0:00

This is a 75-year-old with a PSA of 6, no urinary

0:04

symptoms, and a benign palpating gland on exam.

0:08

We have our axial T2,our axial ADC map, windowed at 1400x1400,

0:13

a B equals 1600 diffusion image,

0:16

and sort of a mid-phase post-contrast image.

0:20

Um, so when I scroll through this case,

0:23

on the ADC map and look in the peripheral

0:25

zone, I don't see any focal black holes.

0:28

There's no areas to me of focal diffusion

0:30

restriction sitting in the peripheral zone.

0:34

When I look in the transition zone, I see a moderately

0:36

enlarged transition zone with some nodular findings.

0:42

I see some thickened stroma anteriorly,

0:45

normal region of the central gland.

0:50

This patient had a PSA density of. And I believe when

0:55

we read this study initially many years ago, we found

0:58

something over on the left side to do a targeted biopsy

1:01

on that in retrospect doesn't meet the PI-RADS criteria.

1:04

Systematic biopsies in this patient showed a

1:06

significant neoplasm at the right base laterally,

1:10

which should be somewhere up in this region.

1:12

So certainly in the peripheral

1:13

zone, I don't see a correlate.

1:15

Um, the only thing that I'm seeing in

1:17

retrospect that might correspond to this.

1:20

Is this region right here.

1:21

And I would have thought this was

1:23

low signal in part of a BPH nodule.

1:26

Um, it has nicely defined margins.

1:28

They're irregular, but they're well-defined.

1:30

It's nice low signal.

1:31

There's no diffusion restriction.

1:33

It doesn't have a lenticular shape.

1:35

Even in retrospect, this to me looks

1:37

like low signal within a BPH nodule.

1:39

Um, so, even probably today I

1:42

would have read this as low signal.

1:44

No evidence of a focal neoplasm.

1:47

So, in our practice, patients

1:49

who have a PSA density above 0.15

1:51

proceed to biopsy, even if

1:55

they don't have a focal lesion.

1:56

And the reason for that is that, you know,

1:58

sometimes MR doesn't see the significant cancers.

2:02

And in patients with a Um, and, and you can use

2:07

different levels of PSA density as a risk threshold

2:10

to decide which patients with a normal MRI to biopsy

2:13

and which patients with a normal MRI not to biopsy.

2:16

And different groups use different risk thresholds

2:19

and we've been happy, uh, with a threshold of 0.15.

2:22

52 00:02:22,724 --> 00:02:24,890 And of course, there's always a discussion between, you,

2:24

the radiologist, and the patient as to whether or not they should

2:27

go to biopsy or if that threshold should be a little higher,

2:29

a little lower, and that can take into account things like

2:32

family history, personal preference, and, and so forth.

2:35

Uh, and it's important because no test is perfect, and

2:38

the MR is going to not show the findings sometimes.

2:41

Uh, so having another parameter that you can use to push

2:44

higher-risk patients towards biopsy, even in the absence

2:47

of a finding in MRI, is very good and we found that this

2:51

is not significantly increasing the number of men that we

2:53

biopsy but we do find cancer occasionally in these patients.

2:59

And then even if, you know, the MR didn't show

3:01

anything and the biopsy comes back positive it's

3:04

not a waste because you can go back and oftentimes

3:07

you'll see on the MR what What the biopsy corresponds

3:10

to, even if you didn't call it prospectively.

3:12

So even in this case, if this was the region

3:15

where the biopsy came positive from, I can still

3:18

estimate a size, which is helpful in treatment.

3:21

I can still say, Hey, there's no extracapsular spread.

3:23

Uh, so the scan can still be useful in retrospect.

3:26

And sometimes you'll find it's

3:27

not that the scan didn't show it.

3:29

It's that we just missed it and

3:31

didn't see it and misread the scan.

3:33

And in that case, it becomes a

3:34

very good learning experience.