0:00

At all times during the procedure, you want to make sure

0:03

that you are seeing your entire needle.

0:06

Um, when I'm working with trainees, I'm usually standing

0:08

behind the shoulder saying, show me the needle.

0:11

Show me the needle as often as I need to,

0:14

because I never really know where that needle tip is

0:17

with them unless I'm seeing the entire

0:19

length of that needle.

0:21

So here's some general guidelines, uh,

0:24

that I teach to our residents.

0:26

Only move one hand at a time.

0:27

You either move your transducer hand

0:30

or you move the needle, not both at the same time

0:33

and move each of them very slowly.

0:36

Glac slowly, like YouTube on 0.5 speed.

0:40

Slowly, I find that residents move way too fast

0:44

and they actually whiz past the needle without

0:47

ever really seeing it.

0:48

And then they're doing a lot of hunting

0:50

around on the screen.

0:51

Look at your hands as much as you look at the screen.

0:55

Um, many times the reason that you can't see the needle is

0:59

because you are completely off angle with it.

1:01

And if you look down at your hands,

1:02

you would see you're not in the center of the transducer.

1:05

That needle must be parallel to,

1:08

and it must be in the center of the transducer for you

1:11

to both see it and know directly where it's going to.

1:15

You need to see the total length of the needle

1:18

to predict direction.

1:19

I'm gonna show you some examples in a moment.

1:22

Now remember that these, um, high

1:25

resolution linear transducers have a very narrow focal zone,

1:30

which you have, um, hopefully centered your focal zone

1:33

directly at the lesion here.

1:35

This is really pretty narrow

1:36

and you've gotta have your needle within this focal

1:39

zone to be able to see it.

1:41

If you're not seeing the entire length of the needle,

1:44

but you're only seeing part of it like this,

1:46

you don't really know what direction that needle's going in.

1:49

And you may think that this is perfectly fine,

1:51

that you're right in the middle of the lesion,

1:54

but when you deploy this needle, you're gonna be on the edge

1:57

of the lesion like here.

1:59

So you must look at your hands

2:00

and make sure that you are parallel to that transducer

2:03

and you're right in the center.

2:06

So you really need to be looking at your hands.

2:08

It needs to be like this.

2:11

You'll needle directly in the center of

2:14

that transducer directly parallel to it

2:16

because a lot of the time I see with trainees

2:20

that this is the situation

2:22

and if they just look at their hands, they'll be able

2:24

to correct that one more time.

2:26

This is what it needs to be looking like.

2:28

You have to be parallel,

2:31

not non-parallel if you're looking from above.

2:35

And what I'm showing you here on these images are the effect

2:38

of not seeing the whole of the needle.

2:40

So I have not moved the needle, uh,

2:42

between these two images.

2:44

All I've done is move the transducer just rotated

2:47

a little bit here.

2:48

It looked like here was the apparent tip of the needle

2:53

where actually the needle is much deeper.

2:56

It's all the way down here.

2:57

And uh, this little video clip at the bottom here is just

3:00

showing me rotating the transducer to show you

3:03

how you can really falsely think

3:05

that the tip is in a different place than the other.

3:08

It's, uh, not that uncommon.

3:10

I found the needle tip

3:11

of a resident is actually wan near the chest wall when they

3:13

thought it was much more superficial.

3:17

One of the challenges I frequently find

3:19

that trainees have when doing breast biopsies is trying

3:23

to make sure that that, uh, needle is centered on the lesion

3:27

and they're not doing biopsies off to one side or another.

3:31

So you want to have most biopsies

3:33

through the center of the lesion.

3:34

Um, is okay to have one

3:36

or two more peripheral, uh,

3:38

biopsies sometimes actually helps a pathologist

3:40

to see an edge between normal tissue and the lesion.

3:43

You want to avoid necrotic areas, um,

3:46

they're not gonna be helpful biopsies.

3:48

And to do this, you need to make sure

3:50

that you always have your needle within the focal

3:52

zone of the transducer.

3:54

I'm gonna show you a couple of quick tricks,

3:56

which I find are very helpful.

3:58

If you're finding your peripheral rather

3:59

than central on a lesion.

4:01

First of all, you need to work out which side

4:04

of the lesion the needle is.

4:05

Is it closer to you than the lesion

4:08

or is the needle on the other side of the lesion?

4:11

Um, so do need to think about that for a little bit.

4:14

Just scan back and forth until you work that out.

4:17

The first and the most easy thing you can do is just

4:20

translate your needle.

4:21

So just either push it away

4:24

if the lesion is on the other side of it

4:26

or pull it towards you if the lesion is closer

4:29

to you than the needle.

4:31

And that works quite a lot of the time.

4:34

But unfortunately, sometimes,

4:35

particularly in denser breasts, um, as you push a needle,

4:39

the lesion pushes away as well.

4:41

And in these cases, I have a different way to deal with it.

4:46

If you have problems with translating on a lesion, um,

4:50

as I showed you before, then you can try rotating.

4:53

So the direction that you rotate

4:55

and you rotate the transducer

4:58

and the needle as a unit

5:00

with the lesion being kind of the fulcrum, the central part

5:04

of this, I'm gonna demonstrate this in just a minute, um,

5:07

which way you turn it will depend on whether your needle is

5:10

on the other side of the lesion or it's towards you.

5:13

So here we're demonstrating it with the needle

5:16

and the transducer being on the far side of the lesion.

5:20

And you'll see here I rotate anticlockwise.

5:23

And you can see here that now

5:24

that needle is nicely pointing

5:26

towards the center of the unit.

5:28

Now on the next slide, I'm gonna show you

5:30

what happens if you start with a needle closer to you

5:33

and the lesion further away.

5:36

So here we have the needle on the transducer

5:40

on the near side of the lesion.

5:42

Then we're just gonna rotate it clockwise.

5:45

If you have a smaller lesion, then you may want

5:49

to use perpendicular imaging to be able

5:51

to check the adequacy of your sampling.

5:55

So generally speaking, we're

5:56

Going to be imaging in a longitudinal plane, so parallel

6:00

to the needle and lesion,

6:02

but you can change your orientation so you are perpendicular

6:06

to the needle to make sure that biopsy is within the lesion.

6:09

Don't forget, there's a little bit of partial volume effect

6:12

and you may think you're within a lesion longitudinally.

6:15

Um, only really applies to smaller lesions,

6:17

but when you turn perpendicular, you may not be.

6:20

And I'm just gonna demonstrate that in the next two slides.

6:24

So here I'm just using my friend the pork loin

6:27

with some olives in it to demonstrate this.

6:30

So in this first diagram here we see here's our needle

6:35

tip prior to it being deployed,

6:37

here's our olive L lesion.

6:41

Here's longitudinal.

6:42

After we've deployed it, it looks nicely through it.

6:45

And then I'm turning my probe. So it's perpendicular.

6:49

You often have to follow that needle down kind of

6:51

from the side

6:53

of the skin just going down towards the lesion,

6:55

just following it all the way.

6:56

And you can see here that the tip

6:58

of my needle is nicely within the olive.

7:01

By contrast, in this patient, it looks pre-fire,

7:04

like I'm sort of nicely directed towards my

7:06

lesion post-fire.

7:08

You could might think that you are within the lesion

7:11

as you're seeing them both in the same image,

7:13

but when you turn perpendicular on it,

7:15

the needle tip is actually on the periphery.

7:19

And in fact, probably outside of the lesion.