PI-RADS Assessment

Introduction to PI-RADS Version 2 Availability

I'm Jeff Weinreb,
and I'm gonna be talking about
higher Ed's assessment in this talk.
A lot of people have been asking,
it's nice
that we're talking about PI Rads,
but version two,
but when is it going to be available
so you can actually use it?
And what I want to tell you is that there's
a number of different parts of the document
that will become available.
So,
there's a section in it on clinical,
and I'll tell you where we are with it
and when you'll be able to have access to it.
There's a part of the document on clinical considerations
and technical specifications,
which goes into discussion about three point
three T versus 1.5 T
and the rectal coil not on the recal coil,
and a whole bunch of other issues with patient preparation
and things like that that you've heard about.
So that's pretty much done.
There's a section in it about
just the normal prostate including the anatomy
as well as common benign findings.
There's a section in there about the assessment,
so not just the tables,
but actually sort of a very explicit directions about
how to use the, how to do the assessment.
And there's a section in there on staging.
Staging is not emphasized
because there's probably better resources for that.
And there's nothing really original in the document about
staging, but there is a section in there about staging.
So all of those things will, we hope be available prior
to the, sometime prior to the RSNA
and it'll be posted on the a CR website
because they've supported this development.

Appendices and Supporting Resources

There's also a number of appendices
that we've been developing to compliment the
written document.
And amongst these are report templates.
So we'd like for reports to be more
or less standardized along the lines of
what the pathologists have done.
If any of you have looked at the reports from pathologists nowadays, they're very,
very standardized and this would be very, very useful.
So we're gonna have report templates in there, one of them
with for people who use free text,
and another one in there for those of you who might want
to use a structured report, we're still working on those.
Those should be ready shortly.
There's a section in there
with the sector map explaining what it is
that's already done.
You already saw it, except it's got nicer colors in it than
we were able to display here for some reason.
There's the lexicon, which is more or less completed,
and you already heard about that.
There are gonna be sample protocols.
So what we've done is we've asked all of the members
of the steering committee to submit protocols,
a standard protocol for the scanner that they're using
and the coil that they're using.
And that should be available hopefully,
I don't know if it'll be available prior to RSNA,
but if not, it'll be available soon after that.
So you can, depending upon what scanner you have,
you can go there and see what you're using
or at least just compare what you're doing to what
the experts
who are on the steering committee are doing.
And then finally, there's an atlas,
and the atlas is under development.
And the idea here is we're having a whole bunch
of people submit images
that show different findings
and relate that to the prior EDS assessment so
that over time this will grow
and you can use that as a reference material,
which will be available to you as you read these cases
and learn about doing this.
So that is going to be a work in progress.
I'm not sure when we're going to make it available,
but all of this should be available if not
before the RSNA, sometime early next year.
So at a bare minimum, the document itself, if not all
of the appendices should be available pretty soon
within a matter of weeks.

Focus on PI-RADS Assessment

In this talk I'm going to focus on
PI RADS assessment.
We already covered this.
So just to reiterate,
it's based on the MR scan.
There's a five point scale for T two and DWI
and a two point scale for DCE.
It's either positive or negative.
And then you integrate these
and you come up with an assessment category,
which is also a five point scale based on the likelihood
or the probability of clinically significant cancer.
And in the pz, the peripheral zone DWI is dominant.
And in the transition zone, T two weighted images are the
predominant factor.
And this is the grading
or the assessment categories ranging from one to five,
and it's on a per lesion basis.
And here it is again,
it's really pretty simple once you start using it.
For the peripheral zone dependent,
mostly on DWI transition zone based predominantly on T two.
But again, I wanna emphasize you need
to look at all the images.
You can't just look at the T two or just the DWI.
And there is this sort of gray zone, the
pi rads threes that
there's still a little bit of unclarity about,
but these are the criteria that we're using now.

Caveats in the Document

So in the document,
for each section in the document,
there's a whole series of caveats.
And they're actually called caveats in there
that are, I'd say sort of the consensus learning
of the group, things that we thought it would be important
for you to know about as you read these cases.
That is just hard to put into explicit directions.
But there are things we've learned over time, some
of which may not actually be documented
or well validated in the literature,
but these are consensus caveats.

Assessment Process for Peripheral and Transition Zones

So just getting to this, the whole assessment thing
with the peripheral zone
and DWI, this is the way it works essentially in the
peripheral zone, DWI,
the fusion weighted imaging is the primary determinant with,
for example, if the DWI is four,
this is in the peripheral zone,
and the T two is a two, your PY rads for
that lesion is a four.
And that's reflected in those tables.
I already showed you in the transition zone
where T two weighted imaging is the primary determinant.
If the DWI is four
and the T two is a two, the pyra is a two.
Okay? That's what we mean by weighting
these factors for different parts of the gland.
We heard, you heard extensively about DCE playing a
minor role, and you also Kasha already went over
these criteria for DWI in the peripheral zone,
in the transition zone,
and then T two in the peripheral zone
and the transition zone.
And again, this, I'm hoping within a couple of weeks,
these tables will be available on
the A CR website.
You already heard about DCE either
being positive or negative.
What you'll notice is that the verbiage in some
of the slides I'm showing you may be a little bit,
slightly different than the verbiage you may see in slides
that other people are showing you.
And the reason is that the document is still being sort
of refined based on, as I mentioned, it went out
for a critical review by a whole bunch of radiologists,
the United States, Europe, and including Australia
and Brazil.
And we're integrating those comments in there.
And some of them are leading us to
do some wordsmithing,
but the basic concepts haven't changed fortunately.

Practical Application: Case Examples

Okay, so here's the PI RADS assessment again,
and what I wanna do in the remainder
of this talk is take it out for a drive
and just show you how in practice this is sort
of the way I'm approaching the cases
and everybody else is gonna use this a little bit
differently, but it, I think if you start out
and you do it very methodically,
it'll probably serve you well.
So let's talk about this patient. It's a 58-year-old.
PSA is 9.55.
I still don't have a real good handle on why we're down
to two decimal points for PSA,
but this is what we're getting nowadays
and it seems to be maybe one
of the urologists can comment later.
Biopsy showing a Gleason grade two plus three in two of 12 cores.
And these came positive biopsies.
Not really positive,
but these biopsies came from the left side.
They're not positive in the sense
that they're clinically significant cancer,
but they're positive in the sense
that it's not normal prostate.
So this is the kind of patient particularly as in this one
where there's a very strong family history.
This guy's brother died from metastatic prostate cancer
that you end up doing MRIs on
because what else do you have to offer the patient?
So this patient waited six weeks
after the trans rectal ultrasound guided biopsy
to get his MRI
and see if there's anything else we need
to worry about in his prostate.
So there's a lesion in the peripheral
zone and the arrow was pointing to that lesion.
And since it's, and I'm showing you all the images, the T two weighted images, the DCE and then the DWI
and A DC and the high B value image here.
And this is a calculated high B value image.
So we took the lower B value images and just extrapolated it
and sort of artificially created this high B value image.
So this is in the peripheral zone.
So that means for RAs assessment, we don't have
to worry about the transition zone for this instance.
And we're gonna look at the peripheral zone.
Peripheral zone. We're interested primarily in DWI.
And the images we're primarily interested in are the A DC
map and the high B value,
DWI.
And you can see the arrow is pointing to what appears to be
a nice focal, well circumscribed nodule, which has,
which is nice
and dark on the A DC
and is bright on the DWI.
So that means we go to our PI RADS assessment
for DWI in the peripheral zone
and we look at our scale of one to five.
So which one does this fit into most comfortably?
Four, Right?
So it's either four or five depending on the size, right?
And so we go
and we measure the size, it's one centimeter
And that means we've got a four.
So that's a PY RADS four lesion.
And in this instance, it doesn't matter
what the T two showed us, what the DCE showed us so happened
that they were positive in this case.
But the assessment is based really on the DWI here
and it's a RADS four.
And that means that this clinically significant cancer,
this lesion is likely to be clinically significant cancer.
And depending upon the clinical situation,
but certainly in this guy with this strong family history
and this very high anxiety about prostate cancer,
this is probably gonna go on to be biopsied.

Additional Findings in the Same Patient

Now, same patient, same place.
There's another finding here
and around that little nodule, there's also a diffuse area
of low sort
of mildly low signal on the T two weighted images.
Okay? So we're still in the peripheral zone,
So we're gonna still stick with the peripheral zone here.
We're not worried about the transition zone in
assessing this nodule.
And on the,
so we're focusing on the DWI.
Again, if we look at this thing on the T two
and then look at the corresponding area on the A DC
and the high B value images,
what you see here is it looks sort of like diffuse,
maybe mildly hypo intense on the A, DC
and maybe mildly hyperintense on the
DW on the high B value DWI.
So what are we looking at here?
On a scale of one to five,
it fits probably into this.
It's indistinct and it's a hypo, you know, sort
of mildly hyperintense on a DC, okay?
It really wasn't focal.
Go back and well here, I'll show it to you again.
Okay, we'll go, we'll see it in a moment.
But, so looking at this scale,
this is gonna be a RADS two.
Here's the finding again. Okay.
It's not really focal, it's more sort
of diffuse and it'll defined.
And so what we say here is this is clinically significant,
cancer is unlikely, and it could be prostatitis.
Now I wanna make this it clear.
It doesn't mean it's absolutely not Cancer
Could be cancer, it's just not likely.
Okay, but wait, there's more even on the same slice,
we're just looking at one slice by the way,
'cause we haven't looked at the transition zone yet.
There's also something here in the transition zone on the
left side, the arrow's pointing to it.
So transition zone means
that we're going to use as our primary
determinant, T two eight images.
So let's see, here's the magnification of this.
Here's the finding right here that we're interested in
on this grading system.
Where would this fit in from one to five?
Okay, well it's looks like it's non circumscribed,
it's pretty homogeneous, moderately hyperintense,
and it's a pretty big thing.
So we'd give this a five. Okay?
And so your PY RADS assessment,
since you're in the transition zone,
it's based primarily on the T two.
We would give this a five overall.
And we would say that clinically significant cancer is
highly lock likely.
And in a patient like this, this is a good area to go biopsy
with a targeted biopsy,
Okay?
And again, you would have to evaluate the entire prostate.
I just showed you one slice
and pick the four things that you think are most likely
to be clinically significant cancer.
In a patient like this.
You may want to outline more,
you may wanna point out others.
It's really depends on what kind of arrangement you have with
the urologist that you're working with.

Different Patient: Multiple Findings

Now this is a different patient.
And in this patient, here's the T two weighted images
and there's a whole bunch of little thingies here.
Hypo intense areas on the T two weighted images
in the peripheral zone.
Here's the DWI. So what can we say about this?
DWI? Yeah, it stinks.
Okay, so this is important.
You can't use that DWI,
You saw a bunch of cases like this.
Other people have shown you sometimes the
DWIs don't come out.
Well, and this was all the images I've showed you
by the way are done without an endo rectal coil just with the phased array coil, external surface coils, not
with the endorectal coil.
So this is a caveat from the PY RADS document.
If a component of the multiparametric MRI exam,
T 2D WI or DCE is technically inadequate
or is not performed, it's assigned an assessment category
XX means it's technically not adequate to evaluate
or it just wasn't done.
And that happens sometimes the patient's crap out on you before you're done with the exam.
Since DWI is so vital, remember,
most of the cancers are in the peripheral zone
and we keep telling you that DWI is the key sequence that we need to evaluate the peripheral zone.
If the DWI is inadequate,
then it should prompt either a repeat of the exam of
that part of the exam.
If you can remedy
the cause sometimes things you can actually fix them, you,
if you're monitoring it,
something was done wrong, you can make it better.
And Andy already showed you one example
of just changing the phase in coding direction
can sometimes make it better.
And I'll show you some other examples of things
that you can do, but it should be noted if you can't get it
right, that this is a serious limitation
and it needs to be noted in the report.
We've had too many reports
that the poor urologist gets saying there's no, you know,
we don't see anything suspicious,
but then you look at the diffusion weighted
images and they stink.
And so we can't have it both ways.
So we have to make it clear in the report if part
of the examination is inadequate
and acknowledge that this limits the value of the exam.
We've also, in the PI rads document included assessment when
the DWI is in inadequate
'cause that's the of the sequences that you use.
The DWI is the one
that most commonly is technically inadequate
for one reason or another.
And so what we're saying is
that's a category X of its inadequate.
And then for the most part,
your evaluation is gonna be based on T two weighted images,
except in this range here in the threes where
the DCE would help you go one way or the other.
Okay? But this is gonna be primarily useful, frankly,
if you don't have the DWI for staging, it is not gonna be
as useful for evaluating for the presence
or absence of cancer within the prostate gland.

Conclusion

Okay? So we've endeavored with the
Pi Rads version two to make things as simple
as possible so that people will actually use it.
And again, we have no illusions
or misconceptions that this is perfect
and that it works for every single case.
But for the vast majority of cases that you'll see
and the vast majority of findings,
you'll see if you follow these sort of simple step-by-step wave evaluating things,
you'll probably be okay.
Thank you.