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

[Gress, Dustin]

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!zm7yL3gRWpI1s8aLPljsGPqtM8Gy3uNMjx0dXMJ42R-_0sOAWBC70-UzK3G1dpQBLb9zW9YR47m1vCFOsMDdkeW2CvPr1UDO87c$ >).

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!zm7yL3gRWpI1s8aLPljsGPqtM8Gy3uNMjx0dXMJ42R-_0sOAWBC70-UzK3G1dpQBLb9zW9YR47m1vCFOsMDdkeW2CvPrDS5FrlM$ >.

Thanks,
Dustin

Dustin A. Gress, MS, FACR, FAAPM
Senior Advisor for Medical Physics
American College of Radiology
dgress at acr.org<mailto:dgress at acr.org> | 703.648.2905
LinkedIn<https://urldefense.com/v3/__http://www.linkedin.com/in/dustin-gress__;!!KGKeukY!zm7yL3gRWpI1s8aLPljsGPqtM8Gy3uNMjx0dXMJ42R-_0sOAWBC70-UzK3G1dpQBLb9zW9YR47m1vCFOsMDdkeW2CvPrQwf73-o$ > | twitter: @DustinGress<https://urldefense.com/v3/__https://x.com/DustinGress__;!!KGKeukY!zm7yL3gRWpI1s8aLPljsGPqtM8Gy3uNMjx0dXMJ42R-_0sOAWBC70-UzK3G1dpQBLb9zW9YR47m1vCFOsMDdkeW2CvPrb6IYo6o$ >

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<mailto: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<mailto: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<mailto: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:

[cid:image001.png at 01DC4E6E.463F87D0]

[cid:image002.png at 01DC4E6E.463F87D0]

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 --------------
An HTML attachment was scrubbed...
URL: <https://lists.osu.edu/mailman/private/intl_dxmedphys_wd_osu_list/attachments/20251105/3dab44cb/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.png
Type: image/png
Size: 31052 bytes
Desc: image001.png
URL: <https://lists.osu.edu/mailman/private/intl_dxmedphys_wd_osu_list/attachments/20251105/3dab44cb/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.png
Type: image/png
Size: 34639 bytes
Desc: image002.png
URL: <https://lists.osu.edu/mailman/private/intl_dxmedphys_wd_osu_list/attachments/20251105/3dab44cb/attachment-0001.png>