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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 micro-learning courses across all key radio radiology

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subspecialties. Today we are honored to welcome Dr.

0:41

Sheila Sheth for a lecture entitled,

0:43

peripheral Vascular Ultrasound Venous Doppler and Challenging Arterial Cases.

0:49

Dr.

0:49

Shef completed radiology residency at Sinai Hospital in Baltimore and Body

0:54

Imaging Fellowship at the Johns Hopkins Medical Institutions.

0:58

She was on the faculty at Johns Hopkins in the Department of Radiology until

1:02

2020.

1:03

She's currently on faculty in the section of abdominal radiology at N Y U

1:08

Lang in New York City. At the end of the lecture, please join Dr.

1:12

She in a live q and a session where she will address questions you may have on

1:16

today's topic.

1:18

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

1:21

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

1:24

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

1:29

Okay, good afternoon. And this is afternoon in the United States.

1:32

In New York City where I am. Um,

1:35

and so I hope everybody can see my screen.

1:38

And so this is gonna be like a, a case-based, uh,

1:43

talk. Um,

1:44

I gave a similar talk to our fellows in the body imaging section yesterday

1:48

'cause I think sometimes it's easier to learn that way.

1:52

So just look at the cases and challenge yourself. So let's get started.

2:00

Okay, so this is my disclosure.

2:04

And so what we, uh, what I just want to review, uh,

2:08

initially, 'cause I'm gonna show some venous cases at least to begin with.

2:12

So how do we do venous ultrasound if it's very basic and I apologize,

2:17

but I just think it's important to, um, to review this.

2:20

So when we look at a venous ultrasound, I think the most important,

2:26

uh, feature is actually a transverse gray scale image.

2:30

Where here we have the common femoral vein. You have the artery and the vein,

2:34

and we want to show that with compression from the transducer.

2:38

You can nicely see on the clip. And we ask our, uh, technologists to,

2:42

or sonographers to do clips like that. The vein should be dark,

2:47

so no internal echoes and should be very easily collapsible for

2:52

from, uh, you know, just a little bit of pressure from the transer.

2:56

It's much easier to do it transverse because that you see the whole vein.

3:00

You make sure you're not rolling off the vein, uh,

3:02

as if you were doing it sadly. So that's the most important,

3:08

uh,

3:09

question in my opinion of the case to exclude a deep end thrombosis. And then,

3:14

of course, what we also look at,

3:16

we put color just to make sure the vein is filling. The wall is thin,

3:21

and then we get a doppler spectrum.

3:23

'cause we want to make sure that there is venous type flow,

3:26

which is relatively monophasic, but it,

3:29

there should be some ity from transmitted

3:33

respiratory and cardiac, um,

3:36

physic to the vein.

3:38

And that is a very important concept because that means that there is no

3:42

blockage in between a more central vein and what you're examining.

3:48

And so this is what we do. Now,

3:50

we do not do augmentation in the old we used to augment in the cap.

3:54

We don't do that. First of all, it's,

3:56

it's increased the length of the examination. Uh, it's not really necessary.

4:02

And, uh, you know, if the patient does have a clot,

4:05

there's always a small risk that by, by doing calf compression,

4:08

you can throw in a pulmonary embolus. So we don't do that anymore.

4:14

Okay, so let me start with this case. So this is a, uh,

4:17

patient who came in to the emergency department some years ago,

4:23

uh, and for left leg swelling. So here I'm showing you,

4:28

uh, still images of the left common femoral vein. So yes,

4:33

the artery is the vein. And with when we do the compression,

4:37

you can see that the vein is not compressing. And there's internal echoes.

4:41

So this is a, excuse me,

4:45

quite straightforward case of deep vein thrombosis.

4:50

However, we always look at the darker spectrum as well.

4:55

And even though, uh, it's a unilateral, um,

5:00

study, we always do both iliac veins,

5:04

external iliac veins. For comparison,

5:06

we want to compare the doppler spectrum in the, in the iliac veins.

5:12

And so, uh, and I really don't wanna take any credit for this case,

5:15

a sonographer, you know, had looked at everything and based on what,

5:19

what she saw, she did additional images. But let's see what we see.

5:24

So remember the left side is a swollen leg,

5:27

and we know there is a deep vein thrombosis,

5:30

but when we looked at the iliac veins, we can see,

5:34

and this is the external react vein.

5:37

You can see that there is a lot of ity on the right

5:42

side, but the left side is much more monophasic.

5:45

So the first question you have to answer is, which side is abnormal?

5:49

So in this case, maybe there's a little bit more ity than would expect,

5:52

but this is clearly abnormal. We should not have this monophasic, uh,

5:57

wave form in the, in the, in the legs,

6:00

in the veins of the lower extremity. You could have a,

6:04

this could be normal in a portal vein in the liver, but it's not normal in the,

6:09

in the leg. And this is, uh, it's misla. It's clearly the left iliac vein.

6:15

So based on what is going on,

6:17

we know the patient has a clot more distally, but the,

6:21

this portion of then appears open. But if you see lack of ity,

6:27

what you have to think about is that there may be an obstruction more centrally.

6:32

So we have to look in the pelvis, basically.

6:35

And so she went and looked around and this is what we saw.

6:40

So she, she looked in the pelvis,

6:43

didn't see too much and went up the aortic bifurcation.

6:47

And here you have the four vessels of the aortic bifurcation, which are patent.

6:51

However, there is a big hypoechoic mass

6:57

just adjacent to the bi, the aortic bifurcation.

7:00

And you can very nicely then show it on the coronal images.

7:04

There's a bunch of masses which are basically abnormally enlarged lymph

7:08

nodes.

7:09

And that is what was causing the leg lack of physicality

7:14

in the left external iliac vein. So yes,

7:18

the patient had a DeepEnd thrombosis,

7:20

but by thinking about the DARPA spectrum and looking around, we said, okay,

7:25

you have D V T,

7:26

but there is also something perhaps as serious or more serious going

7:31

on, you have what looks like either metastatic troper,

7:35

lymphadenopathy or lymphoma, one or the other.

7:38

And so this is why just looking at every detail,

7:42

looking at the spectrum is so important because if we hadn't done that,

7:46

we would've sent a patient, we would've been treated for D V T,

7:48

but they would've missed.

7:50

So what is probably the underlying cause of the deep vein thrombosis?

7:54

This patient, uh, ended up having metastatic prostate cancer, but that,

7:58

you know, that doesn't matter. Once you find this, then you'll do a full workup,

8:02

you'll do CT scan or M r i, et cetera. Okay,

8:06

so this is a, uh, a different case, a companion case,

8:12

uh, because I really want to stress this point.

8:14

So this was a 42 year old woman who presented with abdominal pain and left lower

8:19

extremity swelling.

8:21

And about five years prior to her presentation to the emergency department,

8:25

she had had a radical hysterectomy for cervical cancer.

8:31

So we did a, you know,

8:32

they requested a duplex venous ultrasound of the lower extremity.

8:37

And in this particular case, all the vessels were patent.

8:43

So here is the right side, again, by now, you know what,

8:48

I'm driving it right, this, there is normal ity.

8:52

This is an old case. So we were doing augmentation at the time,

8:55

we don't do anymore.

8:56

So there is normal sic flow in the right external iliac vein in the right common

9:01

femoral vein. And on the left side,

9:05

you can see that there is very monophasic flow.

9:08

And if you have both sides to compare, that's really so striking.

9:11

So I think it's important to always look at the contralateral side, uh,

9:15

at least one doppler spectrum, which is a routine.

9:19

And then when we looked at the, at the vein itself, uh, the,

9:23

the right camera fain was compressing. The left was also compressing.

9:27

It was a little hard to compress with the patient had pain,

9:29

but basically the veins completely normal, normal size,

9:33

no e echogenic material within it. So again, we said there is no

9:40

D V T,

9:41

but because we saw this lack of ity, we said,

9:46

okay, well we don't see anything, but the patient needs a CT scan,

9:51

uh, to see if there is anything more centrally. So here are patients. Um,

9:57

so again, just to recap, uh, bilateral common femoral veins are compressible.

10:01

There is flow demonstrated in both, uh, external iliac veins. However,

10:05

there is what's more important the dampen flow in the left external iliac vein

10:09

with lack of normal ity. So let's look at the next step with a CT scan.

10:14

And here you can see on the

10:18

axial images as well as the corona images that the,

10:22

the vein itself is hidden, maybe a little compressed.

10:25

But what is really important,

10:26

this patient has a necrotic mass in the left pelvic sidewall

10:32

compressing the external iliac vein.

10:35

And that is the cause of the dampen flow in the left external

10:39

iliac vein. So in this particular case,

10:42

if we hadn't paid attention to this dampened flow,

10:45

we could potentially have sent a patient home because we did not see a D V T.

10:51

And now this patient that turns out was lost to follow up.

10:55

And unfortunately for her, what this was,

10:57

was a big metastatic nodal mass from squamous cervical cancer. And we know that,

11:02

uh,

11:02

squamous cell metastasis or often necrotic such as this node.

11:07

Okay? So very, very, very important to pay attention to the doctor spectrum.

11:16

And so this is basically what we need is recognize the dampen flow

11:21

on one side. In a vein,

11:23

you have to think about a more central pathological process.

11:28

So this is an upper extremity case.

11:31

So upper extremities are even a little bit more challenging because, um,

11:36

your direction of flu is not always, uh, as obvious. So let's go step by step.

11:40

This is a patient who had left upper extremity swelling.

11:45

And so I have the left interal jugular vein here and the right interra jugular

11:50

vein for comparison. So if we look at the right inter the normal side,

11:54

the non swollen side, you can see that there is phasic flow.

11:57

And in the upper extremity in particular, you should always have phasic flow.

12:02

And now let's look at direction of flow. So this is a sagittal image.

12:07

So the, um,

12:09

right interal jugular vein should flow towards the heart. So here's head,

12:14

here's feet.

12:15

So it should flow towards the transducer because it's going down towards the

12:20

heart, where in the neck. And so the flow should be then red, which is this.

12:24

So towards the transducer. Now,

12:27

you can see now that on the other side, the,

12:31

my settings are exactly the same, but what do I see?

12:35

I see that the left jugular vein, internal jugular vein has some flow. However,

12:39

the flow is extremely dampened, almost, you know, very,

12:43

very slow flow compared to the normal right side. And in addition,

12:48

the flow is reversed because normally the left internal jugular vein should

12:53

flow towards the heart. So it should be towards the transducer,

12:56

it should be red, and yet it's reversed. Okay? So now we have to see,

13:01

okay, well why is the flow reversed?

13:05

So what we try to do now, that's not always easy,

13:08

but if you have an abnormality, it's important to try to look in the,

13:13

um, in the upper media sternum as deep best you can. Now,

13:17

you're not always going to be successful, but what we do,

13:20

and you can see that we switch transducer from a linear transducer here to a

13:24

curve linear transducer, because I basically put the transducer, I'm sorry,

13:30

in the,

13:31

in the stronger notch or just below the clavicle and angle down as much as we

13:36

can. And again, we did the right side for comparison.

13:39

There is good flow in the denomin vein,

13:42

and on the left side there's a lot of aliasing.

13:45

Now the aliasing may be because my scale is very low,

13:48

but this is the only way I could really penetrate deep into the upper

13:52

mediastinum. But when we put the doppler,

13:56

and this was angle corrected, you could see that there is very,

13:59

very high velocity in that region.

14:04

So basically we concluded that this patient has a venous stenosis.

14:08

There is a stenosis of the left in nominated vein

14:14

near its convergence with the internal jugular vein.

14:17

And that is why you had dampen as well as reverse flow in the left internal

14:22

jugular vein. So we have to do all these gymnastics.

14:25

Now you're gonna tell me why is that?

14:27

So just think about why would a patient have stenosis? Okay,

14:32

so the patient had stenosis because the patient had a pacemaker,

14:38

which is a risk factor for upper extremity

14:42

stenosis as well, venous stenosis as well as upper extremity D v t.

14:47

The same is true for patient who have large in dwelling catheters for,

14:50

for hemodialysis. So it's really,

14:53

otherwise upper extremity thrombosis are not that common

14:59

compared to the, uh, lower extremity. But usually there is a, there is a,

15:02

a risk factor, a indwelling catheter, PICC line, or a pacemaker.

15:07

So because we picked up that stenosis of the lefty nominated vein that the

15:11

patient was treated with balloon angioplasty and her left upper

15:16

extremity swelling got much better.

15:21

Okay? So again, abnormal physicality is really, really important.

15:26

I know I keep repeating this, but I think it's really, really important to,

15:29

to think about it, um,

15:32

to at least look and make sure you,

15:36

you either look or recommend another study to make sure the patient doesn't have

15:40

a central abnormality, um,

15:43

and then use a contralateral vessel for comparison.

15:46

Because inherently the, the ity will vary among different subjects.

15:51

A patient has heart failure but will be much more physic. Some patients have,

15:56

you know, relatively slow flow with lack of ity,

15:58

but at least it should be relatively comparable from side to side.

16:04

Okay? It's important to assess physicality during quite respiration.

16:09

Now of course, there are pitfalls.

16:11

If the patient has very large collaterals that are bypassing

16:16

the area of thrombo and narrowing,

16:18

then the transmission transmitted possibility may still be present because the,

16:23

the, the, the flow will just go through the large collateral.

16:25

So that's obviously a, a pitfall.

16:28

The other thing is a patient has bilateral dampen phy uh,

16:32

ity because there's a ma big mass, for example, sitting on the I V C,

16:35

then it might be difficult to recognize whether it is normal for this patient or

16:40

abnormal. Okay?

16:44

So this is another kind of acute case, I think.

16:47

So this is another patient who had white upper extremity swelling. Now here,

16:52

the diagnosis is pretty obvious why this patient has swelling.

16:56

The right intra jugular vein is markedly expanded and there is an echogenic

17:01

material within it, and it doesn't compress, right? So that's, and this, this,

17:05

this quad is almost floating in the vein. Okay?

17:09

Now then we look at the direction of flow.

17:12

So this is the subclavian artery for comparison, the subclavian artery,

17:17

like all peripheral arteries. And we talk, we'll talk, uh, uh,

17:20

about it a little bit later. In the, in the, in those cases,

17:25

a peripheral artery should have nice phasic

17:30

waveform or at least biphasic waveform because it is supplying

17:35

muscles, which is a hive resistance fat as opposed to, for example,

17:40

the liver or the brain, right? So you need to see this high resistant slope.

17:45

But when we look, so we on the right side, so the, um,

17:51

the, the, the white subc artery is, is,

17:54

is here when we look at the white subclavian vein.

17:58

Now the vein should be draining towards the center.

18:03

This is a transverse u. Now the heart will be here,

18:06

so it should be draining towards the heart.

18:08

So it should be going away from the transducer,

18:12

and yet it is blue.

18:14

So that means it is going away from the transducer Y because there is a

18:19

more central blockage.

18:21

The artway should be going mostly this part towards the

18:26

arm. So it should be going towards the trans. Okay? So here,

18:31

uh, we can see that there is, so there is a clot, but what is the explanation?

18:36

So this is in the internal jugular vein.

18:37

What is the explanation in the subclavian vein? Well,

18:42

then I have to worry. What we would suggest is, first of all,

18:46

what we should do is look at the other side. And if it's similar,

18:50

then you have to suggest that there is a central, um,

18:55

blockage occlusion of the SS V C. Uh, I'm not sure we looked at the other side,

18:59

but what I,

19:00

I wanna share is this CT scan who basically shows that there is

19:05

a hotspot in the liver, okay?

19:08

There's marked enhancement of what used to be the quadric lobe.

19:12

And this is a telltale sign, which was initially,

19:15

I think describing nuclear medicine, the hotpot in the liver.

19:19

And that indicates that there is an occlusion of the SS V C,

19:23

and then there's some collaterals bypassing the,

19:26

and you can see here a bunch of collaterals even on this patient subcutaneous,

19:31

uh, tissue here and on the, on the Corona as well.

19:35

And so that is an indication that there is a more

19:40

central SS V C O collusion,

19:45

okay? This is a very rare case. This is the only case of this I've seen.

19:50

And I, I, I mean, I didn't read this case, one of my colleagues did,

19:54

but I'm not sure I, I didn't know about this entity. So let me share with you.

19:58

So this is a patient again, with right

20:01

lower extremity swelling with back in the leg now,

20:05

and there is the cystic area,

20:09

which is apparently adjacent or very near the right external iliac

20:14

vein. And it seems like there is very turbulent flow right in the vein. The,

20:18

the, um, the velocity is probably fif at least 50 centimeters per second,

20:23

which is high, and you can see an area of ine right there.

20:28

Okay? And so again,

20:32

when we compare side to side, my favorite thing,

20:37

you can see on the opposite side there is good ity,

20:41

but there is diminished ity on the right side. So again, asymmetry,

20:46

and we already knew that there was a problem here. So what is this cystic area?

20:50

Well, it is a,

20:52

this is a patient's CT scan that shows basically that there is a

20:57

cystic lesion,

20:58

lower attenuation lesion in the vein or compressing the,

21:04

um, right external iliac vein. The other side is normal,

21:08

okay?

21:09

And so this is a very rare case of a cystic advent tissue disease

21:14

of the common femoral vein,

21:16

which basically is a mucin containing cyst in the wall of the vein that

21:22

results in compression of the vein. This mucinous containing cyst can, can,

21:27

can occur in the arter as well as the venous system.

21:30

And they're actually more common in the arterial system, uh,

21:33

supposedly in the palli al artery. And what there is,

21:36

is a accumulation of gelatinous fluid in the wall of the vein that

21:41

develops a cyst and causes compression.

21:44

So if it affects the popal artery,

21:46

if the patient will have symptoms of claudication,

21:49

if it affects the vein as in this case you have dampen flu and you may even

21:54

have deep vein thrombosis. And the treatment which was offered to this,

21:59

this patient was actually surgical management. You have to remove it, um,

22:04

to, to treat the patient. Okay?

22:10

Now this is a 40 year old woman who presented with acute

22:15

onset of left lower treat swelling and throbbing pain.

22:17

She was previously completely healthy and her only important past medical

22:23

history was that it distorted oral contraceptive a month ago.

22:27

So of course the, the, the suspected D V T and we,

22:32

we did, uh, the D V T study.

22:34

And so if we look at the left common femoral vein, again,

22:38

you know that this is without compression, this is with compression,

22:42

the vein is expanded, has some microgenic material and is not compressing.

22:46

So the patient does have a left common femoral vein, D V T,

22:51

and she also had, I'm not showing this, but she had extensive, uh,

22:55

d v tout the left lower extremity. Now,

22:59

we were able to look very, very carefully.

23:03

That's not part of our routine, but because of her history, we decided to,

23:08

to look a little bit more deeper in the pelvis.

23:11

So this is a longitudinal view of the iliac vein.

23:14

So more central above this, and this is completely occluded.

23:21

And then what she was, you know, we were able to,

23:24

to see very deep and we,

23:26

so we looked for the I V C and the bifurcation of the iliac veins.

23:31

And you see here that the IVCs patent,

23:35

but the left iliac vein is completely occluded.

23:38

Even the left common iliac vein is, is occluded.

23:42

So now what is going on? Yes, the patient has a D V T, but it's probably

23:48

not enough to just say that because we need to understand why the patient has

23:53

this D V T otherwise healthy. Okay?

23:56

So what this patient has is,

23:59

and the white blue extremity venous doppler was normal or she doesn't ha she

24:03

didn't have any other risk factor like, uh, hypercoagulable states,

24:08

but because her age and the fact that she had extensive

24:13

unilateral left low extremity D V T including involving the left

24:18

common iliac vein, we was the possibility of Mayer syndrome.

24:23

And that's important because the management for this patient is not just

24:27

anticoagulant, but you need to address the root of the problem. Okay?

24:32

So what is maternal syndrome? It is an compression of the iliac vein,

24:37

iliac vein compression syndrome.

24:39

It usually happens on the left side because the pathogenesis,

24:42

at least the thought is that there's a obstruction of the left iliac vein when

24:47

it is caught between the right iliac artery and the spine.

24:51

And because of the pulsation of the right iliac artery,

24:55

the one of the theories that the formation of little mini trauma to the vein and

24:59

the formation internal webs, uh,

25:02

and the patient can either present acutely like this patient with acute

25:06

extensive D V T or they can have chronic symptoms of venous insufficiency,

25:11

which can be quite debilitating. And remember, usually these are young patients,

25:15

usually young women.

25:17

So the typical patient is a woman in the second or third decade of life, uh,

25:22

more commonly affected the left common iliac vein. And this,

25:26

this maternal syndrome, if you look at the literature,

25:29

is diagnosed in probably two to 5% of patients with lower extremity venous

25:34

disorder, but maybe under reported because we don't always think about this.

25:38

And of course, risk factors are oral contraceptive, pregnancy,

25:42

and to confirm the diagnosis, CT or MR is very helpful.

25:47

And what you're going to see in this, typically these patients are at risk.

25:51

This is a different patient.

25:52

There is a very narrow space between the iliac

25:57

artery and the right iliac artery and the, and the spine.

26:01

And you can nicely see here that the left iliac vein is getting,

26:05

complace is squished between the iliac artery and the, the,

26:09

the vegetable body here.

26:11

So this patient also had extensive deep end thrombosis, uh,

26:16

as you can see here with a vein expander. Okay?

26:19

A very important thing to think about in the right, uh, patient.

26:24

Okay? So, uh, what,

26:25

what we look at for a very small diameter of the left commonly vs origin,

26:30

like I just showed you, just behind the white iliac artery.

26:35

And so the management,

26:36

it's very important to make the diagnosis because in addition to,

26:40

to treating the D V T, um,

26:43

we can first of all try to do thrombolysis in the acute phase to try to avoid,

26:48

um,

26:49

the patient developing venous chronic venous insufficiency and

26:54

the treatment to prevent recurrences to put an iliac vein stent placement.

26:58

So that's why making the specific diagnosis of meth or syndrome

27:03

can really be very, very helpful to your patients.

27:10

So again, this is the challenge here is just that even though you haven't,

27:14

that's what I've hope hoped to show you in these multiple cases.

27:17

Even you have classic finding or D V T, just don't stop there,

27:21

just think about why the patient has a D V T and if

27:26

there's a normal variant in this patient who may have, uh, have,

27:29

have specific therapeutic in intervention and improve the quality of life for

27:34

these patients. Okay?

27:38

Now this is a, a different case.

27:40

This is a 62 year old man who presented with low extremity,

27:44

left lower extremity pain to the emergency department.

27:47

He was a poor historian in the history of substance abuse.

27:51

And basically they said, okay, as left lower extremity pain,

27:55

we are gonna get a left lower extremity venous doctor.

27:58

And he actually came twice. He came once, uh, the,

28:03

I'm not showing you this, this images and uh,

28:06

it was just read as no evidence of event thrombosis,

28:08

but the patient had worsening pain. So he came again. And this time again,

28:13

uh, these are the wonderful sonographer from Johns Hopkins who you know,

28:17

are really, uh, you know, really, uh,

28:20

I mean we have excellent sonographer at N Y U too.

28:23

But this is a case from Hopkins where the sonographer said, okay,

28:28

well let's look at the left al vein, right?

28:31

So the vein is fine, the vein is compressing.

28:36

But then she noticed that, oh my god, what is going on in the artery?

28:41

The vein is clear here,

28:42

but it seems like there is a clot there is filling the entire

28:47

left popal artery.

28:49

And the way this is moving the vein should pul the artery, I'm sorry,

28:54

should puls out like this and it's pulsating this way.

28:57

So that is a sign that there is an occlusive clot in the

29:02

left pop tail auto.

29:05

So basically what happened is that they had maybe misinterpreted the

29:10

patient's symptoms, the patient didn't communicate what was wrong with him,

29:14

and they just ordered the wrong study. But fortunately,

29:18

the second time it was picked up that the patient had a clot

29:23

occlusive clot in the left paral artery also, then we,

29:27

we did a portion of the, the, the arterial study.

29:31

And so this is the other side, the right side,

29:34

which shows in normal filling popal artery with a normal

29:39

phasic flow.

29:41

And then we looked at the dorsal is P artery also nice strong

29:46

phasic flow. When we looked at the public artery,

29:49

there is no flow at the level of the clot.

29:51

And the left dorsal EDUs is extremely attenuated with very no

29:56

flow. So the more of, so this patient ended up having,

30:01

uh, a completely, a complete arterial doppler examination,

30:06

confirmed that a, a complete occlusion of the distal left paral artery, uh,

30:10

and the patient had to have an emergency, uh,

30:14

thrombectomy and revascularization of that low extremity,

30:18

otherwise you would've potentially had, had to have an amputation.

30:23

So the moral of the story here is that it's important when not to have tunnel

30:28

vision, but look around, uh, you know,

30:31

basically our job is to problem solve the patient, patient has symptoms or, or,

30:34

and we need to figure out why. Okay? So this is, uh, another,

30:40

uh, similar example, uh,

30:42

where the patient had a right no flow in the right femoral artery.

30:46

And I just want to show you what,

30:50

what happens when there is an occlusion in gel system.

30:54

So this is in the femoral artery. So when we look more centrally,

30:58

so above the level of the occlusion,

31:02

then you have good strong, this is not really, uh, tri,

31:07

this is a little bit phasic. There's a little bit too much flow in diastole,

31:10

but still there's a strong systolic up stroke, right?

31:13

When you look distal to either an occlusion or very

31:18

significant stenosis,

31:20

then you're gonna have this classic tardis vis waveform.

31:24

And this is why I have this, um,

31:27

this case here to show that there is lack of a sharp,

31:31

normal systolic up stroke. It's too, um,

31:35

the slope is too slow and there is a lot of diastolic flow because there is also

31:40

very turbulent flow, okay?

31:42

So this tardis parvis waveform,

31:45

you're gonna see more distal to either an occlusion

31:50

or a severe stenosis, and you can apply this in the leg,

31:55

you can apply that in the liver, in the kidney, uh, wherever.

31:59

This is a very, very important tardis progress,

32:04

abnormal waveform to, to register to keep in mind. Okay?

32:10

And so one more case that I want to share with you before I move more to,

32:15

uh, some arterial abnormalities is, um, this case. So again,

32:19

it's very important to avoid tunnel vision. Um,

32:24

and you know, and just look around, I showed you abnormal lymph nodes,

32:27

fluid collections, arterial abnormalities when you do a T V T study.

32:32

Okay? So now, and again, I a full disclosure,

32:37

we don't do a full al evaluation. Uh, we didn't do it at,

32:41

at Hopkins, we don't do it N Y U, that's for the vascular lab. So we don't do,

32:46

uh, a, uh, ankle brachial indices and, and stuff like that.

32:49

But what I wanna share with you is maybe abnormal doppler spectrum

32:54

that also indicate either occlusion or stenosis.

32:58

So if you have arterial occlusion at the segment itself,

33:03

you have, you can either see the clot or,

33:07

and often the clot can be echogenic and you will have no flow

33:12

proximal to the occlusion. So more above the occlusion,

33:16

more centrally, uh,

33:19

you are gonna see a sharp systolic up stroke and the flow should be often should

33:23

be biphasic. Sometimes it's monophasic. So you have a hint.

33:26

This is a femoral vessel, right? So the,

33:29

it should be phasic very high resistant flow. So you may have a hint,

33:33

but maybe this is not normal,

33:36

but you have a short systolic up stroke and again, distal to the occlusion.

33:40

So this is more distally,

33:43

you'll have this parve starters wave form,

33:47

and that's an important thing to keep in mind. Okay,

33:52

so just a word about acute ischemia.

33:56

I've shown you a couple of example,

33:58

really the viability of the limb because the patient does not have time to

34:01

develop collateral vessel.

34:03

So patients usually typically would present with acute severe pain.

34:07

You may have discoloration of the limb,

34:09

you may have decrease of or absent distal pulses,

34:13

and that's really a surgical emergency, right? Uh,

34:16

the patient needs to see a vascular surgeon immediately. Some, uh, etiology,

34:21

embolus, uh, thrombosis dissection,

34:25

which can be spontaneous or posttraumatic and much less commonly vasculitis

34:30

or low flow state,

34:31

that's a bit less common because often times this patient have time to develop

34:35

some collateral vessels.

34:40

Okay? So this is another patient given me, given to me by my friend dr.

34:44

But again, in the upper extremity, same concept.

34:49

So if you look at, so this patient had a, um,

34:54

digit dis acute fifth digit pain and discoloration on

34:59

the left side. And so when they did the doppler,

35:05

um, we couldn't really see centrally, right? They couldn't see centrally.

35:08

But this is what was noticed that's very important is that in the axillary

35:13

artery as well as the radial artery,

35:16

you have a TARDIS harvest wave form.

35:19

This should be a strong phasic flow,

35:23

which sharp systolic up stroke and reversal flu diastole, we did not see that.

35:27

So based on that alone,

35:29

because they couldn't see centrally where the problem was,

35:32

ultrasound cannot reach there. But based on that, they said,

35:36

look at this patient may have a more central occlusion or stenosis.

35:39

The patient needs a C T A. And so when they did the C T A,

35:43

you can see that in the subclavian artery here,

35:47

there is a clot with near complete occlusion on the mip, very nicely shown.

35:52

So again, this is why I think what DR was so important.

35:55

It's not just to see there is flow and no flow 'cause the, the,

35:58

the arteries are patent here, however,

36:01

analyze the dropper spectrum and from that infer that there may be something

36:06

that's beyond what you can see and recommend the appropriate study.

36:12

Uh, this is a case of, of, uh, dissection. Um,

36:18

and, uh, you can have a post-traumatic, uh, dissection, uh,

36:23

with, with very little flow, um,

36:27

in the left common femoral artery, no, for the left femoral artery,

36:31

you don't always see the dissection flap. Uh, and sometimes,

36:35

and I've seen this case also, uh, these kind of cases in the,

36:38

in the co in the common quad artery, uh,

36:42

sometimes you can have posttraumatic dissection, uh,

36:45

and co and the dissecting flap then occludes the vessel.

36:51

Okay? So I noticed that, um, you will,

36:55

you will may have more of these cases if you go to the next, the, the,

36:59

the talks that's given next week. But I'm going to show you some complications,

37:03

uh, related, as related to the R T L system.

37:06

So this is a 67 year old man who presented with pain and a puncture side after

37:10

he had a corona angiogram.

37:13

And so we did a writing window ultrasound with doppler and what do

37:18

we see? Well, here,

37:21

there is at the puncture site an area

37:26

of marked aliasing, right?

37:28

This is the color equivalent of a brewery because basically there is

37:33

tight stenosis as you can see here with a,

37:36

with a angle corrected velocity going up to 440

37:41

centimeters per second. And so, uh,

37:45

there is a very tight stenosis at the puncture side, uh, more,

37:51

uh, distally. You have, again the monophasic flow that I've talked to you about.

37:55

Maybe it's not quite a sardi, but certainly having this, uh,

38:01

forward four diastole e femoral artery is abnormal. Now,

38:05

it may be that it's caused by this stenosis or maybe the patient,

38:08

remember the patient like called me angiogram. So he may have,

38:11

he may be a vascular, he may have multis disease and he could have,

38:17

um, other, other vascular causes, you know, to, to cause that.

38:22

But anyway, this is a, uh, abnormal flow in the femoral, uh,

38:27

auto. Okay? So in this case,

38:32

uh, there was a brew and elevator stenosis elevated velocity of the right common

38:36

femoral artery consistent with the severe stenosis. And so again,

38:41

change from a normal phasic flow in a peripheral artery to a

38:46

monophasic flow may indicate a more proximal significant stenosis or occlusion.

38:50

That's something that's very, very important to remember.

38:54

And this is not quite a progress tus, uh,

38:58

it maybe because the patient doesn't have occlusion but have severe stenosis.

39:02

Nevertheless,

39:03

that is an indication that you need to think about something happening more

39:08

centrally. Okay,

39:13

what about this case? So here you have, um,

39:20

a tight velocity here. Um,

39:24

also in the, um, in the, in the

39:29

internal on, I'm sorry, right iliac artery. Okay?

39:35

And he, he has the other side for comparison again.

39:39

So here you see the velocity in the artery is 75

39:44

centimeters. Second in the white common femoral artery in the iliac artery,

39:48

you can barely see it, but the velocity is extremely high.

39:54

Okay? So there is an and and there is there,

39:58

there are plaques. So there is a big gradient. Okay?

40:01

So what's you need to look for when you look at stenosis,

40:05

you look for a gradient. Uh, and in this particular case,

40:10

the ratio between the right internal area artery with the right common fem

40:14

artery was more than, uh, two to five to one.

40:17

And that's an indication that there is a severe stenosis because of the

40:21

gradient. Okay,

40:24

so what other criteria for stenosis might always think?

40:28

I don't like remembering numbers. I say keep it simple.

40:31

If you have a systolic velocity gradient of more than two

40:36

to one or 2.5, two, one,

40:39

you have to think about the possible of stenosis in between those two segment of

40:43

50% of more. And again, if you're not sure, always look at the other side.

40:52

Okay?

40:52

So here this is a 67 year old woman who had complex

40:57

cardiac history, uh, underwent cardiac catheterization,

41:01

which was complicated by brainin abscess with M R S A.

41:05

She also had DDTs. Anyway, she had a very, very complicated history.

41:10

And we were doing a lower extremity venous doctor, right?

41:13

Removing the I V C filter. So what do we see here? Well, the,

41:18

the veins were okay,

41:20

but there is here a focal outpouching

41:25

coming off the femoral auto, okay? And the vein here,

41:30

this segment of the vein was patent, but there is a focal outpouching here

41:35

and with, you know, maybe some internal echo. So what are we dealing with? Well,

41:39

we're dealing with an aneurysm, an aneurysm coming from the artery.

41:44

Now what is important here? So that's a first diagnosis.

41:48

There is a auto aneurysm, there's an expressing outpouching,

41:53

there's yang yang color doppler within the lesion that's classic for

41:58

a aneurysm or pseudo aneurysm. Uh,

42:03

there is normal phasic fcom femoral artery, normal sic foc common femoral vein.

42:08

And so you see that there is an aneurysm. Now what you have to decide then,

42:12

is that a pseudo aneurysm or is that a mycotic aneurysm of the white common

42:17

femoral? It's really difficult to see just based on those findings.

42:21

I think we can favor the fact that the pseudo aneurysm because it's an eccentric

42:25

outpouching as opposed to more fusiform dilatation of the artery.

42:30

Uh, and here the history is very, very important.

42:34

We know that she had M R s A infection and therefore you are concerned about

42:39

a mycotic aneurysm.

42:40

And that's very important because it's gonna be treated very differently if it's

42:44

just a pseudo aneurysm. Uh,

42:46

it could be potentially just injected with thrombin.

42:49

And this is a CT in this patient, again,

42:51

showing the pseudo aneurysm with surrounding soft tissue. Um,

42:57

stranding here, you can see it on the map. And so if it's just a plain,

43:02

uh, pseudo aneurysm, then um, you can treat it with thrombin.

43:06

But if you're suspecting a mycotic aneurysm,

43:10

then you have to re reset it surgically, which is what was done in this patient.

43:15

So what a pseudo aneurysm, basically pseudo aneurysm,

43:19

I contain art wall defect that affect all layers of the artery.

43:24

Usually you see a neck from the rtl, uh,

43:27

defect and the vast majority are due to catheterization, right?

43:32

Uh, you can have non nitrogen trauma, but the vast majority are due to, uh,

43:37

catheterization. And the management, as I discussed it,

43:40

you can do ultrasound guided compression,

43:44

you can do till it's thrombo. You can do thrombin injection.

43:48

And if nothing of this worked, you can do surgical repair. But in this case,

43:51

because we were concerned about the presence of a infection,

43:55

this had to be surgically uh, resected. Okay? This is another example.

44:00

This is a more plastic example of a pseudo aneurysm.

44:05

Uh, this, this, this patient had a, some sort of catheterization.

44:09

So here's the, uh, still image,

44:11

here's the color image that nicely showed the jet from the artery

44:16

here going to the pseudo aneurysm and the, the, the,

44:19

the sort of in and out doppler in the neck, the yin yang in the do in the neck.

44:24

And it's important to demonstrate the neck, measure the neck.

44:28

If the neck is narrow, then you can really do, um,

44:33

bin injection, which was attempted in this case,

44:40

like a very big scary one.

44:42

So this patient presented with discoloration and large bruise in the,

44:46

in the, in the thigh,

44:48

in the bone extending in the left thigh after a cardiac, uh,

44:53

catheterization. So there's a very large hematoma.

44:57

And even on the gray scale, uh,

44:59

you can see that there is a pseudo aneurysm.

45:02

You can see the movement of the white butt are within the aneurysm.

45:05

And of course we will use color to confirm that's,

45:08

and here's yin yang flow in the neck of the pseudo aneurysm.

45:13

So this is a pseudo aneurysm, uh, surrounded by a very large hematoma.

45:21

Now, just a word about mycotic, aneurysms, complication of endocarditis, sepsis,

45:26

and bacteremia.

45:27

As we saw in our patients or patients who have IV drug use or at much

45:32

higher risk, or if they have, you know, uh,

45:35

septicemia form an abscess somewhere else because of vessel war in

45:40

infected,

45:41

you really need to initially treat with an antibiotic therapy and then

45:46

often have to resect them and prepare them surgically.

45:52

So this is another example of mycotic aneurysm.

45:55

This patient had had a history of I V D U. So again, look at the history.

46:00

If you have the history,

46:01

it's really important 'cause you know what patient is at risk for what, right?

46:04

So if it's an I V D U is at risk for, um,

46:08

just pseudo aneurysm 'cause they inject, but also infected because they,

46:12

they they are at high risk for having endocarditis.

46:15

So we have an eccentric outpouching arising from the artery here, uh,

46:19

with again, a yin yang san. And this again, needed to be treated surgically.

46:24

And the path confirmed that there were gram-positive cox side in the wall of the

46:29

anes.

46:33

So our challenge is really to differentiate pseudo aneurysm and mycotic aneurysm

46:37

from two audio aneurysms. Now,

46:40

true audio aneurysm of focal dilatation of the

46:45

artery, the aneurysm has vessel wall layers as opposed to pseudo aneurysm,

46:49

which is simply a contained break within a vessel.

46:52

Usually you have sfor dation of the artery risk factories atherosclerotic

46:57

disease. And what is important also is that it is a, the,

47:01

the traditional teaching is that if there is a, uh, peripheral aneurysm,

47:05

especially a probably artery aneurysm,

47:07

just look around for other aneurysm especially and including

47:12

aortic abdominal aortic ane because you know,

47:16

obviously if it's an untreated rupture, the patient can die.

47:18

So this is an example of a fusiform

47:23

dilatation of the popal artery with a lot of clot.

47:28

So the lumen is narrowed. Uh,

47:31

and so this is a popal artery aneurysm. And again,

47:35

the traditional teaching is, I, I'm not sure how often I've seen it,

47:38

but if you see a popal artery aneurysm look at the abdominal aorta and make sure

47:43

the patient does not have an abdominal aortic rys.

47:49

Now the next patient is a 54 year old man with palpable white brainin, uh,

47:54

abnormality history, history of IV drug use.

47:58

So here we have yet another, uh, flow pattern.

48:03

So if we look at the left side here, first of all,

48:07

you notice that there is a lot of tissue brewery

48:12

and there is very, very turbulent flow within that vessel.

48:16

This is not normal for an artery, this is not normal for a pain, okay?

48:20

And this was a continuous point. So what are we thinking?

48:24

So we then we look at the vessels around it. So the right side was normal,

48:29

I'm showing it for comparison.

48:31

You have turbulent flow in the left iliac vein,

48:35

and you have in the left iliac artery,

48:38

you have a very abnormal flow for an artery, uh,

48:41

a peripheral artery that is continuous forward for diastole. Okay?

48:44

So what are we thinking?

48:45

We are thinking the patient has a fistula right

48:50

there, an arteriovenous fistula. Okay?

48:54

Remember he was an IV drug user. So again,

48:57

now we look and there's a fistula as well as a pseudo aneurysm. But again,

49:01

this is more of a admixture, ofo and venous flow.

49:05

And when we look at the, the CT here,

49:09

there is contrast in the artery and the vein at the same time again,

49:14

confirming that this is a AV fistula. Okay?

49:18

So what are you going to see in AV fistula? You,

49:20

you're gonna see in mosaic color pattern,

49:22

you ha you're gonna have a color bluey,

49:25

which is the equivalent of the palpable flail.

49:28

You'll have a low resistant turbulent flow. And so in this case,

49:32

I w I was showing you flow in the artery and the vein as well,

49:37

and the right side was normal. Okay? So what happens here is that, again,

49:42

usually at genic, uh,

49:44

you have a track between the artery and the adjacent vein, which,

49:48

which creates a communication between the artery and vein.

49:51

So the vast majority are atrogenic. Uh, you occasionally,

49:55

as the first patient I showed you, could be from, uh, IV drug use.

49:59

And the treatment is more complicated than than pseudo simple pseudo.

50:03

And usually, uh, if it's a big a fistula,

50:07

these patients will need surgical repair.

50:12

Okay? Um, let me, okay, let's go to this case.

50:16

So this is a, um, we're gonna have a little bit of fun here.

50:20

So this is a 37 year old man who has cordal swelling. Uh,

50:25

he was done probably in the I C U and the sonographer call me and say,

50:29

I don't understand what is going on everywhere I look in the testicle,

50:33

I think the testicle has good flow, but I just see I can't find out gel flow.

50:38

I just find this kind of flow. Okay? So this is when, uh, you,

50:42

you wear a detective head,

50:44

I think where the are is a little bit like detective and say, okay,

50:48

this patient was on a coronary unit, right?

50:52

So why does a flow look like that?

50:54

And I would've told you that if you had looked at any of his artery,

50:57

the flow would've looked like that.

50:59

And the reason is that the patient has an L V A D, right?

51:03

And so the sonographer didn't think about it,

51:06

and I've seen this in the carotid I've seen in the femoral artery.

51:09

So unless you, you, you know, you know about it,

51:12

you're gonna be flustered and why can't I find out jail flow?

51:15

But it's simply because a patient has left ventricular assist device. Okay?

51:21

Just another example. In the iliac, uh, uh,

51:25

in all the vessel, this was all, uh, left iliac artery. The right, uh,

51:31

ss f a femoral artery. And that's a typical appearance of, uh,

51:36

high flow,

51:36

low reive waveform with minimal systolic ity or absent systolic

51:42

hospitality because there is a left, uh, ventricle assist device.

51:46

And then I want to have time for questions.

51:49

So I'm just going to show you one more case here. Uh,

51:53

this is another, um, consequence of, you know,

51:57

what the patient has. So this was a femoral artery,

52:02

but we probably do, um, more commonly common, um, you know,

52:07

carotid artery evaluation in patient who are in the coronary care unit because

52:11

maybe they go to surgery and they wanna make sure that their carotid artery are

52:15

patent, they don't have any risk for stroke. In this particular case,

52:18

we're looking at the, at the lower extremity artery.

52:21

But you see this typical dual dual pig flow.

52:26

And these are usually patients who are in a, again,

52:28

in the cardiac unit and they have intraaortic balloon pump.

52:33

And so with intra, uh, uh, aortic balloon pump,

52:37

you have two systolic pigs, right? Because you want to make sure that the,

52:40

the vessels are well perfused.

52:42

So you have the unassisted systole and you have diastolic augmentation

52:47

where the balloon expands so that there is more fluent patient usually who have

52:51

severe heart failure to continue to peruse the brain in particular.

52:55

And then where the balloon deflates,

52:58

you have a little bit of flow at or below baseline. Okay?

53:02

And so with that, uh,

53:04

I want to stop because I wanna make sure we have time for questions.

53:10

All right? Yes. Thank you so much for your lecture today, Dr. Shef. Um,

53:13

at this time we will open the floor for any questions from our audience.

53:17

You may submit a question to Dr. Shef through the q and a feature.

53:23

It

53:24

Looks like we have, someone was asking me,

53:25

is pulmonary embolism less common in MENA syndrome?

53:30

I'm not sure, I'll be very honest with you.

53:32

I'm not sure I have read any statistics, but I would think that the,

53:36

the patient is at risk for p just like with any other D V

53:42

T. Um, it's just that I think, but they are the,

53:46

the main risk for this patient is actually chronic venous insufficiency.

53:51

But I have to say, I haven't read anything that they're less,

53:54

they're gonna be treated with anticoagulation for sure. Uh,

53:57

and they also have going to be treated with, with uh, um,

54:03

uh, thrombolysis and then scan.

54:09

Okay. The other question is,

54:11

what is the difference between hemodynamic significant stenosis for instigator

54:16

stenosis in the peripheral artery? Um,

54:20

well it's basically when we say hemodynamically, significant,

54:25

significant, uh,

54:25

in my mind it's whether the patient needs any kind of intervention or not.

54:31

And so in the peripheral arteries, it's really, um,

54:36

so when we, um, it's really,

54:39

it's very difficult to answer the question because a lot depend on the degree of

54:44

collateral vessels the patient has.

54:47

So yesterday I was reading a C T A where the patient had multiple, uh,

54:53

occlusions. The, they had, uh, uh, stent that were occluded,

54:58

but because they had good peripheral circulation,

55:00

they actually had good flow in the distal bilateral extremities.

55:05

So in the proof in the, in the, in the lower extremity in particular,

55:09

it really depends on the degree of collateral arterial circulation that

55:14

forms. And so I can't say I have a good answer to it.

55:18

I know that in the common carotid artery for on in the, I'm sorry,

55:22

in the internal CID artery,

55:24

we used to say 70% or more is hemodynamic

55:30

significant in that, that this patient may benefit for endarterectomy,

55:34

but I think they're doing less and less and endarterectomy now and managing

55:39

these patients more with medical treatment. So that's the answer I had,

55:44

but it really depends, um, uh,

55:46

particular in the lower extremity about the degree of collateral circulation.

55:53

Okay, the next question is based on the appearance of the thrombus.

55:56

Can we write in the report thrombus is stable or not calcification? Echogenic,

56:01

okay, so, um,

56:03

and I have more experience with the veins here, but if,

56:07

but that's actually true probably for artery. But let me,

56:11

let me talk to vein 'cause that's what I know more about.

56:13

If the vein is expanded, so the diameter of the vein is increased,

56:18

then that's a,

56:19

that's a sign that the thrombus is likely acute and fresh thrombus can

56:24

actually be anti coic. So I think that more,

56:29

a lot of the thrombi we're gonna see now echogenic,

56:31

which makes them easier to recognize.

56:32

But I think to see if something is acute or chronic,

56:35

and we'll first look at the, the diameter of the vein. If the vein is expanded,

56:39

that's a sign that it is more, uh, acute.

56:44

Uh, if there is normal or decreased diameter of the vein,

56:50

if there is just wall thickening and webs,

56:53

so little echogenic lines,

56:55

but but not real bu then I think you can say that at least its subacute acute.

57:01

And if there are calcifications in a vein where the wall is thickened,

57:05

then it's much more likely to be chronic. And now we don't say so. I think, um,

57:10

Dr. Needleman who is Jefferson and is really an expert on venous ultrasound,

57:15

he likes to say if you see sequela from a previous D V T,

57:19

he doesn't like us to say it's chronic D V T,

57:21

he likes to say it's post-thrombotic changes. And in this case,

57:25

usually the vein will be small. You have thickened wall,

57:30

you may have echogenic webs,

57:31

and sometimes you will see collateral veins as well around the area.

57:35

So if you see a lot of collateral veins around an area,

57:38

that's also an indication that this may be at least subacute or chronic.

57:47

Can I explain the concept of, uh, systolic pic again? Okay,

57:51

so it's, it's, it's here. Okay, let's see. Uh,

57:57

let me see if I can move this. Can you guys see my screen?

58:03

Yes. Okay. So basically what happens, okay,

58:06

when you have an intraaortic balloon pump, okay, the,

58:11

you want to give as much 'cause the heart cannot pump. I mean the,

58:14

the patient usually have marked, uh,

58:17

decreased e ejection fraction. And I'm not a cardiologist, so I'm not sure I,

58:22

I get the physiology right.

58:23

But what happened is that you have the initial systolic peak with the, the, the,

58:27

the, the, the normal peak of the aorta.

58:29

And then there is the assisted systole with, in, with,

58:33

in diastole the balloon expense to kind of try to move more,

58:39

more blood forward in patients with low ejection fracture.

58:44

This is why you have the second systolic peak.

58:46

This one is reflects diastolic augmentation when the balloon expands

58:51

to push more blood forward.

58:57

How do we assess deep venous insufficiency? Um, so,

59:03

um, I don't do this routinely. So what,

59:08

what you look for,

59:08

you look for with reverse solar flow and venous and, and you know,

59:13

flow going in the wrong direction in a vein,

59:17

but I'm sorry I don't do this routinely,

59:19

so I cannot answer any better. I apologize for that.

59:26

Um, if peripheral arteries or biophysical monophasic flow,

59:33

should we write peripheral artery disease in the ultrasound report? Okay,

59:37

so biphasic is at least

59:42

if you have some flow below baseline, okay?

59:45

If you have a sharp systolic up stroke and some flow below baseline,

59:50

I think that's okay because sometimes the phasic, the third pig is very,

59:54

very small and you can't see it if you have monophasic flow, yes,

59:58

you have to suspect that, uh, on, uh, on that,

60:03

that there is something, something else going on.

60:06

And we are concerned about peripheral arter disease, yes,

60:09

if there is monophasic flow,

60:11

and if you have tardis pers that's even more of an indication that there is an

60:15

uh, uh, either an occlusion or stenosis more centrally.

60:27

Okay? I didn't really address vari cil and nut Quaker syndrome,

60:31

so I'm gonna skip this one. Uh, and,

60:38

and so let me look the, the last two questions.

60:40

So please report the concept of mono physical chill flow. Okay? So, so,

60:46

so that really depends where you are. So in the,

60:51

we we're talking about peripheral arterial system.

60:53

So in the peripheral arteries in the arms or the legs,

60:57

because we supply, they supply muscles, which is a high resistance bed.

61:02

You should have a sharp systolic up stroke, you should have reversal flow,

61:06

transient reversal flu in diastole.

61:10

If you have a more central stenosis,

61:14

the theory is the flow will become very turbulent and there may be some

61:18

vasodilator and other, uh, chemical, uh,

61:24

phenomenon at work at at at work,

61:27

which will say that the flow becomes,

61:29

you have a parvis tous where you have a, uh,

61:34

lack of sharp systolic up stroke, you have a more slopey, uh,

61:37

initial systole and then you have turbulent flow because of the stenosis of the

61:42

occlusion. And so you have a lot of turbulent flow,

61:45

you have more flow in diastole. That's the best explanation I can give you.

61:54

Um, okay, two more. So if there is positive flow in e femoral vein,

61:58

does it indicate? So, um, okay,

62:02

so when you look at this positive flow in the femoral vein,

62:05

so you should have some positivity.

62:08

Now sometimes you have a lot of positivity because a patient's in cardiac

62:11

failure. And so again,

62:14

what I always do is look at the other side.

62:17

If both sides look the same and there's increased positivity possible,

62:21

the patient has cardiac failure, and sometimes you'll see this, right,

62:25

because patients came with low extremity edema, usually bilateral,

62:29

and you know the questions that D V T or is that heart failure?

62:32

If it's unilateral, then I worry.

62:36

And one of the thing that it can be if it's unilateral and there is

62:41

increased possibility as opposed to decreased possibility that I showed you

62:46

is that you may, you may be dealing with an auto venous fistula. Um,

62:50

you have to look at the artery.

62:51

There are other signs to look at if the patient has a risk factor,

62:54

does the patient have a recent procedure, et cetera. Okay.

63:01

So, um, it's past one o'clock, so I think I'm gonna stop.

63:04

I really thank you very much for, uh,

63:07

attending and I thank you for the excellent questions. Uh,

63:11

I hope I was able to answer most of them at your satisfaction.

63:13

Thank you very much,

63:16

Dr. She thank you so much for your lecture today.

63:18

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63:21

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63:34

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