[Intl_DxMedPhys] [External] Re: ACR NM Image Acquisition - Discrepancy

[Gretchen Raterman Bell]

👍

Gretchen Raterman Bell reacted via Gmail
<https://urldefense.com/v3/__https://www.google.com/gmail/about/?utm_source=gmail-in-product&utm_medium=et&utm_campaign=emojireactionemail*app__;Iw!!KGKeukY!zWF95Rpi3hI1jvZhScjwt4Q1USBubMEXt_PcT28FZBt0X8DdoMsHlbWcgEGuZ5u6mGUJZsDluyLAGk6ZiEF8V976N3s5VtOf6dOoIt21MeuxUfSM$ >

On Wed, Nov 5, 2025 at 3:07 PM Gress, Dustin <dgress at acr.org> wrote:

> Good discussion. Additional clarification:
>
>
>
> The website screenshot (10M counts) is giving requirements for submissions
> (link
> <https://urldefense.com/v3/__https://accreditationsupport.acr.org/support/solutions/articles/11000062798-phantom-images-nuclear-medicine__;!!KGKeukY!zWF95Rpi3hI1jvZhScjwt4Q1USBubMEXt_PcT28FZBt0X8DdoMsHlbWcgEGuZ5u6mGUJZsDluyLAGk6ZiEF8V976N3s5VtOf6dOoIt21MbZfJ701$ >
> ).
>
>
>
> The QC manual screenshot (30M counts) is what ACR recommends for the
> intrinsic uniformity test during the physicist’s annual survey, providing
> specificity to the QC tests listed at this link
> <https://urldefense.com/v3/__https://accreditationsupport.acr.org/support/solutions/articles/11000061046-quality-control-nuclear-medicine__;!!KGKeukY!zWF95Rpi3hI1jvZhScjwt4Q1USBubMEXt_PcT28FZBt0X8DdoMsHlbWcgEGuZ5u6mGUJZsDluyLAGk6ZiEF8V976N3s5VtOf6dOoIt21MRNIhBRL$ >
> .
>
>
>
> Thanks,
>
> Dustin
>
>
>
> *Dustin A. Gress, MS, FACR, FAAPM*
>
> *Senior Advisor for Medical Physics*
>
> *American College of Radiology*
>
> *dgress at acr.org <dgress at acr.org>* | 703.648.2905
>
> *LinkedIn <https://urldefense.com/v3/__http://www.linkedin.com/in/dustin-gress__;!!KGKeukY!zWF95Rpi3hI1jvZhScjwt4Q1USBubMEXt_PcT28FZBt0X8DdoMsHlbWcgEGuZ5u6mGUJZsDluyLAGk6ZiEF8V976N3s5VtOf6dOoIt21MTirmIOD$ >* | *twitter:
> @DustinGress <https://urldefense.com/v3/__https://x.com/DustinGress__;!!KGKeukY!zWF95Rpi3hI1jvZhScjwt4Q1USBubMEXt_PcT28FZBt0X8DdoMsHlbWcgEGuZ5u6mGUJZsDluyLAGk6ZiEF8V976N3s5VtOf6dOoIt21MYkVZWe2$ >*
>
>
>
> *From:* Intl_dxmedphys_wd_osu_list <
> intl_dxmedphys_wd_osu_list-bounces at lists.osu.edu> *On Behalf Of *Mike
> Nimmo via Intl_dxmedphys_wd_osu_list
> *Sent:* Wednesday, November 5, 2025 3:56 PM
> *To:* Gretchen Raterman Bell <gretchen.raterman at gmail.com>
> *Cc:* Gretchen Raterman Bell via Intl_dxmedphys_wd_osu_list <
> intl_dxmedphys_wd_osu_list at lists.osu.edu>
> *Subject:* [External] Re: [Intl_DxMedPhys] ACR NM Image Acquisition -
> Discrepancy
>
>
>
> *CAUTION: *This email originated from outside of the organization. Do not
> click links or open attachments unless you recognize the sender and know
> the content is safe.
>
>
>
> No. And maybe that's the point. Since ACR evaluates the images
> qualitatively, maybe 10 million counts is enough to evaluate artifacts. But
> due to counting statistics per pixel, you have a decent chance to fail a
> UFOV or CFOV differential
>
> No. And maybe that's the point. Since ACR evaluates the images
> qualitatively, maybe 10 million counts is enough to evaluate artifacts. But
> due to counting statistics per pixel, you have a decent chance to fail a
> UFOV or CFOV differential or integral uniformity test against manufacturer
> specifications at 10 million that you would otherwise pass at 17 or 30
> million.
>
>
>
> In my old life as residency faculty, these counting statistics questions
> were a favorite to plague my residents with! Good question, Gretchen!
>
>
>
> Mike Nimmo
>
>
>
> On Wed, Nov 5, 2025, 2:53 PM Gretchen Raterman Bell <
> gretchen.raterman at gmail.com> wrote:
>
> Thank you for the explanation, Mike.  Official nonuniformity numbers for
> "peak performance" should be done with 17-30 million.  The nonuniformity
> numbers will be better (or the same if there truly is a problem) when going
> from 10 to 30 million count statistics.  I would surmise that if you get
> acceptable numbers with 10 million, then the 30 million count flood may not
> be necessary.  However, from your experience, has there ever been an
> artifact that was seen at 30 million counts that would be possibly covered
> up by the noise in a 10 million flood?  I ask because we have run higher
> counts as a sanity check when we have gotten poor numbers, and the number
> typically stays the same.
>
> Gretchen R. Bell, M.S., DABR
> Diagnostic Imaging Physicist
> Ochsner Medical Center
> (504)842-8506
>
>
>
>
>
> On Wed, Nov 5, 2025 at 2:16 PM Mike Nimmo <mike.t.nimmo at gmail.com> wrote:
>
> Hi Gretchen
>
>
>
> I think the disparity is between acr flood images for submission and
> annual QC. TG177 lists a table of count statistics outlining why at least
> 17 million counts should be acquired for annual testing, but it recommends
> 30 million.
>
>
>
> Honestly I've always wondered why the ACR is so low. I always do at least
> 17 million counts for my annual testing.
>
>
>
> Mike Nimmo
>
>
>
> On Wed, Nov 5, 2025, 2:06 PM Gretchen Raterman Bell via
> Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list at lists.osu.edu>
> wrote:
>
> Hey everyone, My team and I noticed a discrepancy between the ACR NM QC
> manual and the "Phantom Testing" guidance page on their website: We've of
> course always done 10 million (and previously 5 million).   Is this a
> typo in the
>
> Hey everyone,
>
>
>
> My team and I noticed a discrepancy between the ACR NM QC manual and the
> "Phantom Testing" guidance page on their website:
>
>
>
>
>
>
>
> We've of course always done 10 million (and previously 5 million).  Is
> this a typo in the ACR NM QC Manual?
>
> Gretchen R. Bell, M.S., DABR
> Diagnostic Imaging Physicist
> Ochsner Medical Center
> (504)842-8506
>
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> ______________________________________________________________________
>
> This message (including any attachments) is intended only for the use of
> the individual or entity to which it is addressed. It may contain
> information that is non-public, proprietary, privileged, confidential, and
> exempt from disclosure under applicable law and/or may constitute attorney
> work product. If you are not the intended recipient, do not use,
> disseminate, distribute, or copy this communication. If you have received
> this communication in error, please notify us immediately by telephone and
> destroy this message if this is a facsimile or (ii) delete this message
> immediately if this is an electronic communication.
>
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> ______________________________________________________________________
>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: text/vnd.google.email-reaction+json
Size: 37 bytes
Desc: not available
URL: <https://lists.osu.edu/mailman/private/intl_dxmedphys_wd_osu_list/attachments/20251105/bfcfc5d4/attachment.bin>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.osu.edu/mailman/private/intl_dxmedphys_wd_osu_list/attachments/20251105/bfcfc5d4/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.png
Type: image/png
Size: 31052 bytes
Desc: not available
URL: <https://lists.osu.edu/mailman/private/intl_dxmedphys_wd_osu_list/attachments/20251105/bfcfc5d4/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.png
Type: image/png
Size: 34639 bytes
Desc: not available
URL: <https://lists.osu.edu/mailman/private/intl_dxmedphys_wd_osu_list/attachments/20251105/bfcfc5d4/attachment-0001.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.png
Type: image/png
Size: 34639 bytes
Desc: not available
URL: <https://lists.osu.edu/mailman/private/intl_dxmedphys_wd_osu_list/attachments/20251105/bfcfc5d4/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.png
Type: image/png
Size: 31052 bytes
Desc: not available
URL: <https://lists.osu.edu/mailman/private/intl_dxmedphys_wd_osu_list/attachments/20251105/bfcfc5d4/attachment-0003.png>