0:00

Moving along to targeting using tomosynthesis.

0:04

This is, um, how we identify Z by the number

0:07

of one millimeter slices between the reference

0:11

and the target here is our patient donate prone stereotactic

0:16

table, and Z is the number of one millimeter slices

0:20

between the reference and the target.

0:22

Again, the reference can be at the paddle here at the

0:26

surface of the breast where the opening is

0:29

or at the detector depending upon the manufacturer.

0:34

An example of a patient who had a new group

0:37

of calcifications in the left breast, um,

0:41

showing you these, this group of three,

0:44

not particularly suspicious morphologically,

0:47

but definitely new and therefore needed to be biopsied.

0:51

We chose to target these from an inferior approach,

0:57

so a CC from below

1:00

and we obtain a tomosynthesis uh, series.

1:04

This is a single slice of the tomosynthesis series showing

1:08

that the calcifications came into focus at

1:13

35 millimeters from the detector,

1:17

which is one, this is the head.

1:19

Remember, we're coming CC from below.

1:21

So this is the head and the paddles at the feet.

1:25

So we've determined Z just by the distance

1:28

from the reference point.

1:32

Another example of calcifications seen on a screening

1:36

mammogram in a patient who has a history of reduction,

1:38

mammoplasty, just photographic mags of these calcifications.

1:44

These were recalled, uh,

1:46

because they looked course heterogeneous and they were new,

1:49

although it does look like there is some lucency associated

1:52

with these calcifications suggesting the possibility

1:55

of fat necrosis diagnostic evaluation was

1:59

performed with magnification views and an ML V.

2:05

And, uh, the radiologist on that day wanted to pursue biopsy

2:10

despite the fact that these had a likelihood

2:12

of being benign fat necrosis.

2:16

The calcifications are located at 12

2:19

o'clock at a middle depth.

2:21

A superior approach was chosen for targeting.

2:26

So again, the patient is placed, uh, in a CC projection

2:32

with the first slice being at the foot

2:35

and the last slice, uh, being at the surface

2:38

of the breast towards her head.

2:40

And here is the slice

2:42

where the calcifications come into focus.

2:46

So we're able to determine our, uh, z depth.

2:50

Basically on our first scout series

2:54

after lidocaine was placed, uh,

2:56

we did a repeat tomosynthesis

2:58

Series and we like to do this

3:00

because the calcifications can be displaced by the volume

3:04

of local anesthetic.

3:08

On a pre-fire image.

3:09

The needle is pointing directly at the calcifications.

3:13

Uh, and you can see the calcifications are in focus on this

3:16

slice right where the needle tip is.

3:20

And we opted not to get a post, uh, fire image

3:23

because with tomosynthesis the needle can obscure the

3:26

underlying target Specimen radiographs shows calcifications

3:31

in several cores.

3:32

Here's some calcifications here and up here.

3:35

And, uh, the diagnosis was fat necrosis.

3:39

This was biopsied last week,

3:40

but the results came back rather quickly.

3:45

A clip was placed. Notice

3:46

that these are stereotactic images obtained.

3:50

The reason we do this at our institution is

3:53

because we do not have a code

3:56

for tomosynthesis biopsy.

3:58

All of them are scheduled as stereotactic biopsies,

4:02

but most of them are now done with tomosynthesis.

4:05

Because we are charging for a stereotactic biopsy,

4:09

we do need to obtain a stereotactic

4:11

pair sometime during the biopsy.

4:14

And most of the time we choose to do this at the end

4:17

after clip placement.

4:18

So here's the clip and clip

4:20

and residual calcifications post biopsy.

4:23

Mammogram should always be performed

4:25

and compared to the, uh, diagnostic and screening images.

4:29

So CC views on the left.

4:32

Here's the prebi post biopsy showing the clip adjacent

4:36

to the calcifications prebi ML V

4:41

post biopsy ML V again showing the clip adjacent

4:44

to the calcifications on both views.

4:49

A few words about the importance

4:51

of the post biopsy mammogram in the situation, uh,

4:54

we just looked at there were residual calcifications,

4:58

so if the clip were displaced, um,

5:00

that wouldn't necessarily be a problem

5:02

because we could still, if necessary,

5:05

use a residual calcifications

5:07

for targeting for localization.

5:11

If there were not a residual target

5:14

and the clip were displaced, it may be challenging

5:17

to localize the biopsy cavity.

5:19

And this should be known in advance.

5:22

Sometimes additional imaging needs to be performed

5:24

to find the original biopsy site if it's

5:27

cancer such as an MR.

5:28

I also important

5:31

to consider on the post biopsy mammogram is whether

5:33

or not you biopsy the right thing.

5:35

Sometimes patients have multiple groups of calcifications

5:39

and on the biopsy table it can be a little bit confusing.

5:43

And so it's always important to look at the placement

5:46

of the clip following biopsy to confirm

5:48

that the correct group has been biopsied.