Re:MRI as a Screening Tool?

[Guest guest]

>

> Can an MRI examination be used as a screening tool when the

> patient has high PSA numbers and a negative biopsy? I have

> been reading the postings to this group for months now. I know

> the importance of an early detection. I also know that

> biopsies can miss. While MRI examinations are used after a

> positive biopsy, I don't read of any cases where a patient

> with consistent elevated PSA readings and negative biopsies

> then undergoes an MRI for the discovery of the cancer. How

> come? What am I missing?

I'm not a doctor much less a radiologist or scanning expert, but

here's how I understand this question from a layman's

perspective.

MRI can produce an image of higher and lower density regions in

the prostate or in other tissue. That can be useful, but it's

not definitive. The presence of high density regions _may_

indicate clumps of tumor cells, but unless a biopsy is done, we

can't know for sure what those high density regions really are.

Also, the tumor cells are not necessarily much higher density and

may not show up well on an MRI.

For both of those reasons, a biopsy is needed to get a definitive

diagnosis.

If the doctor knows that cancer is present due to the biopsy, an

MRI can be helpful in revealing its location and extent. I had

an endo-rectal MRI (an MRI with the antenna twisted up into my

rectum (by a large male nurse with powerful hands - oof) and a

set of images made as part of a clinical trial of MRI guided HDR

brachytherapy. The image was very good and revealed a lot.

However I can testify that that MRI was not particularly more

comfortable than the biopsy was, required more people and

equipment (so probably cost more), and produced a different kind

of information. It showed the shape of the tumor well but did

not reveal Gleason grade or some other diagnostics that the

biopsy revealed.

As I say, I'm no expert. I don't know if that explanation is the

right one.

Alan Meyer

ameyer2@...

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[Guest guest]

Alan:

Sounds right to me, and I agree with the " Ooofff! The only thing that

I would add is that they reported no evidence of spread. The exact

wording of the report: (besides the description of the cancer in the

gland.)The report was signed by an radiation oncologist M. D.

" No signs of extracapsular extension of tumor or pelvic lymphadenopathy. "

Fuller

> >

> > Can an MRI examination be used as a screening tool when the

> > patient has high PSA numbers and a negative biopsy? I have

> > been reading the postings to this group for months now. I know

> > the importance of an early detection. I also know that

> > biopsies can miss. While MRI examinations are used after a

> > positive biopsy, I don't read of any cases where a patient

> > with consistent elevated PSA readings and negative biopsies

> > then undergoes an MRI for the discovery of the cancer. How

> > come? What am I missing?

>

> I'm not a doctor much less a radiologist or scanning expert, but

> here's how I understand this question from a layman's

> perspective.

>

> MRI can produce an image of higher and lower density regions in

> the prostate or in other tissue. That can be useful, but it's

> not definitive. The presence of high density regions _may_

> indicate clumps of tumor cells, but unless a biopsy is done, we

> can't know for sure what those high density regions really are.

> Also, the tumor cells are not necessarily much higher density and

> may not show up well on an MRI.

>

> For both of those reasons, a biopsy is needed to get a definitive

> diagnosis.

>

> If the doctor knows that cancer is present due to the biopsy, an

> MRI can be helpful in revealing its location and extent. I had

> an endo-rectal MRI (an MRI with the antenna twisted up into my

> rectum (by a large male nurse with powerful hands - oof) and a

> set of images made as part of a clinical trial of MRI guided HDR

> brachytherapy. The image was very good and revealed a lot.

>

> However I can testify that that MRI was not particularly more

> comfortable than the biopsy was, required more people and

> equipment (so probably cost more), and produced a different kind

> of information. It showed the shape of the tumor well but did

> not reveal Gleason grade or some other diagnostics that the

> biopsy revealed.

>

> As I say, I'm no expert. I don't know if that explanation is the

> right one.

>

>

> Alan Meyer

> ameyer2@...

>

>

>

________________________________________________________________________________\

____

> Looking for last minute shopping deals?

> Find them fast with Yahoo! Search.

http://tools.search.yahoo.com/newsearch/category.php?category=shopping

>