[Intl_DxMedPhys] Siemens MRI ACR protocol

Wed Nov 12 16:13:30 EST 2025

Thanks for the response, Bob.

I agree with your perspective. But sometimes our perspective does not align with accreditation requirements. My aim was to separate what’s required from what is a good practice.

Robert J. Kobistek, MS, FACR, DABR, MRSE(MRSC™)
Medical Physicist
RJK Medical Physics, Inc.
440-463-7879

From: Bob Bell <bell3660 at sbcglobal.net>
Sent: Wednesday, November 12, 2025 4:01 PM
To: Hardy, Peter A. <peter.hardy at uky.edu>; Gretchen Raterman Bell <gretchen.raterman at gmail.com>; Bob Kobistek <bob at rjkmedphys.com>
Cc: kenharper14 via Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list at lists.osu.edu>
Subject: Re: [Intl_DxMedPhys] Siemens MRI ACR protocol

Hi Bob,

Thanks for raising the issue of ACR accreditation review.  Appropriate filter use is up to the ACR technical subcommittee to determine, and I have no recommendations in this area.

I was commenting from the perspective of one doing annual MRI performance testing.  As such, I think it's improper to use filters that are not commonly used clinically to evaluate system capabilities.  I strive to conduct a fair evaluation based on the unit presented.  For example, it's fine to use SCIC/PURE or SCENIC for GE, Prescan Normalize for Siemens or CLEAR for Philips since these correction algorithms are routinely used clinically.  But if I have to turn off the Fermi filter (NOFERMI) under the GE control variables to get a system to pass ACR resolution tests, it's a bridge too far since this K-space weighting is routinely employed on GE units.

Per clinical protocols, it's unclear to me why the ACR continues to demand their inclusion in the required phantom scans for accreditation submission.  Originally, this was a mechanism to allow some MRI units an alternate way to pass some tests if they could not employ ACR protocols.  However, those days are long past.  Perhaps their inclusion has merit to verify that local clinical head T1 and T2 studies meet ACR clinical head resolution minimums but that's the only reason I can think of.

Be well,

Bob Bell
760-579-3929

On Tuesday, November 11, 2025 at 02:06:25 PM PST, Bob Kobistek <bob at rjkmedphys.com<mailto:bob at rjkmedphys.com>> wrote:

See Doug Pfeiffer’s contribution to this thread. I believe he is on the accreditation committee. According to him, the only “filter” that we can’t use on the phantom images is AI.

My skepticism lies in the fact that, as an ACR phantom reviewer, I see the scan options used on the ACR protocols and the site protocols. As far as I can remember, I was never instructed to compare options to be sure no one was slipping in a filter to cheat.

Also, one can argue that if, for example, the clinical protocol uses a 256 x 192 matrix, then the ACR phantom protocols will always have better high contrast resolution than the clinical scans because they use a 256 x 256 matrix.

Early this morning, before Doug responded, I sent an Email to Marcello Acosta at the ACR, but he’s out of the office until Monday.

BTW, I do remember the practice of chilling phantoms in the refrigerator back in the days of 0.2T and 0.3T magnets. I also remember an ACR FAQ stating that this was a “no no.”

Robert J. Kobistek, MS, FACR, DABR, MRSE(MRSC™)

Medical Physicist

RJK Medical Physics, Inc.

440-463-7879

From: Hardy, Peter A. <peter.hardy at uky.edu<mailto:peter.hardy at uky.edu>>
Sent: Tuesday, November 11, 2025 4:39 PM
To: Bob Bell <bell3660 at sbcglobal.net<mailto:bell3660 at sbcglobal.net>>; Gretchen Raterman Bell <gretchen.raterman at gmail.com<mailto:gretchen.raterman at gmail.com>>; Bob Kobistek <bob at rjkmedphys.com<mailto:bob at rjkmedphys.com>>
Cc: kenharper14 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>>
Subject: RE: [Intl_DxMedPhys] Siemens MRI ACR protocol

This is an important discussion.

I think the flaw in the argument that we should be testing the scanner in the same condition as is used clinically is that there is very little carry over in the protocol between what is done for the ACR measurements and what is done clinically, at least for most institutions. Recognizing that, the ACR requires a submission to include images using both the ACR AxT1 & AxT2 protocol and the equivalent clinical AxT1 & AxT2 scans. If either set of scans passes the required resolution, slice thickness, SNR, etc, the scanner passes the test. In the clinical scans we are not required to use or not use low pass or high pass filters. My own view of removing the in-line filter during a test is that it assesses the scanner in its rawest form. I don’t see any difference turning that filter off and removing any of the filters, such as elliptical filters, available in the RESOLUTION scan card or setting the RF profile to NORMAL. We may not use RF=NORMAL in our clinical settings but using it for the test gives a uniform assessment of the scanner’s performance.

Peter Hardy, PhD, DABMP

Associate Professor of Radiology, Neuroscience and Biomedical Engineering

Faculty, Division of Diagnostic & Nuclear Medical Physics

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: peter.hardy at uky.edu<mailto:peter.hardy at uky.edu>

From: Bob Bell <bell3660 at sbcglobal.net<mailto:bell3660 at sbcglobal.net>>
Sent: Tuesday, November 11, 2025 4:23 PM
To: Hardy, Peter A. <peter.hardy at uky.edu<mailto:peter.hardy at uky.edu>>; Gretchen Raterman Bell <gretchen.raterman at gmail.com<mailto:gretchen.raterman at gmail.com>>; Bob Kobistek <bob at rjkmedphys.com<mailto:bob at rjkmedphys.com>>
Cc: kenharper14 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>>
Subject: Re: [Intl_DxMedPhys] Siemens MRI ACR protocol

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Hi Bob,

I don't recall a direct ACR reference for this policy but do recall discussions among the ACR MRI Technical Subcommittee members that no changes to a protocol should be allowed that were not also applied to normal clinical imaging.  To do so would gut the basis of MRI performance testing by allowing technical results that could not be accomplished clinically.

Features of the initial ACR MRI phantom were designed to ensure fair testing by eliminating ways one could bias results.  For example, slice thickness, resolution and bandwidth (indirectly from the fat/water inserts) are all assessed simultaneously in the ACR T1 axial series.  One can't artificially increase SNR by using a wider slice thickness, by reducing resolution via a lower matrix or abnormal k-space weighting, or by markedly lowering bandwidth.  I also seem to recall ACR noting not to chill the large ACR MRI phantom prior to testing in order to improve SNR as some did in the early days of low-field systems.

Bob Bell

760-579-3929

On Monday, November 10, 2025 at 08:07:02 PM PST, Bob Kobistek <bob at rjkmedphys.com<mailto:bob at rjkmedphys.com>> wrote:

Is that documented somewhere on the ACR website?

Robert J. Kobistek, MS, FACR, DABR, MRSE(MRSC™)

Medical Physicist

RJK Medical Physics, Inc.

440-463-7879

From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces+bob=rjkmedphys.com at lists.osu.edu<mailto:intl_dxmedphys_wd_osu_list-bounces+bob=rjkmedphys.com at lists.osu.edu>> On Behalf Of Bob Bell via Intl_dxmedphys_wd_osu_list
Sent: Monday, November 10, 2025 8:01 PM
To: Hardy, Peter A. <peter.hardy at uky.edu<mailto:peter.hardy at uky.edu>>; Gretchen Raterman Bell <gretchen.raterman at gmail.com<mailto:gretchen.raterman at gmail.com>>
Cc: kenharper14 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>>
Subject: Re: [Intl_DxMedPhys] Siemens MRI ACR protocol

Hi all, Just a quick comment on this email chain. It's my understanding ACR allows any filters or instrument settings routinely used for patient studies to be used for phantom studies but does not allow filters/settings unique to phantom studies

Hi all,

Just a quick comment on this email chain.  It's my understanding ACR allows any filters or instrument settings routinely used for patient studies to be used for phantom studies but does not allow filters/settings unique to phantom studies alone.  Employing filters/settings that are not used for patient studies defeats the purpose of annual testing by artificially altering instrument performance from normal clinical practice.  For example, it's okay to use prescan normalize on Siemens units to improve IIU as long as it is also used for patient studies.  However, altering filters/settings to those not common for clinical studies just to improve instrument phantom performance is a no no.

Bob Bell

On Friday, November 7, 2025 at 06:29:18 AM PST, 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:

For what it's worth, I'll summarize some settings I've gotten from both the DXlist and from Siemens that have helped tremendously. I work on both Aeras and Solas. To improve signal uniformity: - Use B1 filter - Use sum of squares

For what it's worth, I'll summarize some settings I've gotten from both the DXlist and from Siemens that have helped tremendously.  I work on both Aeras and Solas.

To improve signal uniformity:

- Use B1 filter

- Use sum of squares (coil combination)

To improve spatial resolution, particularly Solas:

  *   Resolution tab --> B1 Filter should be ON
  *   Elliptical Filter should be OFF
  *   Prescan Normalize should be ON
  *   Sequence tab --> Gradient Mode should be NORMAL or FAST
  *   Sequence tab --> RF pulse types, try different SAR settings (try this very last, he was unsure about this one)
  *   If none of this improves the high contrast resolution, he highly recommended calling into the  1800 number for remote service:

     *   In-Line Image Filter should be turned OFF
     *   This is a global setting that only FSE or remote service can modify; must be turned back on after acquiring phantom images
     *   It tends to be an overall smoothing filter
     *   Particularly affects newer software, which is likely why we don’t see it on the Aeras

FYI, I haven't had to do that last bullet point yet, but good to know just in case.

Gretchen R. Bell, M.S., DABR
Diagnostic Imaging Physicist
Ochsner Medical Center
(504)842-8506

On Fri, Nov 7, 2025 at 8:12 AM Hardy, Peter A. 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:

It might be easier to import an .exar file. These are available from Siemens on their Phoenix site. ACR Phantom QA Test I’m attaching the file for a 1. 5T system. Similar files are available for other systems and OS levels. This protocol likely

It might be easier to import an .exar file. These are available from Siemens on their Phoenix site.

ACR Phantom QA Test<https://urldefense.com/v3/__https:/www.magnetomworld.siemens-healthineers.com/clinical-corner/protocols/mr-in-rt/acr-phantom-qa-test__;!!KGKeukY!0J5pWek2Y1lqkWdNUarukJAaQxlT5NXRKlh0kmDROFkR-peOYmfS1MRNkentpqiJPmhBL1nfqqpvJzIqMmXyItg3OYVYBOFj01ry3nznJwbc$>

I’m attaching the file for a 1.5T system. Similar files are available for other systems and OS levels.

This protocol likely includes the updated axial T2 sequence.

Peter Hardy, PhD, DABMP

Associate Professor of Radiology, Neuroscience and Biomedical Engineering

Faculty, Division of Diagnostic & Nuclear Medical Physics

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: peter.hardy at uky.edu<mailto:peter.hardy at uky.edu>

From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces+peter.hardy=uky.edu at lists.osu.edu<mailto:uky.edu at lists.osu.edu>> On Behalf Of Adam Springer via Intl_dxmedphys_wd_osu_list
Sent: Friday, November 7, 2025 7:26 AM
To: kenharper14 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>>
Subject: [Intl_DxMedPhys] Siemens MRI ACR protocol

CAUTION: External Sender

Hello, List. I have instructions from Siemens for building the ACR protocol on a Magntom Avanto, from 2005. Does anyone have a more recent set of those instructions? I've had to ask Siemens to reload their ACR protocol at a couple sites recently,

Hello, List.

I have instructions from Siemens for building the ACR protocol on a Magntom Avanto, from 2005. Does anyone have a more recent set of those instructions? I've had to ask Siemens to reload their ACR protocol at a couple sites recently, and it would be convenient if I could just change the settings while I'm on site.

Happy Friday!

Adam

========================
Adam C. Springer, MS, DABR®
Medical Physicist & CEO
KLS Physics Group, LLC
124 Killgore Rd
Ruston, LA 71270
Office: 318-255-5033
Mobile: 318-272-8292

[2927183d-095e-413d-96b1-930240ed6257]
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