0:00

This is a case of a 75-year-old man with a PSA of 7 and a

0:05

benign gland on physical exam and no urinary symptoms.

0:09

So we go to the images and we have axial T2 images,

0:13

an axial ADC map windowed at 1400 by 1400, an axial

0:19

interpolated high B-value image with B of 1600.

0:23

In this case, I have a delayed post-contrast image.

0:26

It's not the arterial phase.

0:28

Uh, and I will explain why I'm showing that a bit later.

0:31

Uh, so we start with this case, we start looking

0:33

at the peripheral zone, and even though, you

0:36

know, the most information in the peripheral

0:38

zone is on the diffusion images, I still, as a

0:40

creature of habit, start looking at the T2 images.

0:44

So, sort of up near the base of the gland, it's got a

0:47

little bit of a heterogeneous appearance, you know, high.

0:50

Now this here, if you corroborate on the coronal

0:53

images, you'll see this is Central zone tissue,

0:56

so I'm not going to worry about that right now.

0:59

Peripheral zone, peripheral zone, what catches

1:01

my eye here is, there's kind of this poorly

1:03

defined wedge-shaped area of low T2 signal.

1:06

That extends all the way out,

1:08

uh, to the capsule of the gland.

1:11

And this is one example where I look at, and

1:13

I think this is going to be prostatitis.

1:17

Then I look at the diffusion images,

1:19

there's actually very low, uh, signal here.

1:22

Kind of a black hole on these windows.

1:24

And when I draw an ROI, measure what the ADC value is.

1:28

It's below 900.

1:34

And then when I look on the high

1:35

B-value images, it's bright.

1:37

So this meets criteria based on the

1:39

diffusion images for a PI-RADS 4 lesion.

1:42

Because we measure it, it measures less than 1.

1:44

5 centimeters.

1:45

If it were greater than 1.

1:46

5 centimeters, it'd be a PI-RADS 5 lesion, right?

1:49

Okay, uh, so this is one of those where based on the

1:52

diffusion you have to call it PI-RADS 4 and it's

1:55

going to get biopsied and this was biopsied and uh, 2

1:58

out of 2 cores came back with Gleason 4 plus 3 disease.

2:01

Uh, so you're not always happy calling

2:04

these but you got to follow the rules.

2:06

In one of the previous cases, Uh, we didn't get high

2:08

grade cancer, and that's because not all PI-RADS 4

2:11

lesions are going to be high grade cancer, but enough

2:15

of them are that you need to biopsy them, right?

2:18

Right.

2:18

So if we look at the rest of the peripheral zone on

2:20

the ADC map, uh, it's relatively high signal.

2:24

There are no more focal areas of well

2:26

defined low, low signal on the ADC map.

2:29

So that's the only lesion in the peripheral zone.

2:32

You go to the transition zone and it has this typical normal

2:35

nodular appearance that you see with prostatic hypertrophy.

2:40

Okay, and then we look at the anterior stroma, and

2:44

this is an area that's the learning point on this case,

2:47

and you're going to find that you end up biopsying

2:49

a lot of anterior stroma before you really become

2:53

comfortable saying what is anterior stroma, and

2:55

what's an anterior transition zone suspicious finding.

3:01

probably two and a half, three centimeters in diameter.

3:03

It's crescentric, it insinuates,

3:06

between nodules in the gland.

3:09

It's got some low signal on the ADC map here

3:12

with an ADC value of 870, so well below 1000.

3:17

In this case, it's not terribly high signal on the

3:21

high B-value image, but remember in the transition

3:24

zone it's the T2 that matters and these images don't

3:27

really, aren't supposed to sway you all that much.

3:30

Uh, so this was, uh, called a suspicious PI-RADS 5 lesion,

3:33

it was biopsied, it came back normal fibromuscular tissue.

3:37

But as you get more experienced with anterior stroma, and

3:40

you look at this, this looks like typical anterior stroma.

3:43

It's located on the anterior part of the gland.

3:45

Right?

3:46

It tapers very narrowly on the edges.

3:49

It insinuates between the nodules from the

3:52

anterior side, but not so much laterally.

3:55

Uh, it may have restricted diffusion.

3:57

It's fibrous tissue, so diffusion is going to be restricted.

4:00

But the key to me that this tissue

4:02

is anterior stroma is that there's almost no

4:05

enhancement either on the early or the late images.

4:09

Uh, and when you see this enough and you've

4:11

biopsied enough, you become confident that

4:12

this is what anterior stroma looks like.