0:00

This is a case of a 69-year-old with

0:03

a PSA of 7 and no urinary symptoms.

0:06

We have our axial T2, axial

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ADC map, and axial high B value.

0:11

It's a 1600 interpolated image

0:14

and an early arterial phase image.

0:17

And we'll start by just noticing that the ADC map

0:20

and the high B value image are pretty low quality.

0:24

And I know when I see a case that's got low quality

0:27

ADC map and high B value that it's going to be hard.

0:31

And I may not do as good a job as I

0:34

normally would because those are the

0:35

key sequences in the peripheral zone.

0:38

And when they don't look really

0:39

nice, your confidence goes down.

0:41

So if you feel the same way, you

0:44

know, you got good company here.

0:46

So we'll start in the peripheral zone.

0:47

So in the T2 images, the peripheral zone is a

0:50

little heterogeneous, got some streaky areas.

0:53

Uh, but I don't see a mass that I

0:55

feel like I could pluck off the page.

0:57

Maybe there's a little bit of

0:58

decreased signal down in this region.

1:00

We'll look over on the ADC map, and corresponding

1:02

to this area here, there is a focal black hole,

1:06

um, on the ADC map, and it's not letting me draw

1:10

a circle and show you, uh, what the ADC value was.

1:13

If we look kind of back in the report

1:15

for this, the ADC value was 700, right?

1:20

1000 threshold that I like to use.

1:21

It makes you worry about something

1:23

being a PI-RADS 4 or 5 lesion.

1:26

Given its size, less than a

1:28

centimeter, it's going to be a 4.

1:29

The problem is it's not bright

1:31

on the high B value image.

1:35

Maybe it's a little bright, but it's not.

1:38

Is there a focal contrast enhancement?

1:40

I don't think you can say that there is.

1:42

Um, and then, is there even

1:44

something there on the T2 image?

1:45

Well, towards the apex, sometimes the axial

1:47

images cannot be as sensitive because the gland

1:51

curves around and you're kind of imaging in plane.

1:54

If you look on a coronal image, in

1:56

this region, so let's scroll back.

1:59

Now there is some abnormal T2 signal in the area.

2:03

It's a bit wedge-shaped, um, on T2, but

2:07

it looks focal on the ADC map.

2:10

So, if we were going strictly by PIRADS,

2:13

this should be called a PIRADS 3 lesion.

2:15

There's a well-defined area of diffusion

2:17

restriction on the ADC map that's not

2:20

corroborated on the high B value images,

2:24

and there's no enhancement, so it's a, no

2:27

focal enhancement, so it's a PI-RADS 3.

2:30

Um, This case I think was read before we were

2:34

using PIRADS, so this lesion was biopsied.

2:37

This came back as a Gleason 3

2:39

plus 3 or Gleason 6 disease.

2:42

And even if you thought there was some enhancement

2:44

here and upgraded to a 4, it would still have come

2:48

back as a Gleason 6 disease, Gleason 6 neoplasm.

2:52

So the thing to remember is that the role of

2:55

MR, right, is to reduce the number of men who

2:58

are getting a biopsy, not eliminate, and also to

3:00

help correlate, you know, the size and location

3:03

of a cancer with what you get on the biopsy.

3:05

All right, so not everything you call PIRADS4 is

3:08

going to be a significant neoplasm, and that's okay.

3:12

In fact, hopefully you'll miss a lot of PIRADS,

3:14

sorry, you'll miss a lot of Gleason 6s, because

3:16

we don't always even want to see those, and

3:19

hopefully that the number of Gleason 6s that

3:21

you biopsy from PI-RADS 4 lesions will be small.

3:25

So, here's an example of where the diffusion

3:27

really makes you call this at least a, a PI-RADS 3.

3:32

Um, I've been fooled a lot of times by the

3:35

starkness of the black hole on the ADC map

3:38

and not seeing anything on the high B value.

3:41

And I've caught a lot of those 4s

3:43

when I should have called them 3s.

3:45

And almost all of those, even if they

3:46

come back as Gleason 6s, or as nothing.

3:49

So even after, you know, 20 years of doing this,

3:52

you still sometimes find yourself struggling

3:54

a little bit on these hard ones, and it always

3:56

seems to be in the cases where the ADC map and

3:59

the high B value images are pretty low quality.

4:02

So moving on from the peripheral

4:04

zone, we have the transition zone.

4:06

The transition zone is heterogeneous, it's

4:09

low signal, there's nothing lenticular.

4:11

There's nothing pushing things out of the way.

4:14

Um, this is a nice example of some anterior stroma.

4:18

So again, right, it's chrysentric.

4:20

It's not lenticular.

4:22

It's not pushing this.

4:23

It's not, you know, going like this.

4:24

Flattening the anterior transition zone.

4:26

It does show low signal on the ADC map.

4:29

It doesn't show high signal on the high B value.

4:32

But again, the quality is not that good.

4:34

But most importantly, it shows no enhancement.

4:37

Alright, so this is spanning the entire anterior

4:40

aspect of the transition zone like the stroma does.

4:43

There's no enhancement early.

4:44

If I showed you the delayed images,

4:46

there'd be no enhancement late.

4:47

Uh, this is a nice example of anterior stroma.