

Whereas, uh, malignant lesions have a, um,

8:31

heterogeneous post contrast enhancement, as you can see here

8:35

and here, and here are, uh, more examples of what, um,

8:39

of the different features

8:40

of these benign and malignant lesions.

8:41

So benign lesions tend to cause this bony remodeling.

8:45

As you can see, there is expansion of the bone,

8:47

there is remodeling of the bone, but there is no erosion.

8:49

Whereas in, in malignant lesions, you can see

8:52

that there is frank bony erosion of these margins.

8:55

Again, the soft tissue planes are displaced in a malignant

8:59

lesions, uh, in a, in a benign lesion,

9:01

whereas in a malignant lesion,

9:02

the soft tissue planes are infiltrated.

9:05

And here is an example of, uh, the T two signal and benign

9:08

and malignant lesions.

9:10

In benign lesions, you will see this high T two signal

9:12

because of a high water content.

9:14

This is a, uh, sanon nasal polyp,

9:16

whereas this is a malignant lesion and adeno cystic cancer,

9:19

and you can see that there is a low T two signal

9:22

because of the hyper cellularity and the low water content.

9:26

Uh, by same principle, you know,

9:27

there is reduced diffusivity in malignant lesions.

9:31

This is a san nasal lymphoma,

9:33

and you can see that there is reduced diffusion here.

9:35

Whereas here, this is, uh, a, uh, uh, uh, polypoid lesion,

9:40

and this shows increased diffusivity

9:42

because of the, uh, high water content.

9:45

Then, uh, enhancement.

9:46

This is a schwannoma that shows homogenous enhancement,

9:49

whereas this is a, uh, squamous cell carcin one, you can see

9:52

that that is heterogeneous post contrast enhancement in

9:55

malignant lesions.

9:58

Then once we know that we are dealing

10:00

with a malignant lesion, again, you know, I would say again

10:03

that the role of the imager isn't tumor mapping.

10:06

So once you see the malignant, uh, malignant lesion,

10:08

the next step should not be

10:09

to jump at histological diagnosis, but to map the tumor.

10:14

And in mapping the tumor, there are certain things

10:16

that we, uh, must describe.

10:18

You know, what is the size of the lesion?

10:20

And when we are measuring the size of the lesion,

10:22

it is important to differentiate enhancing tumor from

10:26

and retain secretions, which are very common

10:29

with malignant lesions because of, uh, narrowing

10:32

or occlusion of the, uh, sinus drainage pathways.

10:35

Then multis sinus involvement is important

10:37

because it st uh, it changes the staging of the tumor.

10:41

So whether one sinus involved

10:42

or it is, uh, invading other sinuses in the vicinity.

10:46

So that is important to be described

10:48

because if there is multis sinus involvement,

10:50

it increases the de staging of the tumor.

10:52

Then of course, we have to describe or, uh, or see whether

10:56

or not there is involvement of the sinus drainage pathways,

10:58

because that's going to occlude, uh, these sinuses

11:02

and cause retained secretions.

11:04

Then adjacent soft tissue involvement, you know,

11:06

very important to be described

11:07

because it significantly changes the t stating of the tumor,

11:10

whether or not there is, you know,

11:12

pre maxillary fat pattern involvement, whether

11:14

or not there is skin involvement.

11:16

You know, which aspect of the maxillary sinuses involved,

11:18

whether it's the anterior aspect or the posterior aspect.

11:21

All these, uh, uh, changes

11:24

or the extent of the tumor involvement adjacent soft tissue

11:27

involvement is important to be described,

11:29

and that is the role of the amateur to tell the surgeon

11:32

what surrounding soft, uh,

11:33

soft tissue structures are, uh, involved.

11:36

Then orbital involvement, you know, frequent with ethmoid,

11:40

uh, uh, cancers or, uh, frontal sinus cancers.

11:44

And, uh, when there is orbital involvement, again,

11:46

it changes the d staging of the tumor.

11:49

So important to, um, you know,

11:51

keep it in your search pattern

11:52

and important to describe whether

11:54

or not there is overal involvement.

11:56

Then tumors in the ethmoid sinuses

11:58

and superior nasal cavity frequently, uh,

12:01

have intracranial extension.

12:03

So that is also very, very important to look at,

12:05

to describe, you know, whether there is erosion

12:08

of the skull base, whether

12:10

or not there is invasion of the dura, whether

12:12

or not there is nodular dural enhancement

12:14

or involvement ofi, uh, adjacent brain parenchyma.

12:18

Then perineal tumor spread, again, very important changes.

12:21

The staging of the tumor.

12:23

Uh, it is important in treatment planning as well.

12:26

So perineal tumor spread, so should always be a part

12:29

of your search pattern.

12:30

So look at the different, um, nerves

12:32

that are in the vicinity of, uh, the tumor, uh,

12:35

and make sure that there is no perineural tumor spread.

12:38

Lymphadenopathy, you know, it's not very common

12:41

with sanon nasal lesions,

12:42

but it, it can happen, uh, especially with, uh, you know,

12:45

higher grade tumors like san nasal undifferentiated cancers,

12:49

not midline cancers or anesthesia neuroblastomas.

12:52

These are, you know, some of course lymphomas.

12:55

These are some of the, uh, cancers where lymphadenopathy,

12:59

uh, may, may occur.

13:01

So of course, you know, keep an eye out for any, uh,

13:04

level one and two lymphadenopathy

13:06

or any retropharyngeal lymphadenopathy.

13:08

Then distant metastasis, again, not very common

13:10

with sanon nasal lesions,

13:11

but with, uh, higher grade tumors like, um,

13:14

undifferentiated cancers

13:15

or not midline cancers, you can also have, uh,

13:19

distant metastasis.

13:20

So this should be sort of part, part of your search pattern,

13:23

and this is our primary role when we are dealing

13:26

with sanon nasal malignancies.

13:30

Then if, if tumor mapping is our primary role,

13:36

you know, what are the different things that,

13:38

that we have to describe?

13:39

So, number one is to describe the size of the tumor,

13:43

and when we are describing the size of the tumor,

13:45

it is very important to differentiate the enhancing tumor

13:49

from retained secretions.

13:50

For example, in this case, you know, just

13:52

by looking at the ct, it is very, uh, difficult

13:55

to differentiate tumor from retained secretions.

13:57

But as we, uh, look at the mr, we can see that there is,

14:01

you know, a little bit of, uh, differentiation between, uh,

14:04

this portion, um, and this part of the, of the lesion.

14:08

And as we look at, you know, more images, post contrast,

14:12

MR images are very, very useful in differentiating retain

14:16

secretions from, uh, enhancing tumor.

14:18

So on this post contrast, mr, we can very well see

14:21

that the enhancing tumor

14:23

or the tumor, uh, is actually only from here to here,

14:26

and this part of the, um,

14:28

of the whole lesion is just retained secretion.

14:30

So very important to look at post contrast imaging,

14:33

post contrast, MR images to, uh, to know the exact, uh,

14:37

exact size of the lesion,

14:39

and very important to differentiate it from,

14:41

uh, retain secretions.

14:42

Always important to keep that in mind, that accurate, um,

14:46

measurement of the tumor size is important.

14:50

Then, um, a multiple site

14:53

or sub site involvement is also very important

14:55

because, uh, as there is involvement of more sinuses,

14:58

more subsites, it increases the t staging of the tumor.

15:02

It is very important in, uh, nasal cavity cancers

15:05

where involvement of more than one sub site

15:08

increases the T stage of the tumor.

15:10

So, for example, this tumor in the nasal cavity, uh, where,

15:14

um, you know, there is, uh, there is no involvement

15:16

of the nasal septum, has a lower T stage compared

15:19

to this particular lesion that has involved the nasal septum

15:22

and has extended, uh, to the other side.

15:25

And there is also involvement of the, um, uh,

15:27

of the orbital structure.

15:28

So, uh, involvement of the nasal septum involvement

15:32

of more than subside increases the T stage of the tumor.

15:35

So very important to describe whether the lesion is, uh,

15:39

involving one site or multiple sites or subsides.

15:45

Then, uh, again, you know, uh, uh, this tumor,

15:48

this maxillary sinus tumor

15:49

that has involved the sphenoid sinus has involved the

15:52

posterior, uh, masticator space has a much higher

15:56

T stage compared to tumors that are confined

15:59

to the maxi three sinus.

16:00

So again, this, this tumor is going

16:02

to have a much higher T stage compared to, uh, a lesion

16:05

that is only involving the, uh, maxillary sinus,

16:10

then involvement of adjacent soft tissues.

16:12

So, again, very important you know,

16:14

which soft tissues are involved.

16:16

So for example, in this maxillary sinus cancer,

16:18

the involvement of anterior, uh, uh, maxillary sinus wall

16:22

and involvement of an anterior soft tissues has a lower T

16:25

stage T two compared to involvement

16:28

of the posterior maxillary sinus or posterior soft tissue.

16:31

And this is a higher T stage

16:33

or T three, when there is involvement of the posterior part

16:36

of the maxillary sinus or posterior position, soft tissues.

16:39

Then involvement of the anterior subcutaneous soft tissue

16:42

has a lower T stage T three compared to involvement

16:46

of the entire thickness of the soft tissue

16:48

and involvement of the overlying skin.

16:50

So, again, you know, when you're describing

16:52

or mapping out the tumor, just saying

16:55

that the pre max three soft tissues are

16:57

involved is not sufficient.

16:58

You know, you have to describe what extent

17:00

of the anti xray soft tissues is involved,

17:03

whether it is just the subcutaneous tissue

17:06

or that is involvement of the entire thickness

17:08

and involvement of the overlying skin as we see here,

17:11

because this has a much higher T stage T four compared

17:15

to this, which is, uh, T three, then orbital involvement,

17:20

very, very important, uh, you know, increases the t staging

17:23

of the tumor, and again, in, in involvement of orbital uh,

17:27

structures, involvement of the orbital wall, involvement

17:31

of the orbital contents

17:32

and which part of the orbital contents are involved,

17:35

is also a determinant of the t staging of the tumor.

17:38

So, for example, involvement

17:40

of just the orbital wall is T three, whereas involvement

17:44

of the anterior orbital soft tissues is T four.

17:48

But if there is involvement

17:49

of the posterior orbital soft tissues

17:51

and the orbital apex, this take takes the tumor staging

17:54

to its highest tumor stage, which is T four B.

17:57

So when you're, uh, describing orbital involvement,

18:01

you know, it's important to say whether it's just the

18:03

orbital wall that is involved,

18:05

or whether it's orbital soft tissues that are involved,

18:08

and if the orbital soft tissues are involved, which part

18:10

of the orbital soft tissues are involved,

18:12

whether it is the anterior orbital soft tissues,

18:15

the posterior orbital soft tissues, or the orbital apex,

18:18

because each, uh, uh, kind of involvement has a different

18:23

T stage then involvement of intracranial structures,

18:28

you know, very, very important.

18:30

Again, you know, the extent of intraoral involvement will,

18:34

uh, change the D stage.

18:36

So involvement of the cribriform plate is T three,

18:39

whereas involvement of the dura,

18:41

when you see nodular enhancement of the dura

18:44

and where there is involvement of the brain parenchyma

18:46

with enhancement of the brain parenchyma

18:48

and abnormal signal, that is a higher T stage or T four.

18:52

So just the erosion, you know, when you're describing, uh,

18:55

a superior nasal cavity tumor, just saying

18:57

that there is intracranial extension is not enough.

19:00

You know, what is the extent

19:01

of the intracranial, um, extension?

19:03

Is that just erosion of the, uh, bony skull base?

19:06

Is there involvement of the dura?

19:08

Do you see nodular enhancement or do you see frank invasion

19:13

or involvement of the brain parenchyma?

19:15

All these things are important to be described

19:18

and do determine the t staging of the tumor.

19:23

Then perineal tumor spread, you know, as we, um,

19:26

already talked about very, very important changes,

19:28

the t stage and also is important in, um, in management,

19:33

uh, of these lesions

19:35

because, uh, the radiation fields going

19:37

to change if there is, uh, perineal tumor spread.

19:40

And, you know, the branches

19:42

of fifth nerve are everywhere in the face.

19:45

And when we are, uh, describing perineal tumor spread,

19:48

you know, these, these little fat pads that are at the entry

19:51

and exit sites of, uh, these branches

19:54

of the trigeminal nerve, they're important to be looked at.

19:57

You know, I would, uh, encourage you to make, uh,

20:00

perineal tumor spread evaluation as part

20:03

of your search pattern when you're looking at head neck

20:05

malignancies, especially san nasal malignancies

20:07

because it's, it's important, uh, uh, in management.

20:11

And frequently you will see that there is involvement

20:14

of the, uh, cranial nerves that are in the, uh, the branches

20:17

of the fifth nerve that are in the, in the phase.

20:20

So prem max three fat pad for V two, uh, tego palatine fossa

20:24

for, um, you know, of course V two

20:25

and also part of the video nerve.

20:27

And then for and rotund where the V two lives, uh,

20:30

the inferior alveolar nerve that can be involved,

20:32

which is branch of the V three.

20:33

And of course, you can directly see the for

20:36

and val, where the V three uh, exits the, the skull base.

20:39

And these are examples

20:40

of perineal tumor spread in san nasal cancers.

20:43

Here you can see that there is soft tissue in the pre

20:45

maxillary, um, area,

20:47

and there is involvement of the infraorbital nerve.

20:50

Here you can see that there is a posteriorly, uh,

20:53

posteriorly placed max three sinus cancer,

20:55

and there is infiltration of the Rigo palatine fossa,

20:58

which raises concern for perineal tumor spread.

21:00

Here you can see that there is, uh,

21:02

asymmetric enhancement within the for

21:04

and rotund, which means

21:05

that there is peral tumor spread along the B two nerve.

21:09

Here you can see that there is, uh, infiltration

21:12

of the inferior alveolar nerve

21:14

or the, uh, uh, the frame, uh, the, uh, mandibular forman.

21:18

So there is peral tumor spread

21:19

along the inferior ular nerve.

21:21

And here you can see

21:22

that there is asymmetric enhancement along the V three in

21:26

the F valley, which again raises a concern for

21:29

peral tumor spread along V three

21:33

then lymphadenopathy, you know, not very common

21:35

with san nasal cancers,

21:40

but here are some examples of lymphadenopathy in

21:43

san nasal malignancies.

21:44

So this was a san nasal melanoma,

21:46

and we had, you know, level, uh, one B lymphadenopathy here,

21:50

very bulky lymph nodes.

21:51

This was a s nasal undifferentiated cancer

21:54

with bilateral level two, um,

21:56

lymphadenopathy more on the right,

21:58

and this was an anesthesia neuroblastoma where you can see,

22:00

uh, level two lymph node involvement.

22:02

So, uh, not very common,

22:04

but always, you know, keep an eye out

22:07

for potential lymphadenopathy in, uh, san nasal cancers.

22:12

Then in terms of imaging modalities, you know, um, CT

22:16

and MR are definitely complimentary when we are evaluating,

22:19

uh, san nasal cancers.

22:21

CT is very useful in evaluation of cortical erosion, erosion

22:25

of the sinus septa, when we are evaluated

22:27

for multis sinus involvement.

22:29

Also, uh, involvement

22:31

of other bony structures like the bony palate,

22:33

the orbital apex, the orbital walls,

22:35

and the bony skull base, all of which, by the way,

22:37

are determinants of the staging of the tumor, uh,

22:41

is done better by ct, whereas bone marrow invasion,

22:44

you know, if there is involvement of the bone marrow, it's,

22:46

uh, better seen on MRI, uh, differentiate, uh,

22:49

of tumor from secretions.

22:51

As we saw in our case, you know, enhancing tumor is, uh,

22:54

differentiated well on post contrast MRI sequences.

22:58

Uh, so differentiation of tumor

23:00

or accurate measurement of the tumor, uh, is better on MRI

23:05

peroneal tumor spread.

23:06

Of course, you know, subtlely peroneal tumor spread may be

23:08

missed on ct, but can be seen very well on MRI,

23:12

and of course, involvement of the dura involvement

23:14

of the brain is much better seen on MRI compared to, uh, ct.

23:20

So, you know, once we know that we are, um, dealing with,

23:25

uh, malignant san nasal lesions, uh, there are certain, uh,

23:29

things that, you know, we have to keep in mind, uh,

23:32

squamous cell cancer with the most common malignant tumor

23:35

of the San nasal cavity.

23:36

So, um, you know, it's by far the most common tumor.

23:40

So important to keep in mind.

23:41

The squamous cell cancer is the most common,

23:44

and it likes the maxillary sinus,

23:46

so most common in the maxillary sinus,

23:48

but adenocarcinomas are more common in the,

23:50

uh, ethmoid cavities.

23:51

Again, the most common tumor even in the ethmoid sinuses is

23:56

going to be a squamous cell cancer.

23:57

But adenocarcinomas, if you,

23:59

if you look at all adenocarcinomas that are, uh,

24:02

probably more adenocarcinomas in the, uh, ethmoid sinuses,

24:05

then melanomas are more common in the nasal cavity

24:08

and asthe neuroblastomas

24:10

because they arise from the olfactory epithelium,

24:12

they're more common in the, uh, upper nasal cavity.

24:15

So just, you know, just, uh, a few important, uh,

24:18

considerations when we are looking at these,

24:20

uh, ano nasal masses.

24:23

And, and this brings me to, uh, you know, our next slide.

24:26

So, uh, you know, initially when I said, you know, our,

24:29

our role as imagers, uh, is to do tumor mapping.

24:32

You know, first of all, differentiate whether, uh,

24:34

we are dealing with a benign lesion or a malignant lesion,

24:37

and if we, and if we do think we are dealing

24:39

with malignant lesions, our role is to do tumor mapping.

24:43

But every once in a while, you know,

24:44

you might see some lesions

24:46

that have certain characteristic features,

24:48

and you might have this, you know, sort

24:50

of light bulb moment.

24:51

And this is that slide where I'm showing you some

24:54

of the characteristic features of, uh,

24:56

of some of these lesions.

24:57

So if you see a lesion that has this convoluted

25:00

or cerebral foam appearance, especially if it is associated

25:04

with the bony spur on one of the max three sinus walls,

25:06

you think of an inverted papilloma.

25:09

If you see a lesion that has, you know,

25:11

intrinsic T one hyperintensity, you know me melanin is,

25:15

is paramagnetic

25:16

and is bright on, uh, pre contrast T one weighted images.

25:20

So if you see pre contrast T one hyperintensity in a sanon

25:24

nasal lesion, think of a metic melanoma, again, important

25:27

to know that it's only the metic melanomas

25:30

that are T one hyperintense non-melanoma melanomas, again,

25:33

would not be T one hyperintense

25:34

and would look like any of sanon AAL lesion.

25:37

Then lymphomas, because of their hyper cellularity,

25:40

because of high nucle cytoplasmic ratio, uh,

25:43

reduce diffusion much more than other San AAL lesions.

25:46

So if you see a, uh, T two dark lesion, again,

25:49

lymphomas are also T two dark

25:50

because of the hyper cellularity.

25:52

So if you see a homogenous T two dark lesion that has, uh,

25:56

reduced diffusivity, you know,

25:58

it's more likely to be a lymphoma.

26:00

Then, uh, when you see a lesion, uh,

26:03

a mass in the upper nasal cavity with intracranial extension

26:06

and cyst formation at the tumor brain interface, you know,

26:09

it, you can think about an anesthesia neuroblastoma also,

26:13

um, although, you know, formation

26:14

of peritumoral cyst is not unique

26:16

to anesthesia neuroblastomas

26:18

and can happen with, uh, other, uh, lesions as well.

26:22

Then perineal tumor spread, you know, by far,

26:25

because squamous cell cancers are more common, the more,

26:29

most commonly if you see perineal tumor spread, it is again,

26:32

would be more likely to be seen with squamous cell cancers

26:35

because they're far more common.

26:37

But adenoid cystic ansys have a propensity

26:40

for ery perineal tumor spread.

26:41

So, you know, something

26:43

to keep in mind then if you see hypervascular tumor in an

26:47

adolescent, think of a J

26:49

and a, uh, if, uh, you know,

26:51

sarcomas are not very common in the San nasal region,

26:54

but of course, if you see a lesion

26:56

that has this typical oxen ring type of calcification, think

26:59

of a chondro sarcoma.

27:01

Again, they're not very common,

27:02

and if you see an osteoid matrix, then think

27:05

of osteosarcoma.

27:09

Alright? So, uh, you know, these are,

27:14

these are the basic pri principles that I want you all

27:17

to remember, you know, um, differentiation

27:19

of blind from malignant, um, mapping of the tumor.

27:23

And then, you know, with these princip, um, uh,

27:25

with these principles, you know, if,

27:27

if you have a characteristic feature, then, uh,

27:29

maybe suggest a histological type,

27:31

but keeping in mind that that is not our, uh, primary role.

27:34

So with these principles,

27:35

let's, let's look at some of the cases.

27:37

So here we have a right max re sinus lesion, um,

27:41

and we can see that this is very homogenous on ct.

27:44

There is maybe some bony remodeling, you know, right here,

27:47

it, it looks like it is displacing, uh, it is widening the,

27:50

uh, max three sinus in lum.

27:52

Maybe there is some remodeling of the middle

27:53

and the inferior terminates on mr.

27:55

However, this is so homogenously T two hyperintense,

27:58

so a very high water content on post contrast imaging.

28:02

There is hardly any enhancement.

28:04

The enhancement that we see is only

28:06

of the surrounding mucosa on these axial pro images.

28:10

And so just by these imaging features, we know

28:12

that we are dealing with a benign sanal lesion.

28:15

And you all know what I'm talking about.

28:17

This is just an a**l polyp in the right maxillary sinus

28:20

that has extended into the, uh, nasal cavity.

28:24

Then another lesion here.

28:26

So, um, you know, on, on, uh, this axial, um, store image,

28:30

it, it's a little, little bit heterogeneous, uh,

28:32

also showing, uh, heterogeneity on this axial, uh,

28:35

on this coronal store image.

28:37

Uh, on ct,

28:38

however, we see that, you know, there is,

28:40

there is no bony destruction

28:41

that is actually bony hyperos ptosis

28:44

on post contrast enhancement.

28:46

There is a lot of enhancement, very avidly enhancing,

28:49

and if we look closely again on the ct, we see

28:51

that there is this bony spur on the posterior lateral wall

28:54

of the maxillary sinus.

28:56

And if we go back to look at this, this lesion, we do see

28:59

that this has some of a somewhat of a convoluted

29:02

or a cerebral farm appearance.

29:04

And this brings us to one of our light bulb moments,

29:07

you know, with the bony spur, with the convoluted

29:10

and cerebral farm appearance.

29:11

You probably know, uh, what I'm talking about.

29:14

This, this lesion is an inverted papilloma.

29:16

So when you see this kind of lesion that causes, you know,

29:19

bony remodeling instead

29:20

of bony destruction has a cerebral form

29:22

or convoluted appearance,

29:24

and you see this bony spur, you know, you, you know

29:27

that you're dealing with it, uh, inverted pap

29:32

and, uh, another lesion in the maxillary sinus.

29:36

Um, as soon as we look at the ct, uh, we see a lot

29:39

of bony destruction.

29:40

We see that there is involvement of the pre

29:42

and posterior, um, uh, soft tissue.

29:45

So just by looking at the ct, we know that we are dealing

29:47

with a malignant lesion.

29:50

What is, what is this kind of lesion?

29:51

Is this a squamous cell cancer? Is this adenoid cystic?

29:54

We are not interested in that.

29:55

Remember, when you see a malignant lesion,

29:57

your tendency should not be to jump

29:59

to a histological diagnosis, but to do tumor mapping.

30:03

So we don't care about what, uh,

30:05

histological type this tumor is.

30:06

We care about the fact

30:08

that this lesion is eroding the posterior aspect

30:12

of the maxillary sinus that has a higher T stage compared

30:14

to involvement of the anterior, um, anterior maxi sinus.

30:18

Then there is involvement of the, uh, masticator space.

30:21

There is infiltration of the teco palatine fossa.

30:24

There is erosion of the teco palatine fossa.

30:26

There is, um, a, uh,

30:29

a pre maxillary soft tissue involvement.

30:31

So, you know, we, we are again, um, already thinking about

30:34

perineal tumor spread that may be, uh,

30:36

potentially be along the infraorbital nerve.

30:39

We look at this, uh, axial stir.

30:41

Again, we see a destructive lesion.

30:43

There is a lot, lot of involvement

30:45

of the anterior pre maxillary soft tissues involvement

30:48

of the, uh, uh, masticator space.

30:50

There is widening of the CCO palatine fossa.

30:53

Again, there is an enhancement here, anteriorly posteriorly.

30:58

Again, we can see that there is enhancement

31:00

of the TCO vaccine fossa.

31:01

That is something that we would describe on these images.

31:04

We can see that there is erosion of the bony palate,

31:07

you know, very important to be described

31:09

because this would potentially change the management.

31:11

There is extension into the nasal cavity.

31:14

On this axial post contrast image, there is involvement

31:17

of the inferior orbit that is thickening

31:19

of the inferior rectus muscle.

31:21

So there is involvement

31:22

of the anterior orbital structures important to be described

31:25

because it would change management.

31:27

And on these coronal images, we can see

31:28

that there is asymmetric enhancement of the frame

31:30

and rotund, and there is asymetic enhancement

31:33

within the for val.

31:34

So there is very neuro tumor spread along the B two

31:37

and the B three nerve.

31:38

So this is, these are all the, um, uh, points

31:42

that are important to be described when we see a malignant

31:46

lesion in the sanon AAL region.

31:47

Of course, this turned out to be a squamous cell cancer,

31:50

but that is not our primary goal to say

31:52

what the historical type of the tumor is,

31:54

but to describe the extent of the tumor.

31:58

Then another lesion in the, um, in the San Nasal region, uh,

32:03

there is erosion of the bony septa, uh, which tells us

32:06

that this is probably a malignant lesion.

32:08

We look at the, uh, we look at the post contrast images.

32:12

Again, you know, there is heterogeneous enhancement and,

32:15

and these images do, uh, help us differentiate the,

32:20

the size, so, uh, the size of the lesion.

32:22

So when we are describing this lesion,

32:23

we will measure it from here to here

32:25

and now the entire thing.

32:26

So that is important to be, um, to be described

32:30

and differentiated to differentiate the enhancing lesion

32:32

from the, uh, non enhancing pertain secretions.

32:35

When we, uh, describe this lesion, we are going to say

32:38

that there is, you know, no involvement of the orbit.

32:41

We don't see any intracranial extension.

32:43

Uh, and then, so these, these are the things

32:45

that we are important to be described

32:47

when we are describing the lesion.

32:48

We will accurately measure the tumor size.

32:51

We'll differentiate it from retain secretions,

32:53

and we will say that there is an, um, erosion

32:55

of the bon septa without involvement of the orbit

32:59

or the endocrine index, um, uh, structures.

33:01

And this turned out to be an adenocarcinoma.

33:03

Uh, but again, you know,

33:05

squamous cell carcinoma could look exactly the same.

33:10

Then another lesion, uh, uh,

33:11

this time in the posterior nasal cavity, uh,

33:14

there is erosion of the posterior wall

33:16

of the maxillary sinus.

33:18

And if you compare this ter ine fossa from the other side,

33:21

you can see that there is infiltration

33:23

of soft tissue here in the ter ine fossa.

33:26

Then on these coronal images, again, you can see

33:28

that there is soft tissue within the ter ine fossa compared

33:31

to the normal side.

33:32

So again, you know, the, uh, possibility

33:35

for perineal tumor spread is again, increased.

33:38

On this pre contrast T one weighted image,

33:40

we see this evil gray in the posterior

33:43

maxillary soft tissues.

33:45

Here again, you can see a low T two signal.

33:47

There is a lot of enhancement,

33:48

and you can see asymmetric enhancement within the TCO patine

33:52

fossa, and there is asymmetric enhancement along the dorum.

33:56

So there is early peroneal tumor spread in this posterior,

34:00

um, uh, nasal cap lesion in this turn out

34:02

to be in adenoid cystic cancer.

34:04

Again, you know, you, it's important

34:06

to describe the peroneal tumor spread to describe the extent

34:09

of the tumor and not, not really, uh, say that, you know,

34:12

this is an adenoid cystic.

34:16

This is, um, again,

34:18

another lesion in the superior nasal cavity.

34:21

Uh, and this one is, you know, a, a pretty big tumor.

34:24

We can see that there is involvement of the orbit.

34:26

There is involvement of the orbital structures.

34:28

There is erosion of the cribriform plate.

34:30

Of course, there is extension into the

34:32

intracranial compartment.

34:34

Here again, you can see orbital involvement,

34:36

you can see intracranial involvement,

34:38

and again, this probably has one of our light bulb features.

34:41

We can see that there is cyst formation at the tumor brain

34:45

interface here on this coronal image, on this s images.

34:49

And, uh, also on this stir axial image, you can see

34:53

that there is cyst formation of the tumor brain enter phase.

34:56

It is in the superior nasal cavity, so you might suggest

34:59

that this might be a,

35:00

and this might be olfactory neuroblastoma

35:03

or anesthesia neuroblastoma.

35:06

Then another lesion here in the, in the nasal cavity.

35:10

Here you can see that there's a pre contrast T one weighted

35:13

image, and this is T one hyperintense intrinsically without,

35:17

uh, administration of contrast.

35:19

And when you see the T one hyperintensity in a nasal cavity

35:22

lesion, then this is again one of our light bulb moments,

35:25

and this is a ano nasal melanoma.

35:29

Um, an important thing to keep in mind

35:31

for san nasal melanomas is that san nasal melanomas, uh,

35:35

when they're small especially, do not cause a lot

35:38

of bone destruction.

35:39

Sometimes they even may cause bony remodeling.

35:42

So, uh, it's important to be aware of these sort of

35:46

benign looking features of San nasal melanomas, uh, and,

35:49

and important to sort of, uh, um, look at them carefully,

35:52

especially their T one hyperintense, you know, suggest

35:54

that it, this could be a melanoma,

35:56

although it, it would not be, uh,

35:58

causing Fran bony destruction.

36:03

Then another lesion in the frontal sinus.

36:06

This time you can see that there is erosion

36:07

of the anterior frontal sinus, uh, wall

36:10

that is extension into the soft tissues.

36:13

Again, you can see on the T two weight image that this is,

36:15

this has a very dark T two appearance,

36:18

and this shows bright, um, um,

36:21

signal on diffusion weighted images.

36:22

There is a lot of, uh, reduced diffusivity,

36:25

and when you see this kind of homogenous T two darkness

36:28

and, um, reduced diffusivity, uh, you know, it's,

36:32

it's possible that we are dealing with a san nasal lymphoma.

36:35

So, you know, this is, again, important to keep in mind

36:37

that San nasal lymphoma can reduce diffusion.

36:42

Then, uh, a lot of new entities have been described in the

36:45

new WHO 2017 classification.

36:47

A lot of, you know, benign

36:49

and malignant entities have been described,

36:51

but, you know, again, coming back to the same point,

36:54

it does not change what we do as imagers in cases

36:58

of sanon nasal malignancies.

36:59

Our principles, our role remains the same.

37:02

You know, we cannot diagnose these lesions histologically,

37:05

so our role remains the same.

37:07

We have to map the tumor.

37:08

We have to describe the extent of the tumor.

37:10

So, you know, this was a nut midline carcinoma,

37:13

but our role is still the same.

37:15

We will describe that there is a lesion in the, uh,

37:17

in this nasal cavity

37:18

and the ethmoid sinus with orbital involvement.

37:20

There is full thickness skin involve, um,

37:22

subcutaneous soft tissue involvement with skin involvement.

37:26

There is intracranial extent that is intra orbital extent,

37:29

and this is more important for us to describe as imagers,

37:32

uh, to help our surgeons rather than, you know, coming

37:35

to a diagnosis of a nut midline carcinoma.

37:39

Then another lesion here, you know,

37:40

this was a bi phenotypic sinonasal sarcoma.

37:44

Um, again, you know, just by looking at this, you know, if,

37:47

if I didn't know the diagnosis,

37:48

I would say this is probably a sarcoma,

37:50

probably a chondro sarcoma,

37:51

because it has this, you know, sort of ox

37:53

and worlds, um, uh, appearance on ct, uh,

37:57

and it has sort

37:58

of this heterogeneous post contrast enhancement enhancement.

38:01

So again, that is not important for us to come, come down

38:04

to cytological diagnosis, say

38:05

that this is the bi phenotypic.

38:07

It's important for us to say that it is,

38:10

it has bilateral involvement.

38:12

There is involvement of the, um, uh, intracranial structures

38:15

that it, that is intracranial extent is more important

38:18

for us to say, rather than, um, same bi phenotypic.

38:21

And, and this was a smart B one

38:23

deficient cy nasal carcinoma.

38:25

You can see it's in the, uh, right nasal cavity with erosion

38:28

of the, uh, maxillary sinus wall

38:30

and extension into the medial, uh, maxillary sinus.

38:35

Then, uh, entities from neighboring, um, uh,

38:40

regions can also extend into the san nasal cavities.

38:43

Uh, that is an, uh, a consideration

38:46

that is important to be kept in mind.

38:48

So this, uh, lesion in the nasal cavity was a encephalocele.

38:52

It was not a sano nasal lesion.

38:54

And then, uh, dental lesions can also extend into the

38:57

sanon nasal cavity.

38:58

So this was a per apical cyst from a disease tooth,

39:01

and this extended into the maxillary sinus.

39:04

So important to keep in mind that, uh, you know,

39:06

diseases from neighboring regions can also extend into the,

39:10

uh, sanon nasal cavity.

39:13

So, uh, you know, the takeaway messages,

39:15

most San nasal masses are going to be inflammatory lesions,

39:18

you know, san nasal polyps, muco seals.

39:21

Uh, the role of imaging, our role is in mapping

39:24

of the tumor, not histological diagnosis,

39:27

and beware that, you know, uh,

39:28

lesions from adjacent regions can also extend into the,

39:32

uh, sanon nasal lesion.

39:34

Then also important

39:35

to have a checklist in mind when we are describing, uh,

39:39

malignant sanon nasal lesions, um, uh, sofa tumor mapping.

39:43

So number one, size of the tumor, then site

39:46

or, uh, multiple subside involvement, important

39:48

to differentiate tumor from secretions.

39:51

So in this regard, post contrast, uh,

39:55

Mr images are going to be very useful.

39:57

Then, um, uh,

39:58

describing anterior versus posterior maxillary sinus

40:01

involvement because it changes the tumor stage.

40:04

Then involvement of the subcutaneous tissue versus

40:07

involvement of the full thickness of the subcutaneous tissue

40:09

and involvement of the skin is important.

40:12

Then bony erosion versus frank multi compartment extension.

40:15

So, uh, erosion of the orbital wall has a lower T stage

40:20

compared to involvement of the orbital structures,

40:23

and then involvement of anterior orbital structures has a

40:26

lower T stage compared to involvement

40:28

of the posterior orbital structures.

40:30

Then, uh, erosion

40:31

of the cribriform plate has a lower T stage compared

40:34

to frank involvement of the dura

40:36

or frank involvement of the brain parenchyma than perineal

40:40

tumor spread changes the tumor stage, important

40:43

to make perineal tumors, uh, tumor evaluation as, uh,

40:47

part of your search pattern.

40:48

So look at all those fat pads at the entry

40:51

and exit sites of the different branches

40:53

of the cranial nerves, uh, V one, V two,

40:55

especially also V three,

40:57

you know, at the frame in the valley.

40:58

And then, uh, you know, lymphadenopathy,

41:00

although not common, can always be present with, uh,

41:04

san nasal cancers.

41:06

With this, I wanna thank you all, uh, for, uh,

41:10

listening patiently,

41:11

and I welcome any questions at this time.

41:13

Thank you so much for that lecture, Dr. aal.

41:15

Yes, at this time, we will open the floor for any questions.

41:19

You can submit those to the q and A feature,

41:22

and there's already a couple in there if

41:24

you wanna pop that open.

41:26

Yeah, so I do see some questions.

41:27

So the first question is, do you have any experience using

41:30

UTE imaging to visualize bony erosion or destruction?

41:34

Uh, I'm not sure what ut what, what they mean by UTE

41:41

if they could expand the, the UTE.

41:46

Do you have any experience using ultra short TE imaging

41:49

to visualize bony erosions

41:51

destruction in the head and neck tumors? Yeah,

41:53

No, I, I don't have any personal experience using ultra

41:56

short te uh,

41:57

but I, what I was saying was, I recently was at as SNR,

41:59

I saw this wonderful presentation

42:01

where they were talking about, um, you know, using MR

42:05

to solve CT questions.

42:07

You know, we routinely use CT if,

42:09

if the patient has had an MR to begin with, we just, uh,

42:13

advise them CT to look for, uh, bony changes.

42:16

Uh, but I don't have any personal experience using the

42:18

ultrasound t uh, images for evaluation of, uh, bony changes.

42:24

Awesome. How about the significance of the involvement

42:27

of periorbital?

42:28

How, how do you visualize it?

42:31

So, uh, again, you know, if it, if it's about, uh, uh,

42:35

boney involvement, then we look at ct,

42:37

but if it's more about soft tissue involvement,

42:39

we look at the mr, uh, it's, it's some sometimes difficult

42:44

to, to differentiate, but then, you know,

42:46

just the involvement of bone has, uh,

42:48

a different implication that involvement of the, um,

42:51

of the soft tissues.

42:54

Great. How do you differentiate between infection

42:57

with perceptual involvement from malignant process?

43:03

So, um, I, I think history is very important in this case.

43:06

You know, if there is an acute involvement,

43:08

if there is precept, um, um, soft tissue infiltration, um,

43:13

then it is more likely to be infectious.

43:15

But if it is, you know, long lasting, um, and,

43:18

and you know, precept, um,

43:21

I don't know if you're talking about precept skin malignancy

43:23

or um, san nasal malignancy

43:25

that ex extends into the preceptor region, you know,

43:27

that would have a different appearance then just precept,

43:31

um, cellulitis, for example.

43:34

Or if you're talking about a basal cell skin cancer,

43:37

you know, that that's totally different from involvement

43:39

of the receptor, uh, soft tissues from, from cancers.

43:44

So if you could elaborate on, you know, what exactly, uh,

43:47

that distinction is, you know, maybe I can ask it better.

43:53

I'll, um, update if that elaboration comes in. Yeah.

43:57

If cyst appeared in the cyst,

44:00

cyst appeared in diffusion images high

44:03

and restricted in a DC, how do you differentiate from tumor?

44:09

Say that again. Cyst appeared in diffusion images high

44:13

and restricted a DC.

44:15

How do you differentiate from tumor?

44:19

Well, if, if I see restricted diffusion, you know, I,

44:23

I think of a few things.

44:24

So if it's tumor, definitely I think about tumor,

44:27

but then, uh, restricted diffusion can also

44:29

be because of hemorrhage.

44:30

So, so a blood clot can restrict diffusion

44:33

and, you know, if it is a longstanding tumor,

44:36

if it's being treated or if that,

44:38

if it has undergone surgery,

44:39

I would also keep infection in mind.

44:41

So if that is restricted diffusion, then uh, uh, you know,

44:46

definitely, uh, infection is one of, uh,

44:48

one of the considerations.

44:50

Uh, but if it is a purely cystic lesion that is unlikely

44:53

to restrict diffusion, uh, by itself, you know,

44:56

it can appear T one hyperintense if it has, uh, OID

44:59

or proteinaceous contents,

45:01

but if I see restricted diffusion, uh, I think about tumor,

45:05

uh, blood clot or infection is the three

45:08

things I I think about.

45:10

Right. How do you assess the orbit if it is

45:14

infiltrated or involved from just being displaced?

45:17

Especially in the case you showed

45:20

where there's erosion of the plate.

45:24

So infiltration of the orbital soft tissues will be

45:27

associated with stranding of the fat, you know,

45:30

if there is just displacement of the or,

45:32

and usually there is not just displacement, you know, uh,

45:36

the, uh, the orbital structures,

45:37

especially the bone is, is pretty tough.

45:40

So there is not just displacement.

45:42

There is usually some involvement of at least the orbital,

45:44

uh, uh, bony, uh, wall.

45:47

Uh, but if there is involvement of the orbital soft tissues

45:50

that is usually associated with, uh, orbital fat stranding,

45:54

that is abnormal enhancement

45:56

and there is involvement of the, uh, uh,

45:58

of the extraocular muscles, you know,

46:00

they would be asymmetrically enhancing a thicken too.

46:05

How does a DC value

46:06

and profusion MRI differentiate between nasal tumors?

46:12

So, uh, there is a lot of, you know, research out there

46:15

and, and people say

46:16

that you can differentiate different cy nasal malignancies

46:19

on the basis of their a DC values.

46:20

For example, you know, I showed different cases of, um,

46:24

you know, lymphoma and sano nasal, um, um,

46:28

squamous cell cancers.

46:29

So lymphomas tend to have higher, uh,

46:33

reduced diffusivity compared to san nasal cancers.

46:36

Again, it's based on, uh, the cellularity, you know,

46:39

lymphomas are much more,

46:40

hypercellular have a higher nucleo cytoplasmic ratio,

46:43

so they have much more restricted diffusion compared to, um,

46:48

uh, compared to squamous cell cancer.

46:50

So that that's where, you know, a DC can sometimes be used

46:54

to differentiate different kinds of,

46:55

uh, standard nasal lesions.

46:58

Great. What are the characteristics

47:00

of juvenile angio fibroma on CT scan and MRI?

47:06

So JNAs are, you know, basically they, um,

47:08

happen in adolescent males.

47:10

Uh, uh, more commonly they are in the, uh, region

47:14

of the seno palatine frame

47:15

and tego palin fossa cause expansion

47:18

of the tego palatine fossa.

47:20

There is a bony remodeling.

47:21

They are very, very hypervascular.

47:23

So they show avid post contrast enhancement

47:26

and even on, um, an, um, angiogram, which is commonly,

47:30

you know, diagnostic therapeutic for these lesions,

47:33

they show a lot of vascularity.

47:36

Awesome. You got through all the questions. All right.

47:39

Thank you so much for, for being here today

47:41

and sharing your lecture, and thank you for everyone else,

47:44

for participating in this no conference

47:45

and asking all those wonderful questions.

47:48

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47:51

June 13th at 12:00 PM where the RAD Room will host a panel

47:56

with program directors

47:58

and residents talking about the radiology

48:01

match in 2025.

48:03

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48:06

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48:08

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48:10

Thanks again, and have a great day.