So, we have a couple of questions from our YouTube channel regarding imaging, and they're
wondering what the difference is between a 1.5 MRI and a 3T MRI?
I'd say the difference between these two different types of MRI—1.5 and 3—have to do with
the magnet strength, and when you get into a stronger field, a 3T MRI, you get more precise,
well-defined, pictures, and when you're imaging a small target like the prostate which is
deep inside the body, that extra magnet strength really makes a difference.
If we see people doing MRIs with 1.5T, we assume that they're just probably not state-of-the-art,
and there is one exception to that: patients that have had hip replacements—the metal
in the hips, which is very close to where the prostate is, causes interference and degrades
image quality in the higher power fields, and the experts tell us that the 1.5 Tesla
MRIs are preferable in people that have had hip replacements that are trying to get good
MRI pictures of the prostate.
So, it's not going to be as good as a 3T, but the 3T field strength when the hip metal
is right next to it causes greater distortion to the picture than a lower field.
So, in those cases with people who have had hip replacements and are gonna get that 1.5
MRI, does that also include that they need to get an endorectal coil as well?
Well, endorectal coils improve picture quality to some degree, and since you are working
with a less powerful field, an endorectal coil might improve the imaging to some degree
and be useful.
So, we have a patient who is in North Carolina, and they're wondering if they should travel
to, like, New York to get a 3T MRI versus a local center.
They're wondering if there is like a world-class operation, like say, Weill-Cornell or something
like that which would be better than anything local to them?
Well, as we've advocated doing MRIs before random biopsies, we're putting an awful lot
of stock in how well the MRI information comes back, and I would never be comfortable just
going to any old facility and saying do an MRI on me and trust my life that when the
report comes back and says there's no cancer present that we can truly trust it because
there's a lot of training that goes into learning how to read MRIs properly, and unfortunately
a lot of the radiologists out there are unaware of their deficiencies, and so they'll read
these things out; maybe someone is paying them to read their MRIs, maybe they're contracted
radiologists, but haven't had the necessary training and experience to really know what
they're looking at.
One way to work around that, of course, is to go ahead and have the MRI done locally,
but then have it overread at a center of excellence.
You mentioned some of the facilities in New York like Cornell, NYU, Memorial Sloan-Kettering;
we're out here on the west coast, UCLA and UCSF, and the images can be sent there on
a disk and read by the physicians at these facilities who are very experienced in reading
prostate MRIs.
So, the two things they'll be looking at are not only is there any unusual spots there—we
call them, you know, they're graded by PI-RADS and if the spots are more suspicious then
some kind of targeted biopsy would be warranted—but they're also looking at the image quality.
So, does the equipment generate adequate high resolution images for interpretation, number
one, and number two, did the people that are taking the pictures—the technicians—adjust
the contrast and all those different factors to ensure images that can be interpreted.
So, all that can be reviewed at a reference center such as the ones I mentioned, and they
can tell you that the images are acceptable or unacceptable, and then, if they are acceptable,
they can be overread at a reference institution.
Rereading an MRI like that, what is the average cost?
And I'm imagining it's not covered by insurance by any means.
I'm not really sure.
We do this a lot and I don't get any complaints, so I don't think it's particularly expensive.
We have another patient who is wondering if an MRI, 3T MRI, is good at finding pelvic
nodes, you know, any kind of cancer on the pelvic nodes, or should they just go to a
PSMA?
Well, nothing compares to a PSMA for finding pelvic nodes.
Up until recently, MRIs and CAT scans were the best we could do, and they were better
than nothing.
They didn't really see the cancer in the lymph nodes the way PSMA does.
What they would look at were the outer dimensions of the lymph nodes, and if they started to
become plump and enlarged because there is so much cancer in them, that is what would
trigger the radiologist to say, "Hey, pay attention, these lymph nodes are too big"
and that could well indicate that there is cancer inside of them, but PSMA PET scans
can actually detect the cancer itself inside the lymph node itself, so you don't have to
have large chunks of tumor to show whether cancer is present or not.
So, there's really nothing that compares to PSMA.
You could argue that maybe Axumin PET scans, C11 PET scans, which also can look at the
cancer inside the lymph nodes are superior to MRI and CAT scans, but in my opinion, PSMA
PET scans are going to offer the most precision.
So, if an MRI or a PSMA does find cancer in the lymph nodes, do they automatically need
to biopsy it?
Does that mean it's a higher grade of cancer?
I mean, it depends so much on the situation.
So if you have someone with a PSA of 60 and you find enlarged lymph nodes on an MRI, I
don't think you need to go biopsying anybody.
The PSMA PET scan is cancer-specific.
So, in a sense, you're almost getting a biopsy.
So, PSMA only lights up for prostate cancer, it's not looking at the dimensions of the
nodes which could be enlarged for a variety of non-cancerous reasons.
It's looking only if cancer is present.
So, people that have had PSMA would typically not need a biopsy to confirm that it's cancer.
You know already that it's cancer.
Hey everybody, it's me and my dog Hunter.
We're giving him treats over here, but yeah, go ahead and check out his Instagram at SirHunterTheDal,
and go ahead and subscribe to our YouTube channel, we come out with new prostate cancer
videos every week; yes we do.