0:00

Okay, here's an interesting case

0:01

of an 83-year-old with a PSA of 7.8,

0:05

13 days before this study.

0:10

But the PSA density, which is the PSA

0:13

divided by the gland volume, is 0.21 nanograms

0:18

per mL per cc.

0:20

So, the PSA density is slightly above the Rubicon,

0:24

in other words, it's higher than the point

0:28

0.2 cutoff that makes you more suspicious

0:32

and gives you greater likelihood of

0:34

having a cancer inside the gland.

0:36

So, in certain circumstances, we may

0:39

use that to push us one way or another.

0:42

Just like we might use a series of negative

0:44

biopsies to push us one way or another.

0:47

Or a very stable PSA over

0:49

a long period of time, etc.

0:51

So we have in the upper left-hand

0:53

corner an axial T2, 2D

0:56

fast spin-echo, patient's been properly prepped,

0:59

there's only fluid and feces, no air to destroy

1:04

our diffusion image, which happens a lot; want

1:06

to make sure the air is out of the rectum.

1:09

We have a diffusion-weighted high B-value

1:12

image on the right, upper right, the

1:15

ADC map on the lower left, and our DCE,

1:19

dynamic contrast-enhanced, gadolinium

1:21

augmented MR in the lower right-hand corner.

1:25

So let's start out

1:27

with the T2.

1:30

You know, I find it easiest to look

1:32

at the ADC map first because kind of

1:35

that's where the hot spots are.

1:37

It's kind of like looking at the STIR (Short Tau Inversion Recovery)

1:38

image in, in musculoskeletal MRI (Magnetic Resonance Imaging).

1:41

You know, it's a little easier to

1:42

see white on dark than it is to

1:45

see dark on dark or dark on white.

1:48

So right away we see this dot in

1:51

the, on the left side of the gland.

1:53

And it's down low near the apex in the

1:55

peripheral zone, and it corresponds not just to

1:58

a lesion but to a lesion that's. Now, we like

2:03

to see a nodule, but even worse, a nodule with

2:07

speculation, kind of like a breast cancer.

2:09

That's even worse.

2:10

And this thing has some

2:11

speculation associated with it.

2:14

It's not very big, but it's, it's darn bright.

2:18

Look at it on the ADC map.

2:21

It's darn dark.

2:22

I'm going to blow it up even a little bigger.

2:25

Look how black it is.

2:26

So it's telling you there's really profound

2:29

diffusion restriction of this lesion.

2:31

It's less than 15 millimeters, so it

2:34

meets PI-RADS criteria for a PI-RADS 4.

2:41

Now we're not done yet.

2:43

Let's go down all the way to the

2:45

urethra, and now let's work our way back

2:48

approximately, and we run into something else.

2:53

Now maybe these are connected, maybe not.

2:55

You know, here's a lesion,

2:57

That's still part of the lesion.

2:58

Maybe that's connected, but

3:01

let's assume it's not connected.

3:04

This lesion is abutting the anatomic capsule.

3:08

It's definitely asymmetric from the other side,

3:11

and it has a faced the surgical pseudo-capsule.

3:16

Now, I've said in the past, in other vignettes

3:18

that you can get extrusion of TZ material

3:21

out, so that extrusion is almost always in

3:26

the form of an encapsulated gray nodule.

3:30

In other words, it's well-circumscribed or.

3:33

It's extruded in the form, we'll use blue

3:36

for water, in the form of a very white

3:39

nodule and sometimes multiple white nodules.

3:42

So they're round, they're homogeneous, they

3:46

may be multiple, but that isn't the case here.

3:49

This one's more of a wax on, wax off.

3:52

It's ill-defined, it doesn't have edges to it.

3:56

Let's go over to the diffusion image.

4:00

It diffusion restricts, but not

4:03

as much as our other lesion.

4:05

There's less diffusion restriction.

4:08

There is less low signal

4:11

intensity on the parametric map.

4:15

So, this one, you might downgrade a little bit.

4:20

You might, if it had been sitting there all

4:22

by itself, you might call it a PI-RADS 3.

4:27

So, what's a mother to do?

4:29

You might look at your DCE MRI (Dynamic contrast-enhanced magnetic resonance imaging).

4:32

Let's do that.

4:33

Let's go to the original lesion that

4:36

we were confident was a PI-RADS 4.

4:40

Lots of diffusion restriction.

4:43

Lots of low signal on the parametric map.

4:47

Hypervascular.

4:49

Now let's go to our other lesion.

4:51

The one that's closer to the mid gland.

4:55

It's hypervascular.

4:56

In fact, it's even more hypervascular,

4:59

although slightly so, than the lesion

5:02

that diffusion restricts more avidly.

5:05

So, this one is in the mid gland, PZP.

5:10

If you gave it a PI-RADS 3 because of its weak

5:14

diffusivity or diffusion characteristics, then

5:17

you might give it a 3 plus 1 because of the

5:20

hypervascularity making it another PI-RADS 4.

5:25

So this is an example of a pure lower down in the

5:29

apex PI-RADS 4, and up in the mid gland, more in

5:34

the back, a PI-RADS 4 because we have a PI-RADS

5:38

3 by strict criteria and then adding as a bumper

5:42

for The DCE MRI is a 1, so 3 plus 1 equals 4.

5:47

Remember though, when you are looking at these two

5:49

types of lesions, the true PI-RADS 4s tend to have

5:54

a higher Gleason value than the 3 plus 1 equals 4.

5:59

And we'll stop right there.