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

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hundreds of case-based microlearning courses across all key radiology

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subspecialties. Today we are honored to welcome Dr.

0:40

Magic Kahn for a lecture on advanced spine imaging. Dr.

0:44

Kahn completed his radiology residency at N U M C Stony Brook University and

0:49

subspecialty training in neuroradiology at Johns Hopkins University.

0:53

He is at present on the neuroradiology and interventional radiology staff at

0:57

Johns Hopkins University. Dr.

0:59

Kahan is a nationally and internationally recognized expert in spine tumor

1:03

ablation and spine cement augmentation procedures.

1:07

He has published extensively on these areas and has been invited to lecture

1:11

preside over panels, run workshops,

1:13

and moderate sessions on many national and international conferences.

1:17

At the end of the lecture, please join Dr.

1:19

Kahan in a q and a session where he'll address questions you may have on today's

1:22

topic.

1:23

Please remember to use a q and a feature to submit your questions so we can get

1:26

to as many as before our time is up. With that,

1:30

we are ready to begin today's lecture. Dr. Kahan, please take it from here.

1:35

Thank you so much for that introduction, uh, and let's, uh,

1:39

start our talk today.

1:40

So we'll be talking today about advanced spine imaging and how

1:45

this is helping, uh, triaging patients, uh,

1:50

for better care as well as better prognosis treatment

1:54

prognosis. Okay, these are my disclosures.

2:01

So we know that wearable compression fractures are basically

2:06

benign and pathological from the benign group.

2:09

Osteoporotic compression fractures are the main,

2:14

uh, reason for the fractures and constitute about 25% in the

2:19

post-menopausal women.

2:22

Trauma is a very common etiology,

2:24

especially in people less than 50 years of age. And then finally,

2:29

we have these pathological compression fractures with the usual culprit

2:34

cancers, uh, mesti to the bone and causing the compression fractures. So,

2:39

evaluation of these compression fractures diagnostically most of the time

2:44

does any diagnostic challenge,

2:48

but sometimes in few cases, you will see, uh,

2:52

as I as I as I give this, uh, talk,

2:55

that there are times when your normal anatomical imaging,

2:59

which is the backbone of imaging, uh, doesn't really help. And you need,

3:05

uh,

3:05

to go to these advanced imaging techniques to answer some of the questions that

3:10

are being posed, especially by the clinical colleagues.

3:15

Uh, you can have primary bone tumors such as myelomas and lymphomas.

3:19

They can also give rise to these, uh, compression fractures, uh,

3:25

ment of benign and malignant compression Fractures, as we know,

3:30

is very, very, uh, different. And hence,

3:32

it's very important that a diagnostically we make the distinction

3:37

between the two. Uh, most of the, as I said,

3:42

most of the time it's, it's pretty easy to make the distinction,

3:45

but sometimes it has becomes harder, especially in elderly patients where you,

3:49

you have significantly degenerative changes and all the signal changes and

3:54

density changes that happen on CT and M r I, uh,

3:59

the imaging modalities that we have available to us range from x-rays

4:04

all the way to cts PET CT bone scans,

4:08

as well as MR imaging, which is probably the mainstay, uh, of, uh,

4:13

imaging. Uh,

4:16

I am not advocating that advanced imaging techniques should be used for every

4:21

case, uh, of, uh, spinal compression fractures. Uh,

4:25

and there as there are specific indications where, uh,

4:29

these modalities help. Uh,

4:34

we talking mainly about, uh,

4:37

the diffusion as well as the profusion imaging,

4:40

and we'll touch on the chemical shift as well as some PET scan images that I'll

4:44

show you for this. So overall, spinal metastasis,

4:49

I mean,

4:49

a bone metastasis is the third most common site after lung and liver and

4:54

amongst the bone, met spine is the most common site of metastasis.

4:59

28,000 new cases of spinal metastasis happen in the

5:04

US every year, uh,

5:07

and about 15 to 20% of patients with new cancer

5:12

diagnosis. So that means stage four disease to begin with. Uh,

5:16

you see involvement of the spine.

5:21

So this is a, a a case example here. Uh,

5:24

this is a patient of mine who fell down from a bar stool.

5:28

She was in her early sixties, so had a fall,

5:32

and you can see that there is a,

5:34

a mild compression deformity that is involving the inferior endplate of this

5:39

vertebra. She had pain, which wasn't really,

5:41

was probably about four or five out of 10.

5:45

And so she was put on conservative management and she was put on our t uh,

5:48

T L ss O brace for about six weeks. Uh,

5:52

this is the M R i on the patient.

5:54

You can see that there's not much of ster edema there.

5:57

Maybe a little bit along that inferior endplate, there is some retropulsion,

6:01

which is deforming thecal sac,

6:03

but there's no significant compression or anything.

6:06

So the patient was put on this, uh, conservative management.

6:09

Her pain did not improve at all,

6:12

and in fact was gradually worsening, uh, over time.

6:17

And that's when the patient was referred to me, uh, for treatment. Uh,

6:21

and we ended up putting a spinal implant in her, as you can see here.

6:26

So we do get, I do, I do, I really do not throw my biopsy specimens away. So,

6:31

uh, I took the biopsy and then sent it out to the path.

6:35

So even after this, uh, procedure,

6:38

the patient was continuing to have some pain. Most of the time,

6:42

patients with after augmentation fetal pretty good, uh, after the procedure,

6:47

but she continued to have a good bit of pain,

6:49

and that was really surprising to me. And when the biopsy came back,

6:54

it was, uh, lymphoplasmacytic leukemia.

6:58

And going back to the anatomical imaging,

7:01

if we look at her T one weighted image,

7:05

we do see that there is infiltration, uh, of the MAR signal,

7:09

and we are losing our normal T one signal that we should be seeing in the bone.

7:14

Uh, and, and, and that was a clue that something is going on.

7:18

So she had a mar infiltrating disorder,

7:21

and she went on and got treated for her lymphoma, and her pain improved, uh,

7:25

quite a bit. So this is just incidentally found,

7:29

and I have over the years that I have been in practice,

7:32

I have at least six or seven examples of of this where we incidentally ended up

7:37

find finding cancers when we, we did not suspect on, uh,

7:42

diagnostic anatomical imaging. Uh,

7:45

now this is another patient. This is a patient with, uh, renal cell carcinoma.

7:50

Of course, there is infiltration of this vertebra.

7:53

There is some enhancement post contrast. There is, uh,

7:58

posterior, uh, cortical bulge that you can see here. So, so,

8:03

and patient was in pain. So patient was treated with, uh,

8:07

SS B R T and post S B R T.

8:11

You can see here that the pain patient developed a fracture.

8:15

So when this patient was presented in our tumor board,

8:18

this question that was specifically asked was, Hey,

8:22

is this now residual cancer that is, that has caused this fracture?

8:27

Or this is a post S B R T fracture? For those of you who,

8:32

who are not familiar, uh, with SS B R T,

8:36

multiple papers have come out that, uh, stereotactic, uh,

8:40

bone radiation is associated with an increased incidence of

8:45

post-radiation fractures.

8:47

The initial papers that came out out of Sloan Kettering put the incidents about

8:52

14 40%.

8:54

Our paper that came out a couple of years ago,

8:57

we were around 25%. Now,

9:01

most of the radiation oncology guys,

9:04

they have decreased the dose and increased the fractions.

9:08

And realistically,

9:09

I feel right now we are somewhere around 15 to 20%

9:14

range, uh, with post S B R T spinal fractures, that's also pretty high, almost,

9:19

almost equal one to one in four. So, but, uh,

9:24

going back to the question that was asked of me, uh,

9:27

it's really hard to answer this question on anatomical imaging. Uh,

9:30

it could be from tumor, it could be from S B R T I.

9:34

I really could not answer the question based on anatomical imaging,

9:38

but fortunately, by this time, we were doing our advanced imaging technique,

9:42

which we'll talk about in a little bit. And by doing so,

9:46

I was pretty sure that this was cancer related fracture.

9:49

And when we ended up biopsying this, the biopsy did prove that there was,

9:53

there was still tumor, viable tumor in this, uh, vertebral body.

10:00

So if you look at the literature, let's,

10:02

let's first look at the anatomical imaging and what are the characteristic

10:07

features of, uh, uh, uh, fractures,

10:11

benign versus pathological fractures on, on routine anatomical imaging.

10:16

So,

10:17

abnormal marrow infiltrating the pedicles is a very strong indicator of

10:21

malignancy, uh, in the, in the compression fracture world,

10:25

osteoporosis infrequently involves the posterior elements as we,

10:30

as we know, but it may involve,

10:33

so the tumor spread to the posterior elements typically occurs because the tumor

10:38

associated structural instability leading to the, uh,

10:42

leads to the fracture within the vertebral body. So here's an example.

10:46

This is a patient who had both a pathological as well as a benign

10:51

fracture. And here you can see the distinction very clearly.

10:54

Here you have infiltration of the marrow signal.

10:56

There is some extension into the pedicles at that level.

10:59

This was a pathological fracture,

11:01

while as this was a benign osteoporotic fracture where you have retention of

11:05

your normal, uh, signal. And then of course, there is enhancement at that level.

11:12

As I said, as with everything else in, in radiology, there's always a pitfall.

11:17

So, acute osteoporotic fractures sometimes may have altered signal

11:22

or may have some enhancement that extends to involve the pedicles, and,

11:27

and likely it is due to some inflammation or a stress reaction that

11:32

happens in the pedicle,

11:33

or the pedicle also has an occult fracture in it leading to those signal

11:38

changes. So you have to be very careful, uh,

11:41

about not all malignant fractures will have extension

11:45

of the infiltrated process into the posterior elements, uh,

11:49

that many of times we have just seen involvement of the body with normal

11:53

appearing, uh, uh, posterior elements, especially the pedicles.

11:58

So this is one such example.

11:59

This is a patient with a benign compression fracture post-trauma, and,

12:03

and you can see that the signal changes are extending into the pedicles

12:06

bilaterally. But this was a benign fracture,

12:11

and you can see, even see a cleft sign in this fracture,

12:14

which is a sign of benignity.

12:19

So when you have a posterior paraspinal mass, uh,

12:23

that is a short shot sign of, uh,

12:27

optical compression fracture with associated mass. And,

12:30

and no one here in, in,

12:32

in the group would ever think of calling this a benign fracture with such floate

12:37

involvement of the posterior paraspinal soft tissues,

12:40

epidural inter lateral masses. So this is,

12:42

this is a clear cut sign of a pathological fracture When you see it,

12:47

uh, usually when it is very subtle,

12:49

you have a bi lobe appearance of in involvement epidural

12:54

space because the sagittal septum in the midline pushes the,

12:58

the epidural extension of the tumor to one or the other side.

13:02

So that's a fairly characteristic appearance that you see in the ventral

13:05

epidural space. Uh, with, with, with tumors,

13:12

sometimes pathological com, I mean, uh,

13:15

benign fractures can have a bit of hemorrhage around it and can have an

13:19

interlateral uh, hemorrhage, which gives, uh,

13:22

the appearance of soft tissue prominence.

13:25

Here you can see this is a cortical break,

13:27

and you have some soft tissue prominence. But really, this,

13:31

this doesn't really, uh, is not hard to differentiate from.

13:36

Uh, pathological, uh, soft tissue mass

13:41

on tour of the posterior cortex should always be looked at. Normally,

13:45

you will have a very smooth posterior bulge, uh,

13:50

of the posterior cortex, uh,

13:52

and that when you have such a smooth convex bulging,

13:57

that is,

13:58

that is suggestive of a pathological compression fracture because the tumor

14:03

infiltrates, uh, the marrow cavity, the spongy bone,

14:06

and the axial load actually causes the bulging of the posterior

14:11

cortex. Uh, so, so make use of that,

14:15

that sign very rarely benign osteoporotic fractures can also have

14:20

posterior bulging, but most of the time, if it is a benign fracture,

14:24

you will have bulging of the superior aspect of the posterior cortex,

14:28

inferior aspect of the posterior cortex.

14:30

Or you can have an in incomplete slash complete burst fracture with that puzzle

14:34

sign that we see. Uh, so this is,

14:36

this is how an incomplete burst fracture will look.

14:39

You will not have that smooth posterior conex bulge of the,

14:43

of the posterior cortex.

14:45

Here you can see the superior aspect is bulging more than the inferior aspect,

14:49

and this is an incomplete burst where the fracture fragments are, uh,

14:54

pushing very typical of a post-traumatic or a benign

14:59

compression fracture in the spine.

15:03

This is the MR equivalent of, uh, the fractures that we just discussed. Again,

15:09

you, you do not have that smooth ball.

15:11

You do not have infiltration of the marrow that you expect to see with

15:16

that bulge in a pathological compression fracture,

15:18

you have normal retained marrow with,

15:20

with just a focal or retropulsion of a fragment. There

15:26

just an example that very rarely you can have a benign

15:31

fracture that can have a very smooth convex bulge. So that is, uh, uh,

15:36

a pitfall again that can be seen, uh, with some benign fractures.

15:43

Uh, this is a patient of mine.

15:45

They had a fall and had some neck pain, upper back pain,

15:50

had history of breast cancer, which was diagnosed about 15 years ago.

15:54

She was in complete remission, uh,

15:57

and at a fall. So everybody was thinking that, uh,

16:01

this is probably a fall related fracture. Of course, we have a convex bulge.

16:05

They're very smooth.

16:07

We have some soft tissue prominence in the epidural space,

16:11

both ventrally as well as dorsally. So that's a red flag right there.

16:16

And as you can see on this, uh, post images, uh,

16:19

that there is a dominant epidural base on the post contrast ventrally and

16:23

dorsally.

16:24

So this was actually a pathological compression fracture rather than a benign

16:28

compression fracture like years and years later, uh,

16:32

in a patient with breast cancer, uh,

16:37

a lot has been said about the location and the multiplicity of fracture in

16:42

a patient, but really, uh, it is of a limited, uh,

16:47

clinical utility. Many,

16:49

not many studies have been done to say that if you have multiple fractures,

16:54

you are dealing more with, uh,

16:56

benign fractures versus pathological fractures. Yes,

17:00

patients with severe osteoporosis can have multiple fractures up and down their

17:05

spine, but so can a patient with multiple myeloma. Uh,

17:10

so, so really can't hang your hat, uh, on

17:16

presence of these multiple fractures, uh, throughout the, uh, spine

17:23

signal changes and enhancement pattern. Of course,

17:26

we know that there is in, uh,

17:29

the malignancies and infiltrative process,

17:32

which replaces the normal T one bone signal and causes a low

17:37

T one signal. So when we are evaluating bone,

17:39

that's the T one veed image is our friend, and that's what we are looking for.

17:43

If any, there's any alteration in a normal high T one signal of the bone,

17:48

we start to think about many other, many processes that can involve the bone.

17:55

In comparison,

17:56

osteoporosis is due to decrease in the density

18:01

of the bone, and hence, uh,

18:04

there is collapse of the vertebrae much more earlier than,

18:10

uh, the infiltrative signal. So, and it, it's not an infiltrative process.

18:14

And hence,

18:16

even though the vertebral body is collapsed to a moderate extent,

18:20

you will still see normal appearing bone marrow signal in a

18:24

benign fracture. And, and, and that's the, it's,

18:28

it's a very good and easy sign to see on M r

18:32

I of the spine. When you have a compression

18:37

is be accused of that. And this is just an example.

18:39

This is a T one weighted image.

18:41

You can see that there is loss of the normal T one signal, the,

18:45

the bone darker than the adjacent disc. We,

18:49

we know that is not normal.

18:51

So this is a very diffusely infiltrated process that is involving the spine in

18:55

this patient. T two is also dark in this patient. And of course,

18:58

when we go to ct,

19:00

we see that the patient is riddled with osteoblastic metastasis up and down

19:05

or visualized spine.

19:09

Just an example here we have a patient where there is

19:14

some heterogeneous T one signal T two signal,

19:19

and, uh,

19:19

that a focal area of decreased T one

19:24

T two signal and even stir signal is decreased here,

19:27

while as in the lower level, there is three signals.

19:32

So this is a hemangioma and this is likely, uh,

19:36

a blasting metastasis, uh, on ct.

19:40

There are ways how you differentiate between a blasting metastasis versus,

19:46

say, for example, a bone island.

19:49

A couple of good papers have come up on that. And, and you really,

19:54

on ct, you measure the density, uh,

19:58

and usually metastasis is lower than

20:03

that of, uh, bone island.

20:06

The bone island is typically over a thousand ho field units,

20:10

while as metastasis are typically under a a thousand hounds field

20:15

unit, anywhere between, uh, 800 to, uh, 1000.

20:18

So that's one way of differentiating. And the other way is, is,

20:23

uh, margins. If you have more speculated margins,

20:26

you tend to think about bone island rather than smooth margins. You,

20:30

you tend to think about metastatic disease, but, uh, uh,

20:34

not many papers are out there, uh, trying to differentiate between the two.

20:39

But those two numbers that I, margins as well as the Huntsville unit are,

20:43

are two important characteristics that we use,

20:46

especially on CT to differentiate blastic mets from bone Allen.

20:52

Uh, so this was a patient with blastic met right here,

20:56

and this was a straightforward hemangioma that was right on all sequences. So,

21:00

so far so good. It's easy on anatomical imaging.

21:04

These are relatively easy cases, and we are able to differentiate, uh,

21:09

benign versus, uh,

21:11

malignant compression deformities or lesions in the spine. Uh,

21:16

this is another example of a patient who has almost moderate compression

21:21

fracture deformity. I do see a retention of my normal T one signal,

21:25

so that's a very good sign for me to say that this is more likely to be a

21:29

benign, uh, compression fracture than, than a malignant compression fracture,

21:33

and it turned out to be a nerotic fracture.

21:35

Another good thing when it comes to compression fractures of the spine is to

21:40

note for the cleft sign or the cleft sign within the

21:45

vertebral body, this is almost always a sign of benign fracture.

21:50

And whenever I see it, even in patients with cancer, uh,

21:54

I tend to favor a benign etiology rather than, uh,

21:58

a pathological fracture. Uh, so,

22:01

so make use of this sign when, when you see it, and it's actually edema that,

22:06

uh,

22:07

edema fluid that just collects in a cleft rather than the whole vertebra showing

22:11

you the bright, uh, stool signal from, from edema.

22:15

This is the CT equivalent of, uh, uh,

22:20

the cleft sign where you can take a,

22:23

take a pen and you can draw a line and you can say that there is more

22:27

compassion, more superiorly inferiorly. Everything looks pretty good.

22:31

So it's not, it's a very, uh, narrow zone of transition, right?

22:35

Rather than the wide zone of transition that you expect to see more pathological

22:40

fractures. Uh, you can see the cle Again, that's a,

22:44

that's a sign of benignity. Uh, and whenever you see it, this is the,

22:48

this is osteonecrosis importance of this is that, uh,

22:52

this has to be taken care of, because more often than not,

22:56

patient will end up developing a severe compression fracture, uh,

23:01

within next few weeks, or if this is not taken care of,

23:05

especially if they're having pain. This is kind of, sort of, uh,

23:09

an indication to me that this has to be taken care of relatively. Uh,

23:17

uh, as I said, that there is, uh, always, uh,

23:21

some pitfall in radiology. You never say never. Uh,

23:25

so this is one patient of mine that I had, uh, where,

23:29

where you can see almost a cleft sign here. Yes, there is a fracture.

23:33

Patient had remote history of cancer, uh, and,

23:38

uh, they wanted me to biopsy, uh,

23:41

this just because there was history of cancer. So I was, was very,

23:45

very reluctant to biopsy this case. But then I saw this,

23:48

that there is some paraspinal fluid also. I said,

23:51

this may be just some infection, uh, rather than tumor.

23:55

So I ended up biopsying. So I biopsied, uh, f n a,

24:00

that fluid collection that was in the interior paraspinal

24:04

region, as well as ended up biopsying the bone.

24:09

And it was really very humbling. Uh, of course, it,

24:13

it turned out to be nothing but the bone biopsy turned out to be a metastatic

24:17

ethno carcinoma. Uh, so

24:21

even after this, I'm not, I'm not advocating that, uh, you should be,

24:26

whenever you see a cleft sign, uh, you should,

24:28

you should be thinking about this case of mine. I still say that this is the,

24:33

the cleft sign, the air sign is a,

24:35

is a sign of benignity and should be kept as such,

24:39

although we do have a few case examples of where actually it

24:43

was malignant. Okay, so, so far, so good. As I said,

24:48

that was relatively easy. Now,

24:50

moving on to some of the cases where advanced imaging actually made a

24:54

difference. So diffusion related images, uh, in, in, in,

24:59

in, uh, a patient with benign osteoporotic fracture, we have bone edema,

25:04

hence more water content is there.

25:07

And so you will have more, uh,

25:10

facilitated diffusion in such a patient as opposed to patients with malignant

25:14

compression fractures. You actually have infiltration of the marrow with,

25:18

with soft tissue, and hence,

25:20

you will have a decrease or a restricted diffusion with a decrease

25:25

in the a d c value. So that's, uh, the premise of diffusion. Beated images,

25:30

as we know, as we apply brain or any other part of the body, is the source.

25:34

Same application happens in the osseous spine also.

25:39

So these are,

25:40

these are really the indications for getting diffusion images in your spine.

25:44

And now we are doing it for marrow pathologies also in some

25:49

select, uh, cases. Uh,

25:55

it really does add, uh,

25:57

or improves the detectability of the osseous metastatic lesion compared to

26:02

conventional imaging at, at, at, at times.

26:05

So what really got me to do this type of

26:10

imaging is this,

26:11

this case initially that I had years and years ago in which a patient was

26:16

diagnosed with, uh, uh, lung cancer, as you can see. And then there was a focal,

26:21

uh, spinal metastasis as you can see here. So this tumor was removed,

26:25

patient developed, uh, had S B R T for her, uh, uh,

26:30

spine involvement.

26:31

And this is the follow-up spine can see some very mild,

26:36

uh, superior nplate committee there. But overall single is well maintained.

26:41

Patient didn't have much pain.

26:43

This was a four month follow up after radiation and after surgery,

26:46

patient was doing well. Uh, this is the same patient one year later,

26:51

you may say, now, there is slightly more progression of this.

26:54

There may be some progression. Looks pretty good.

26:58

Patient was having four out of 10 pain, not, not bad at all,

27:02

was was, um, uh, some Aleve was helping with pain,

27:07

and that was about it. And the patient was, uh,

27:09

completely functional and active. Uh, but then, uh,

27:15

about a year and a half patients suddenly developed new onset, uh,

27:20

back pain. And when we put the patient for imaging, this is what we get. Uh,

27:25

so now definitely there are compression fractures here.

27:28

There's a focal area of stir signal in this vertebral body,

27:32

and these two obviously are fractured. So again, when we,

27:37

the case was presented in the tumor board, this is what was asked, Hey,

27:42

is this benign? Or do you think that there is some tumor down there? And it's,

27:45

it's related to tumor involvement. So this is your pre contrast,

27:50

this is your post contrast, this is T twos and all that. And, and,

27:53

and we really don't like to see dark t t one and

27:58

bright T two and then enhancement post contrast. So it's,

28:01

it's really hard to say, uh,

28:04

whether this is benign or tumor related. So, uh, back in the day,

28:09

we, we did not do any advanced imaging,

28:11

so we ended up biopsying all three levels and all three levels came out to be

28:16

negative for tumor. But that,

28:17

that really got me thinking that we should be doing a better job at

28:22

diagnostic imaging in, in, in, in such cases and not, uh,

28:26

going straight for, for, for biopsies.

28:29

And if we did have diffusion imaging back then, it would've really helped.

28:34

Uh, so we started to do the diffusion weighted images.

28:37

We did it in multiple straightforward cases because there's

28:42

a learning curve and you, we were learning the texts were learning,

28:48

uh,

28:48

how to get the diffusion weighted images in osseous spine because mostly people

28:53

were doing it for cord. Uh,

28:55

so it took us some time to get to an optimal B value that is

29:00

needed for osseous spine because it's different from, from soft tissue, uh,

29:04

B values. So we are, right now, we are probably around, uh,

29:08

800 B value that we are comfortable with in,

29:12

in our osseous spine world. Uh, so here you can see it's a straightforward case,

29:16

uh, but you can see very nicely the diffusion restriction in that, in that,

29:21

in that vertebra. And of course, this was, this was no brainer to that.

29:24

This is not a normal appearing, uh, vertebra. And,

29:29

uh, we started to quantitate, we, we started to put, uh,

29:33

look at the numbers, uh,

29:35

because we were ending up biopsying most of these vertebras anyway,

29:39

so we were trying to gauge like what numbers, uh,

29:44

we are very comfortable with calling pathologic versus numbers. Where we are,

29:49

we are not as, as, as comfortable calling normal. So,

29:53

so we're playing a lot with these numbers and all that. So this is a,

29:57

this is another straightforward case you can see. But, uh,

30:00

diffusion a d c very nicely. Uh, this is,

30:04

this is a, a, a good example that I'm showing here, here.

30:08

We know that this is an abnormal case.

30:10

Obviously there is probably a lesion here,

30:12

probably a maybe lesions here and there, uh,

30:16

on routine anatomical imaging. But when we do, you do the diffusion,

30:21

the, the, the,

30:22

the lesions are looking at you rather than you looking at diffusion imaging.

30:27

While as here, you would've said, and maybe this is one, this is another,

30:31

this is third. Uh,

30:34

this is a patient again with, uh,

30:36

breast cancer and complained of neck pain.

30:40

And the routine imaging that was done, uh, demonstrated, uh, uh, this,

30:45

uh, mild loss of height of this, uh,

30:48

C seven vertebra with some subtle T one hyperintense and T two hyperintense

30:52

signal. So again, the question was, uh, is this,

30:55

is this some degenerative change? Is this a fracture?

30:59

Is this a a a a met, uh, in the vertebra?

31:04

So we ended up doing diffusion. Diffusion did not show anything.

31:07

So I was pretty comfortable in saying that, Hey, this is, this is nothing.

31:11

They ended up doing a PET scan, and the PET scan showed nothing. Uh,

31:15

we did not biopsy this, uh, this patient then BV two E v,

31:19

so that this was good bv actually previously, if we did not have all this,

31:23

we might have gone in and biopsy to prove that there is nothing. Uh, uh,

31:30

so you can do, as in the brain,

31:32

you can do qualitative as well as quantitative assessment, uh,

31:36

of the diffusion slash ADC values. Uh,

31:39

many papers have come up actually trying to get, uh, uh,

31:44

a value on multiple other sequences and comparing it to the diffusion

31:48

weighted image, uh,

31:50

just to optimize the sequences and find out the numbers that people are

31:55

comfortable with. Because speaking about spine diffusion,

31:59

it's something relatively new. It's, we are still,

32:04

we are still playing with the numbers. Uh, when it comes to spine diffusion,

32:08

I mean, it's not as robust, uh, uh, uh, for example,

32:13

in the brain tumor world where we know what is what based on the a d

32:17

c quantitative values. So the tumor that has been probably more studied,

32:23

uh, in the, in the spine, uh,

32:26

diffusion world is chord. And, uh, we,

32:32

with cordomas,

32:33

anything over 1500 a D C is, is we comfort.

32:38

We are comfortable in 15, 1600.

32:41

We are comfortable in falling it more towards the main end of the spectrum.

32:46

Anything that is below, uh, 1200 ish, 1100 ish,

32:50

that is definitely the abnormal end of the spectrum. So it's,

32:54

it's the number between this 11, 1200 to 15,

32:59

16 hundreds that we still don't have a good handle on. And,

33:04

uh, so that's one of the reasons we are doing these imaging techniques.

33:09

We are tr we are getting these a, d, c numbers and then, uh,

33:13

making a call and then finally ending up biopsying those patients and, and,

33:18

and finding out which number we are comfortable with,

33:22

especially in this intermediate slash transition zone.

33:28

So a d c value around and about 1800 for sure

33:34

is a sign of benignity on the bone world.

33:37

And obviously anything under 800 is, is, is malignant. I,

33:42

I'll, I'll, I'll, I'll go up and I'll, I'm now,

33:45

if I'm seeing anything around, uh, 1100 ish, also,

33:50

I'm not comfortable in, in calling that, uh, that it's, uh, it's,

33:55

it's clear. So even around 11, 1200, I am more towards,

34:00

uh, the sinister etiology. Uh, so, so, but now I'm,

34:05

I'm comfortable. 1200 and below is malignant 15,

34:09

1600 and above is more benign,

34:12

but we are still struggling with that in between numbers.

34:18

Uh, so now let's go to some of the cases where actually, uh,

34:22

the advanced imaging techniques really made a difference.

34:26

So this is a patient with, again, remote history of breast cancer.

34:29

We have a T one, which is dark, we have a T two, which is bright,

34:34

and there was some subtle enhancement after contrast administration.

34:39

I should have put up that, I'm sorry. Uh, so what do we think now, uh, is this,

34:44

uh, malignant? Is this just a benign, uh, lesion, say,

34:49

uh, atypical heman genome? Uh, very hard to say. Uh, if,

34:54

if that question is posed to you that, Hey, what do you, what do you say?

34:58

Is this benign or is this malignant? Absolutely.

35:00

I won't be able to answer that question right away. Uh,

35:04

so in our diffusion and this, and you can see the a d c is really,

35:09

really bright on this. So this is facilitated diffusion. So after this, I was,

35:13

I was pretty comfortable in saying that this is actually a benign lesion,

35:18

maybe an atypical hemangioma, and that's exactly what it turned out to be.

35:22

It was a non-specific biopsy,

35:24

and so it was an atypical hemangioma in this patient. Uh,

35:28

this is another patient with history of lung cancer. Obviously there,

35:32

it was treated by external beam radiation because of the extensive disease

35:36

involvement. Now was complaining of severe pain in the lower back,

35:40

which was related to this, uh,

35:43

lesion that is involving the L three vertebra. So, uh,

35:49

benign or is this malignant? Again, very hard to distinguish. Uh,

35:53

there looks like there is a schmos node there, and could be, could be benign,

35:57

but really you can't come out very hard and say that this is a shmo node and

36:02

nothing else. Uh, so we ended up doing our diffusion again.

36:07

Uh, a d c was quite dark,

36:10

and the biopsy showed no tumor in that region.

36:15

Uh, not only in making a diagnosis, uh,

36:20

in some select cases, but prognostically also,

36:25

it is making a huge difference for our medical oncologists as

36:29

well as our radiation oncologists. And this is one great example of such case.

36:34

So this is a 46 year old with, uh, myeloma.

36:38

You have a focal lesion that is involving the iliac bone. Uh,

36:42

it is enhancing, and this is your diffusion, and this is your a d c.

36:47

So it's dark on a d c, it's a active lesion.

36:50

And so the patient was treated, uh, appropriately for, for,

36:55

for myeloma, and then the follow-up scan,

36:58

which was done almost three months later. So this is the post contrast imaging.

37:02

So if you were just reading an anatomical imaging,

37:06

you would be saying that the lesion is pretty much the same or may have actually

37:10

worsened a bit based on these two scans.

37:13

But look what is happening on diffusion and a D C.

37:16

The a d C is actually facilitated. So you can go out and tell your,

37:21

uh,

37:21

colleagues that the whatever they're doing is actually helping the

37:26

patient. And, and you, you see a distinct change in, in,

37:31

in, in the infiltrative manner of this lesion, and it's doing much, much better.

37:36

So, so from saying it's the same or slightly worse,

37:41

and now you're saying that, hey, whatever you're doing is really, really good.

37:44

So that, that, that makes a big difference in treatment planning.

37:49

Uh, it has helped me glide biopsies at times. So this is another patient with,

37:54

uh, two lesions. So one is in the five vertebral body,

37:57

another one is in the iliac bone. So if you had a biopsy,

38:01

obviously everyone who does bone biopsies,

38:04

you would want to go for this lesion, very easy straight shot, uh,

38:09

and, and, and biopsy this lesion. But, uh, look at the diffusion hair.

38:13

So this was not as bright, this was very bright in a d c,

38:17

this was dark while as this was bright.

38:20

So obviously it makes sense to biopsy the L five rather than

38:24

going for the chip shot iliac biopsy here.

38:27

So it can at times guide your biopsies. Also,

38:33

uh, another case, uh, of, uh, uh,

38:38

plasmacytoma that is involving the sacrum, and this is the pre-scan.

38:42

You can see the complete destruction of the sacrum, uh,

38:46

was complaining of low back pain. And this is, uh,

38:51

stir image, and this is your diffusion and perfusion. This is, this is, uh,

38:55

restricted diffusion and on treatment. Again,

38:58

stir is pretty much the same or looks even brighter than the prior study.

39:02

But look at the diffusion weighted images completely change from pre-treatment

39:07

to post-treatment. Again, uh, you can pick up the phone and give your,

39:12

uh, colleagues a call and tell them that, Hey,

39:14

this is actually doing much better than what it's looking on anatomical imaging.

39:19

So, uh, uh, a huge, a huge thing for, for patient care.

39:24

Actually, uh, we all know about the claw sign. I don't,

39:29

I don't, I don't want to go into much detail about that. It,

39:32

it's a long drawn process with modic changes. So you do get the, uh,

39:36

typical claw sign in, in, in,

39:38

in such patients versus when you have involvement actual discitis osteomyelitis

39:43

in which you will have some, uh,

39:46

restricted diffusion within the disc space rather than having the claw sign

39:49

again in modic eye changes. So that's, that's one more use of this. Okay,

39:54

moving on now to the dynamic. Uh, uh,

39:58

D c e uh,

40:00

contrast enhanced imaging is another modality that we use in the spine,

40:04

and it, it,

40:05

its the uptake of the contrast that is measured over time and

40:10

gives you the changes in the signal characteristics. Uh, uh,

40:15

it's a long scan. It takes about five minutes, uh, uh, scan,

40:19

it's a dynamic scan. You get the pre contrast, you get the arterial phase,

40:24

arterial venous phase, or the delayed venous phase imaging. Uh, so, and,

40:29

and you can come up with multiple parameters in, in, in,

40:33

in a D c E perfusion scan. Uh, so you can,

40:36

you can get the plasma volume,

40:38

which tells you about the number of blood vessels. You can have the crans,

40:43

which is a measure of the vascular leakiness,

40:47

and then you can do the wash in, wash out,

40:49

and the peak enhancement or other measurements if you're doing really a quick

40:54

qualitative measurement of your, uh, D C E perfusion scan.

40:57

These are the parameters that you would be looking at very, very closely.

41:02

Uh, let's go over a case example here. So there's,

41:06

there's a mass that is involving lumbosacral spinal canal here. It's,

41:10

it's bright on T two stir. It is enhancing like a light bulb.

41:13

Here you can see thecal sac here.

41:15

This is the ventral epidural space extending into the spinal,

41:19

into the foramen at that level.

41:23

So we were thinking about hemangioma, we were thinking about plasmacytoma.

41:26

We were ac, we were also thinking about ous, chordoma, uh, hair.

41:32

Uh, and so the patient was, uh,

41:36

was sent to me for biopsy. So as I went to biopsy this,

41:40

I came in from one side. The moment I entered the, the spinal canal,

41:45

there was excruciating radical pain down. So I stopped from this side.

41:49

I came in from the other side, uh, but patient again, complained of,

41:54

uh, extreme radical pain going down the leg.

41:56

So I really couldn't get a good biopsy. There was absolutely no way that I could

42:03

f n a and really, uh, non-specific, uh, pathology results,

42:08

uh, came back. Patient was taken to surgery. And at surgery,

42:12

it was a cavernous angio, uh, that was

42:17

this patient. Uh,

42:20

probably about six to eight weeks later, I had this patient who,

42:24

who had lower back pain and here,

42:26

almost similar appearing T two signal and enhancement involving the whole of

42:31

sacrum. We could get hold of, uh, her prior scans.

42:34

And you can see that there is a progression of this process over a period of

42:39

a couple of years, uh, with now really extensive involvement. And again,

42:45

we were, we were thinking about this usual culprits here at Hopkins.

42:49

We are like almost a, like a chordoma magnet.

42:52

So we are very careful about not missing the chordoma,

42:55

especially with such bright, uh, T two signal. But this time around, uh,

43:01

uh, so, so we, we did the biopsy, as I put my needle in, it was all blood,

43:05

so it was, it was a non-diagnostic biopsy,

43:09

but we did the diffusion imaging,

43:11

and you can see it's about 1500 A d C.

43:14

So that was good and reassuring to me. We did a profusion scan on this,

43:19

and you can see how this thing is filling up over time.

43:23

So this is the arterial phase. This is the art venous phase,

43:27

and this is the delayed venous phase.

43:28

And you can see that this is a clear cut diagnosis of, uh, a vascular,

43:33

uh, uh, etiology lesion. So this was, uh,

43:38

hemangioma and patient went for surgery.

43:41

That's exactly what they found on surgery,

43:44

was this avascular malformation. Uh,

43:49

so in, in, in, in the D c E perfusion,

43:53

you just give the contrast.

43:55

Contrast goes in from the intravascular space and the extravascular space.

43:59

And over a period of time,

44:00

some of the contrast will diffuse back into the intravascular compartment.

44:05

And this movement of the contrast back and forth is plotted

44:10

against time curve.

44:11

And you come up with all the different parameters that you use, uh,

44:15

to look at, uh, the type of profusion imaging.

44:21

As I said, a quick, uh, semi-quantitative review. You,

44:25

you look at your, uh,

44:29

which is your permeability coefficient, you look at your vp,

44:32

which is your plasma volume,

44:33

and then you look at your peak enhancement washing and washout phases,

44:37

and you can really come up with, uh, what is going on, on. And,

44:42

but if you really wanna do the whole, uh, nine yards,

44:45

then of course you have to do the decon lucid method.

44:48

You have to have an arterial input function and generate all the maps and all

44:52

that. And by doing so, you will get many more, uh,

44:56

parameters that you can look at. Uh,

44:59

the ve the K e p reflux coefficient, but typically, uh,

45:04

vp, the kran, uh,

45:07

peak enhancement washing and washout is what, what, what's needed, uh,

45:12

in the spine world. And of course, for pathological entities,

45:17

it has to be higher. While as benign entities, it'll be much lower.

45:21

So this is just the image acquisition, what we use. Uh,

45:26

so let's go over a few examples here.

45:28

So this is a new onset back pain in the patient with lung cancer. Uh,

45:33

so you can see very subtle enhancement.

45:35

The patient had some neurogenic tumor also,

45:38

which was quite incidental as you can see, uh, here.

45:42

But what we were concerned about was, was, was lesion here.

45:45

So we did our profusion imaging. Uh, this was diffusion.

45:50

It was right on diffusion, had some restricted diffusion. This was around,

45:53

if I remember correctly, it was around around 12.

45:57

So it was right at that intermediate zone. And this is the non-contrast portion.

46:02

This is the arterial phase. This is the arteriovenous phase. This was bright.

46:05

And then you can see the, uh, the kran was quite high. And,

46:10

uh, this, uh, biopsy did prove it to be metastatic disease.

46:17

Uh, this is a patient with a renal cell, and you can see, uh,

46:21

osseous metastasis that were treated with SS B R T. Uh, so,

46:26

uh, if you do fusion scan, there are multiple lesions here,

46:31

but it tells you exactly which one is still avid and metabolically

46:36

active, while others which are there on our anatomical imaging are not,

46:41

uh, metabolically active and, and are,

46:43

are well-treated lesions. Post S B R T. Uh,

46:49

the caveats that you have to be very careful about is that acute benign

46:52

osteoporotic compression fractures,

46:54

because it will have higher blood flow to it.

46:58

And so that can be very bright on if you have an acute compression

47:03

fracture deformity, that can be bright on your D C E profusion imaging.

47:07

So be careful about this pitfall. Uh,

47:11

these are just some examples, again, of a fracture with, with this.

47:15

This is another patient of ours. Here. You have two lesions.

47:19

There is lesion right here, which has some heterogeneous signal and all that.

47:23

And then there is lesion here, which is bright on almost all sequences.

47:26

So we were thinking that this is a he, while as this is, uh,

47:31

a metastatic process that in, in this, in this patient.

47:35

And when we did our profusion imaging actually both turned out to be quite, uh,

47:39

bright. So both levels were metastasis.

47:42

This patient also had a dural based metastasis up in the brain,

47:49

as with profusion, uh, with predicting prognosis,

47:53

predicting treatment response. This is another value of your diffusion imaging.

47:58

And here you can see, uh, your anatomical imaging.

48:03

You have involvement of two vertebra hair,

48:05

so completely infiltrative signal in L four involvement before

48:10

radiation, perfusion demonstrated that only L four was metabolically active.

48:14

The L three was, uh, was normal metabolically,

48:19

and this is pushed, uh, S B R T now, uh, four months later.

48:24

So we have, if, if you were comparing these two scans,

48:28

you would have said that the L four is pretty much the same. Uh,

48:32

and obviously there are new, uh,

48:34

lesions that have developed in the upper lumbar vertebral bodies,

48:37

but L four would have been like stable, uh, disease. But, uh,

48:42

the profusion actually demonstrated that the L four was now metabolically

48:47

inactive, uh, didn't show any, uh, increased perfusion parameters.

48:52

And obviously we have increased perfusion in the metastasis.

48:56

So really helps you to convey, uh,

49:00

this information to your treating, uh,

49:03

physicians that whatever they're doing is actually working.

49:06

Although anatomical imaging, uh,

49:08

is lagging behind what you're seeing from these advanced imaging, uh,

49:13

parameters. Just few other examples.

49:16

Patient where the H C C back pain here, you can see diffusion here.

49:22

High A D c value right here. This is post-treatment chemo in rt.

49:27

Obviously it has decreased, but there is still enhancement there. Uh,

49:31

but then now you have started to see facilitated, uh,

49:36

a d c value in here. So that means it's actually,

49:38

even though it's enhancing quite a bit, it's responding very well to treatment.

49:43

And this is, uh, the K trends and the vp, there's,

49:47

there's really nothing here. So excellent result, uh,

49:50

from their local treatment patient with R C C Back pain

49:55

here, you can see the diffusion profusion is quite high,

49:59

obviously on anatomical imaging, you see it, but, uh,

50:03

if just following up on anatomical imaging, you would've said that, yeah,

50:08

this is improving, but you still have multiple areas of enhancement within this.

50:12

So there is some active disease based on this post contrast and,

50:16

and stir imaging, but when you look at your diffusion and your perfusion,

50:20

there's absolutely nothing there. Uh, so,

50:23

so it's metabolically inactive,

50:25

although we are still seeing some changes on our routine anatomical imaging.

50:32

Uh, just examples, so you can, as I said that you can quantitate it here,

50:36

VP was 3.4, now 0.8, one 70 versus 30. So if you,

50:41

if you are a, if you're a person who likes numbers, you can always quantitate.

50:46

It takes absolutely more time to do all this, but, but can be done.

50:52

Uh, chemical shift artifact is,

50:55

has been in use especially by M S K colleagues for

51:00

many, many decades. Uh, in neuro specifically,

51:04

most of the neuro departments don't use chemical shift imaging, uh,

51:09

especially in the spine. Uh, I have found in, in,

51:13

in some cases, it, uh, to be, uh, frail clinical benefit. And,

51:18

and if you are able to get these imaging, and now with the newer scanners,

51:22

it's automatically generated. And if, if you haven't, just, just look at this,

51:27

and sometimes this will add value to, to what you're looking at.

51:32

And of course, we know an in phase water and fat, uh,

51:36

couple each other and you'll have high single while,

51:38

as in out of phase imaging add to T of 2.4,

51:43

you will have opposite, uh, fat and water dipole.

51:47

So they will cancel the single each other out,

51:49

and it should be all dark on auto phase imaging, and any,

51:53

any variation from that fact makes the lesion more conspicuous. Uh,

51:59

so looking at this case, obviously this is a straightforward case. This is,

52:04

there's involvement, uh, uh, of the bone here.

52:07

You can see on the in phase outer phase imaging at this level,

52:11

there's complete dark signal. There's,

52:14

there's increased signal on outer phase imaging, which you should not be seeing.

52:18

And then there are focal areas of increasing signal in this vertebra also,

52:22

which is also abnormal because you should have complete dark signal on there.

52:25

So it does, it does help at times. Uh, another case here,

52:30

you can see in phase and out of phase, out of phase, this is completely dark.

52:34

So, so there's, there's really nothing in

52:39

frequent changes rather than any infiltrated residual tumor left behind.

52:45

Obviously, all these, all these, uh, imaging, uh,

52:49

that I'm showing you both chemical shift, uh, they, they,

52:54

they cannot be read in isolation. And you had to be getting all of those,

52:59

these parameters in a patient and then, then seeing what's happening, uh,

53:04

on all these sequences rather than just seeing one.

53:08

And this is the diffusion weighted image in the same patient,

53:10

absolutely nothing there, uh, in that area. Uh,

53:15

do get a lot of F D G PET in cancer patients.

53:18

So if you are evaluating these spinal uh, compression fractures,

53:22

at times you will, you will get an answer based on your PET scan.

53:26

But typically you don't obtain a PET scan to look at or further,

53:31

uh,

53:32

evaluate just the spinal compression fracture and try to differentiate whether

53:35

this is benign or malignant. Uh, uh,

53:39

many numbers have been thrown when it comes to F D G

53:44

bone pathologies.

53:47

Usually anything between S U V of three to 4.7 is

53:51

taken as a cutoff, uh, which is, uh, towards the malignant end of the spectrum.

53:56

Some people even go and say that two standard deviation above,

54:01

uh, the liver SS U v is, is, should be taken into consideration. So there'll be,

54:06

there are a couple of papers, uh, that, that mention different s u V numbers.

54:10

Uh, when it comes to F D G, PET and bone,

54:14

obviously acute fractures can have very high F D G values,

54:18

and you have to be very careful about that fact. As,

54:21

as with all other imaging modalities, uh, that I talked about, uh,

54:26

this is a case in, in which patient had history of cancer.

54:29

He had this, uh,

54:32

lytic repairing lesion involving the posterior aspect of the vertebra. Really,

54:36

really, F D G avid, uh, ended up doing a biopsy and, and, and,

54:41

and, and, uh, it turned out to be actually tb. Uh,

54:46

this is another patient similar to one that I had shown earlier with the schmos

54:51

node. And here you can see on ct very, very characteristic schmos node,

54:55

there are some sclerotic area just inferior to the schmos node, uh,

55:00

PET scan was done. It was quite bright on PET scan,

55:03

and actually biopsy did demonstrate metastatic disease rather than just aine

55:08

looking schmos node there. So, so that's you. And, and,

55:12

and you do,

55:13

you do get your PET scan routinely for cancer or the whole body PET scan for

55:17

cancer surveillance also.

55:19

So make use of that at times when you are looking at your osseous lesions.

55:24

Also

55:27

case where I think advanced imaging really made a difference. Uh, and,

55:31

and so this is a patient who had colon cancer and had a, uh,

55:36

presacral mass. So the patient has had surgery and was radiated in this region,

55:41

and you can see both bright T one, T two there, uh, signal.

55:46

And this is the post contrast fat saturated. So everything was normal post uh,

55:50

treatment. And this is, uh, eight months later,

55:55

scan patient started to complain of some low back pain,

56:00

and that's when the scan was repeated.

56:02

And now you see this dark T one, right T two, and there's enhancement,

56:07

some signal characteristics on the opposite side, that there is no, uh,

56:13

definite, uh, uh, compression, I, sorry, a,

56:18

a fracture of the sacral ala post radiation as will look like.

56:22

The cortex seems very smooth, and I'm,

56:25

I'm showing you the actual impression from the anatomical scan

56:30

here and, uh, suggested recurrent disease, uh, at, at,

56:35

at, at that level. Uh, so, uh, I wouldn't,

56:38

I wouldn't really argue much with that because you really can't, you,

56:42

you can't really say, uh, can this be recurrent disease? Absolutely,

56:46

based on this scan, absolutely can be recurrent disease or this would be some,

56:51

uh, changes associated with radiation. So we ended up getting the patient back,

56:55

we did the diffusion. This is my A D c, this is in 2000. I felt very,

57:00

very comfortable with that number. This is my profusion scan.

57:04

There's nothing in the profusion scan that worried me. Ended up, uh,

57:09

biopsying this patient just to make sure we are not missing anything.

57:12

And the biopsy result, uh, showed, uh,

57:15

a reaction suggestive of radiation induced osteo.

57:20

So really, we had made the diagnosis based on the advanced imaging,

57:24

uh, and, and,

57:25

and just see that what we were seeing with advanced imaging is,

57:30

is actually, uh, like, uh,

57:35

this is one patient where it was a little humbling again. Uh,

57:39

so this is a patient with chondro, sarcoma of the femur,

57:42

had developed this lesion in, uh, one of the lumbar

57:47

of pain, uh, there. So this is the MR that we did and

57:53

images, it was enhancing. So we're thinking metastatic disease, uh,

57:58

there. So we ended up doing, again, diffusion,

58:03

diffusion on this. A d c value was again, 1500 ish.

58:07

Uh, this is the non portion. This is the arterial phase. And,

58:12

and this is the late venous phase, uh, based on the perfusion,

58:17

it looked suspicious based on diffusion back then. Really, I did not.

58:22

Uh, I was, I was not comfortable. We were, we were still believing that 17,

58:27

1800 and above is, uh, is good,

58:30

and anything below that falls in that intermediate zone. Now, at this time,

58:35

I'm okay with this number 1500 in bone. Uh, so we,

58:40

we were, we were favoring this to be, uh, uh,

58:44

assis rather than, uh, uh, a benign etiology.

58:49

So I ended up biopsying it,

58:51

and the biopsy demonstrated just malofibrosis, uh, and,

58:55

and, and no tumor. And going back,

58:59

my diffusion did tell me that, uh, 1500 number was there.

59:03

So diffusion was actually right, uh, about this case.

59:09

Uh, one more case example. So this is a lung cancer patient, uh,

59:13

was complaining of some pain in the iliac bone. And here you can see,

59:19

uh, that, uh, this is your PET scan. It's very epi g ever.

59:23

This is my diffusion. A d C is bright right here. And,

59:28

uh, this is scan. This is the, uh,

59:33

chemical shift, and you can see increased, uh,

59:37

signal on the opposed phase imaging. Uh,

59:41

for some reason I don't have a profusion imaging on here, but nonetheless, uh,

59:45

diffusion showed me, this pet showed me this. So there was, uh,

59:49

I was leave, uh,

59:52

there and ended up, uh, biopsy. No, this is, sorry,

59:56

this is the profusion. So the profusion also showed high, high, high, uh,

60:01

profusion parameters in that, uh, lesion. So we,

60:05

we were thinking more towards, uh,

60:08

the malignant spectrum from metastatic disease ended up biopsying,

60:12

and the biopsy turned out to be, uh,

60:15

a pageant disease involvement of this ilead bone.

60:18

But going back again,

60:21

my a d C value was very high.

60:24

So now I'm at a point where really I, if I have to,

60:28

if I have to

60:31

pinpoint one area of these advanced imaging,

60:34

I'd probably go to my a d c diffusion imaging rather than the profusion imaging.

60:39

Obviously, as I said, again,

60:40

you have to have all these parameters in place and look, uh,

60:44

all at all of them together. But if I had to pick one, I would,

60:48

I would really go with, uh, my diffusion, uh, imaging and the a d c values.

60:53

And I'll end up with this, uh, case, uh, again, uh, uh,

60:58

sacral mass, uh, kind of heterogeneous on T two weighted image.

61:03

This is quite bright. Uh,

61:07

A D C was 910, obviously this is malignant. Uh, uh,

61:12

so, uh, and, and, and,

61:15

and the profusion profusion imaging also,

61:18

it really enhanced very early and very brightly in the arterial phase.

61:22

So we were thinking about, uh, a paraganglioma here or,

61:27

or agio blastoma here. Uh, so, so that was my thought process,

61:32

but they wanted me to go in and biopsy. I biopsy it,

61:35

it bled so much that I had to actually put gel foam, uh,

61:40

needle because the blood was just porting out through my, uh,

61:44

biopsy needle. So we had to put gel foams new, so it's a very vascular tumor.

61:49

And then it turned out to be a solitary fibrous tumor on, on pathology.

61:56

So these are,

61:58

these are just some of the characteristic appearance that on, on,

62:02

on C, this is the solitary fibrous tumor early arterial phase.

62:06

This is your thyroid mets, again, arterial phase.

62:10

So when you have something that enhances in the arterial phase, uh,

62:14

you tend to think about malignant etiologies rather than if they're not

62:17

enhancing in the arterial on your profusion scans.

62:23

So, uh,

62:25

advanced imaging can play a very crucial part in differentiating benign versus

62:30

malignant lesions. As I said, that you do not need to do this for every case,

62:35

uh, because most of the time your anatomical imaging will be able to make that

62:40

distinction,

62:41

but you will be faced with cases where the anatomical imaging cannot

62:45

make the distinction.

62:46

And that's where advanced imaging techniques come into play and help you to

62:51

differentiate, uh, this. And as I showed you some cases,

62:55

examples about prognostication of care, whatever your, your, uh,

63:00

radiation oncologist or medical oncologists are doing can really help them and,

63:04

and, and, uh,

63:05

ease their confidence level after you tell them what's happening

63:10

metabolically in that area that they have, uh,

63:13

they have just few things to keep in mind when

63:17

you try to differentiate benign versus malal compression fracture.

63:21

And thank you very much for your attention. Uh,

63:26

any questions now? Lemme see.

63:32

Yeah, Dr. Conn, we're up, we're up at time,

63:33

but if you wanna answer a couple questions

63:36

Sure.

63:37

Great. I will read them off to you. Um,

63:42

how to differ lymphoma changes on a T one from post-radiation change on

63:47

Mr.

63:49

Uh, lymphoma. And so lymphoma is a infiltrative process.

63:54

So as I said, when you are looking at bone, uh,

63:58

you should be looking at your T one weighted images and any deviation from the

64:03

fact that your normally,

64:06

your T one signal should be brighter than your adjacent disc,

64:10

and any deviation from that fact should alert you to some abnormality.

64:15

So lymphoma, if it infiltrates the bone,

64:17

it'll make your t it'll make the T one single, uh, darker.

64:23

While as radiation changes usually,

64:26

typically will be bright on both T one and T two weighted images,

64:30

and they'll be even brighter than the normal T one weighted images that you

64:34

signal. Now if you develop a post-radiation fracture, uh,

64:39

then obviously you will have, again, loss of, uh, signal,

64:43

but then you should be able to see some cortical uh, breaks. Even on your M R i,

64:47

you will lose the normal dark cortical signal on Mr.

64:51

So that's how you differentiate between the two.

64:57

Okay.

64:57

How often are osteoblastic metas medi metastatic

65:02

don't have local edema and look like Bone island?

65:05

And how do you differ from Bone Island? Only on Mr.

65:08

Uh, uh,

65:11

osteoblastic mets really are devoid of, uh,

65:16

uh, edema. Uh, so,

65:19

so it's very hard to make that distinction

65:24

only based on M R I, uh, and,

65:28

and and really, as I, as I, as I alluded in my lecture, you have to have a ct.

65:33

You have to go by, uh,

65:35

bone density measurements and look at the edges of the lesion. As I said,

65:39

a little speculation favors bone island versus, uh, uh,

65:43

osteoblastic metastasis. But I, I,

65:47

I really don't think that there is any concrete literature

65:52

evidence that helps, uh, differentiate, uh,

65:56

a full blasting metastasis from, uh, uh, from, uh,

66:01

bone Island on only based on M R I Characteristics, I don't,

66:06

I don't think so. If, if someone knows about it, please let me know because, uh,

66:10

I, I really don't think that from anatomical imaging per se, there's,

66:14

you can differentiate between the two.

66:18

Should DWI I and a D C be done routinely for spinal imaging?

66:23

Uh, no. Uh, well, if you are able to do it, that's great.

66:28

It will be very helpful to you. But I, I, I don't, we don't,

66:32

we don't do it routinely in our hospital, in our practice,

66:37

because it takes time. Uh, and, uh, as I said, these,

66:42

these advanced imaging techniques should only be done for specific

66:47

cases where you're not able to answer the question, uh,

66:51

on your routine anatomical imaging.

66:53

And then you can add these imaging parameters the next time you scan the patient

66:57

for a follow-up, uh, sequences and, uh,

67:03

try to answer the question that your clinical colleagues,

67:08

but not, not routinely. Not routinely. I wouldn't, I wouldn't use that. There's,

67:13

there's still a lot of time before, uh,

67:16

we get to a point where diffusion is used like we use a diffusion in the

67:21

brain world.

67:25

Excellent. What is the timing of a dynamic study?

67:28

How many sequences do you take in a dynamic study?

67:31

Uh, so as I said, this is a dynamic scan. Uh,

67:34

so it's a five minute scan, or after you inject the first,

67:39

you, you, you do a non-contrast, uh, run through.

67:43

And then after that,

67:45

you keep on imaging that area of interest for about five minutes

67:50

so that you, you get all the, uh, over time, uh,

67:55

you get all the parameters, you get the arterial phase, arterial venous phase,

67:59

delayed venous phase. So it's just like what we do for pituitary, uh,

68:03

dynamic pituitary imaging up in the brain.

68:06

That's exactly the same parameter that we apply, uh, here. So it's,

68:10

it's a five minute scan. It takes, it takes D C e, uh, takes a longer time.

68:15

You can't really cut on time and say, for example,

68:19

use a D S C, uh, technique in the bone because D S C technique,

68:24

uh, is, is a G R E technique. And,

68:27

and G R E will just kill your scan because of the, uh,

68:31

osseous elements that are present there.

68:33

So it has to be a T one weighted sequence, uh, profusion sequence,

68:38

uh, which is, which is your D C E. But, but again,

68:41

five minutes for every D c E scan. So you're adding five minutes for sure.

68:47

Okay. All right. We'll do one more. Um, in i non-dynamic post contrast scanning,

68:52

is there a reason to scan in delayed phase if there's no early enhancement?

68:58

Uh, if you're doing a d c, that's, you will get that, uh,

69:02

for completion sake. So I wouldn't just, uh,

69:05

curtail the DC right in,

69:07

in between and just get the arterial phase in the mid arterial venous phase.

69:11

But if you wanna save time, theoretically, yes,

69:14

it is possible to not get the delayed phase imaging,

69:17

but remember I showed you a few examples of, uh, hemangioma,

69:22

which fill up quite late. So those vascular malformation, you,

69:26

you will have that degree of confidence,

69:31

uh, at times to say that, Hey,

69:34

this is actually a vascular malformation if you, if you just, uh,

69:37

cut short the imaging.

69:41

Well, Dr. Kahan,

69:42

thank you so much for your lecture today and for answering those questions.

69:45

And for everyone on, for participating in our noon conference,

69:49

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70:00

August 10th with Dr. Susie Bash for a lecture entitled,

70:03

critical Updates in the Dynamic Landscape of Alzheimer's Disease and Dementia

70:07

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70:11

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70:16

Thank you. Bye-bye.