[Intl_DxMedPhys] [EXTERNAL] Re: EXT MSG Fwd: The New CMS Measure: Methods for Size-Adjusted Dose and Their Variabilities

Tue Mar 11 18:56:56 EDT 2025

Jie,

                Interesting paper, it is a concern several on this list have been investigating for a while and this work is a nice summary of concerns of the potential variation in SAD.  I did have a technical question, in my investigation of attempting to validate the measure (and potential calculations from software implementations) the major issue I had was getting the d_k (“expected diameter”) value for each of the protocols.  I looked in the references you provide and they are both ones that I have looked at in the past.  Can you illuminate how the d_k value was determined for your SAD calculation?  I think I found a specific table with the beta_k values, but I could never find the expected diameter.

                In your text you write that “The values for d_k and beta_k are derived from the UCSF International CT Dose Registry and specified in the measure for each of the 18 CT categories”.  I don’t know that I have been able to find the d_k values in the measure documents, either.

Thanks,
Isaac

Isaac Rutel, Ph.D., DABR
Associate Professor
Dept. Radiological Sciences
OUHSC
405-596-2623

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From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces at lists.osu.edu> On Behalf Of Jie Zhang via Intl_dxmedphys_wd_osu_list
Sent: Tuesday, March 11, 2025 3:30 PM
To: Gauntt, David <davidgauntt at uabmc.edu>
Cc: DxMedPhys List <intl_dxmedphys_wd_osu_list at lists.osu.edu>
Subject: [EXTERNAL] Re: [Intl_DxMedPhys] EXT MSG Fwd: The New CMS Measure: Methods for Size-Adjusted Dose and Their Variabilities

Hello David, As I mentioned early, we have performed calculations using both methods from Wisconsin and Duke groups and compared the results across selected protocols from 18 categories defined by CMS. We are going to share our findings soon. 
Hello David,

As I mentioned early, we have performed calculations using both methods from Wisconsin and Duke groups and compared the results across selected protocols from 18 categories defined by CMS. We are going to share our findings soon.

Jie

On Tue, Mar 11, 2025 at 4:02 PM Gauntt, David <davidgauntt at uabmc.edu<mailto:davidgauntt at uabmc.edu>> wrote:

Justin,

Loretta Johnson recently found an article by Christian, Samei, et al, that described a technique for measuring the global noise; I suspect that the link you displayed was the same paper or a follow up to it.  So far as I know the big problem remains that neither CMS nor Alara nor Imalogics describe how glocal noise is calculated.  I suspect that Imalogics uses the method described in the papers from Duke since Olav C. is one of the co-authors of those papers, but can only guess what Alara does or what CMS requires.

---
David M. Gauntt, Ph.D.
Associate Professor
Division of Physics and Engineering
Department of Radiology
(205)975-3777

[1647458080270]

________________________________
From: Justin Solomon <justin.solomon at duke.edu<mailto:justin.solomon at duke.edu>>
Sent: Tuesday, March 11, 2025 1:42 PM
To: Jie Zhang
Cc: Gauntt, David; DxMedPhys List
Subject: Re: [Intl_DxMedPhys] EXT MSG Fwd: The New CMS Measure: Methods for Size-Adjusted Dose and Their Variabilities

I believe most commercial offerings that do CT global noise measurements follow some variant of this method: https://urldefense.com/v3/__https://pubmed.ncbi.nlm.nih.gov/26102424/__;!!KGKeukY!yB1ffr7b6pMzK45TrjKvRzw7zpCB9-v8bAOsEaKOj2fRG6pSeuciwIWO7Dma1q6XGYhG40LzFPHr56m4BR6-3VsrPBFmSYrDvqzFSlFqwlGjEw$ <https://urldefense.com/v3/__https:/pubmed.ncbi.nlm.nih.gov/26102424/__;!!NoSwA-eRAg!F3lGV84p_jwyFoJiRksbdPUxg39amA4RqRJ7s6qm4MPTiXOvyOrK5ljU5myvmyur_vucHcoTZgZTS-AX3S7rwc5uiLKS8zg$>

There are some details/parameters that could vary between implementations. Would be an interesting study to compare vendors with a common dataset.

That’s said we’ve had an in house built system making these measurements for many years now. In my experience the challenging part of using those data is sorting through meta data / protocol / series naming inconsistencies when doing aggregated analysis. I’m guessing those sources of variability and uncertainty dwarf the variability due to global noise measurement implementation.

Cheers,
Justin
————————
Justin Solomon, PhD DABR
Radiation Physicist
Duke Health
919-684-1441

On Mar 11, 2025, at 9:51 AM, Jie Zhang 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:

Yes. We have also investigated global noise metrics and their potential limitations in clinical applications. We are wrapping up our writing and hope to share our results soon. Thanks! Jie On Tue, Mar 11, 2025 at 11: 32 AM Gauntt, David <davidgauntt@ uabmc. edu>
Yes. We have also investigated global noise metrics and their potential limitations in clinical applications. We are wrapping up our writing and hope to share our results soon.

Thanks!

Jie

On Tue, Mar 11, 2025 at 11:32 AM Gauntt, David <davidgauntt at uabmc.edu<mailto:davidgauntt at uabmc.edu>> wrote:

Jie,

Does your paper  address the issue of image quality?

The new CMS measure addresses both dose and image quality, using "global noise" as a measure of image quality.  However, as near as I can tell the measure does not address how you measure "global noise" in a clinical image, and have not found any papers from the measure's stewards addressing this issue.

Does anyone have any references to anything addressing how you calculate global noise?

---
David M. Gauntt, Ph.D.
Associate Professor
Division of Physics and Engineering
Department of Radiology
(205)975-3777

<OutlookEmoji-1647458080270d7f02ca5-59f0-4d92-8fab-6fcda46b3f08.png>

________________________________
From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces+davidgauntt=uabmc.edu at lists.osu.edu<mailto:uabmc.edu at lists.osu.edu>> on behalf of Jie Zhang 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>>
Sent: Tuesday, March 11, 2025 10:04 AM
To: intl_dxmedphys_wd_osu_list at lists.osu.edu<mailto:intl_dxmedphys_wd_osu_list at lists.osu.edu>
Subject: EXT MSG [Intl_DxMedPhys] Fwd: The New CMS Measure: Methods for Size-Adjusted Dose and Their Variabilities

Thanks to Dr. Wunderle! I originally posted this to the old listserver and am now forwarding it to the new Dx list. I am sorry if you receive it twice. Jie ---------- Forwarded message --------- From: Jie Zhang <jzctjmn@ gmail. com> Date: 
Thanks to Dr. Wunderle! I originally posted this to the old listserver and am now forwarding it to the new Dx list.  I am sorry if you receive it twice.

Jie
---------- Forwarded message ---------
From: Jie Zhang <jzctjmn at gmail.com<mailto:jzctjmn at gmail.com>>
Date: Tue, Mar 11, 2025 at 9:15 AM
Subject: The New CMS Measure: Methods for Size-Adjusted Dose and Their Variabilities
To: DXIMGMEDPHYS at HERMES.GWU.EDU<mailto:DXIMGMEDPHYS at HERMES.GWU.EDU> <dximgmedphys at hermes.gwu.edu<mailto:dximgmedphys at hermes.gwu.edu>>

Dear Colleagues,

The new CMS guidance on excessive radiation measurement allows flexibility in software selection, but this may lead to inconsistencies and undermine its goal.

We recently evaluated five methods for estimating effective diameter and their impact on Size-Specific Dose Estimate (SAD) in thoracic and abdominal CT. A retrospective analysis of 719 exams revealed inconsistencies in SAD methods, dose thresholds, and application across patient populations and institutions. Addressing these issues is critical for accurate dose reporting and diagnostic integrity.

Our manuscript is available on arXiv: https://urldefense.com/v3/__https://arxiv.org/abs/2503.06644__;!!KGKeukY!yB1ffr7b6pMzK45TrjKvRzw7zpCB9-v8bAOsEaKOj2fRG6pSeuciwIWO7Dma1q6XGYhG40LzFPHr56m4BR6-3VsrPBFmSYrDvqzFSlEG1zLzhQ$ <https://urldefense.com/v3/__https:/arxiv.org/abs/2503.06644__;!!KGKeukY!wkvI7i3VRXaaElI73WdyPRf_Zk6qQqZ2CCRW0BoG-aYbTN1bVG_WIFbTeFOBYzuVEpUvax1OJJGkFDM4g68KPmxld3yXDnHKjwB6aQ$>.

Our findings reinforce concerns raised by the AAPM Commissioned Panel, recently published in AJR, and we hope to provide a technical perspective on the CMS measure.

Best Regards,

Jie
Jie Zhang, PhD, DABR (D, N), FAAPM
Professor of Radiology and Biomedical Engineering
Chief, Division of Diagnostic & Nuclear Medical Physics
Program Director, Diagnostic Imaging Physics Residency
Department of Radiology
University of Kentucky College of Medicine
UK HealthCare
800 Rose Street, Room HX-307
Lexington, KY 40536-0293
Phone: (859) 323-2954
Email: jnzh222 at uky.edu<mailto:jnzh222 at uky.edu>

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