[Intl_DxMedPhys] MQSA - Manufacturer PM vs ACR DM QC manual

Mon Jun 1 13:23:35 EDT 2026

I agree with what you have described Chikezie, however, our MQSA inspectors are holding us to PM failures and citing us for it for not fixing HVL immediately before clinical use.

To complicate matters, when they recalibrate HVL, they technically have to recalibrate AEC. Per the ACR DM QC manual, if there is AEC recalibration that affects dose - technically any recalibration would affect dose and a physicist would need to do on-site testing post recalibration.

________________________________
From: Chikezie C. Onyema <onyema.cc at gmail.com>
Sent: Monday, June 1, 2026 12:14 PM
To: Milman, Rebecca <REBECCA.MILMAN at cuanschutz.edu>
Cc: Tao, Ashley T <attao at emplifyhealth.org>; DxMedPhys List <intl_dxmedphys_wd_osu_list at lists.osu.edu> <intl_dxmedphys_wd_osu_list at lists.osu.edu>
Subject: Re: [Intl_DxMedPhys] MQSA - Manufacturer PM vs ACR DM QC manual

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Hi,

My understanding is that the tolerance level set by Hologic and checked by FSE during PMs is tighter than the one specified in the QC manual. The image below shows a snapshot of a tube output measurement done by FSE during PM. An FSE typically uses a dosimeter (in our case, Raysafe X2) to measure the tube output and HVL at different kV settings, then compares them against set specification values. It is my understanding that if it is out of spec, the FSE can increase/decrease the X-ray tube output to meet the specification (and pass the tube output tests), which may require a total recalibration of the unit, including dose measurement. It is possible that some measurements may pass per the QC manual, whereas during PM the same measurement may be out of spec due to tighter tolerances.
[IMG_1368.jpeg]

Thanks
Chikezie Onyema, PhD, DABR
Diagnostic Medical Physicist
Department of Radiology
Marshfield Clinic | Sanford Health
Marshfield, WI 54449

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On Mon, Jun 1, 2026 at 11:21 AM Milman, Rebecca 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:
Update: I just received a PM service report (from Hologic) that stated that, “System passed all tests…to the exception of tube output and dose for all techniques. ” This raises a couple of questions, and I’m interested in other people’s experiences. 
Update:

I just received a PM service report (from Hologic) that stated that, “System passed all tests…to the exception of tube output and dose for all techniques.”

This raises a couple of questions, and I’m interested in other people’s experiences.

As a physicist, I don’t really know what it means if the “tube output and dose for all techniques” doesn’t pass during a PM. Without more information - including their internal pass/fail criteria - I’m not sure how to interpret this service report.

The other issue is related to Ashley’s original post. If the manufacturer’s tolerance for HVL is 0.01 mm Al, then it is problematic when you’re measuring HVL with a device with a measurement error > 0.01 mm Al. My experience has been that Hologic FSEs use the Raysafe X2 systems, which have a measurement error of 5% (below 25 kV) or 10% (above 25 kV). For a system with an HVL ~ 0.5 mm Al at 28 kV, then the measurement error is well above 0.01 mm Al.

So how do we (QMPs) address the situation where a manufacturer cites an issue based on a problematic performance criterion? For any other modality I would make a note of why the manufacturer’s criteria are problematic, but with the added regulatory requirements of mammography and the authority that MQSA wields over us all, what is a reasonable approach?

Should we start reporting measured values as a range of values to represent errors in the measurement equipment? There are regulations saying that manufacturers need to provide the facility with a service report, but how much information are they required to provide? It seems reasonable that they would need to provide a description of the test that failed and what their measurements were, but does anyone get that in their service reports?

Rebecca.

Rebecca Milman, Ph.D., DABR
Division Chief, Radiological Sciences | Associate Professor
Department of Radiology
University of Colorado Anschutz
720.848.6625

From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces at lists.osu.edu<mailto:intl_dxmedphys_wd_osu_list-bounces at lists.osu.edu>> on behalf of Tao, Ashley T 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>>
Date: Tuesday, May 19, 2026 at 2:27 PM
To: DxMedPhys List
<intl_dxmedphys_wd_osu_list at lists.osu.edu<mailto:intl_dxmedphys_wd_osu_list at lists.osu.edu>>
Subject: [Intl_DxMedPhys] MQSA - Manufacturer PM vs ACR DM QC manual

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Dear DxMedPhys Listerv,

 I am wondering if anyone who is using the ACR DM QC manual has had any experience with MQSA inspectors giving citations for not following up with PM specifications.

Let me set the scene:

  1.
Our biomed engineer performed service on our unit and determined HVL to be outside of Hologic specs of +/-0.01 mm Al from their baseline/reference value. At 28kV, hologic baseline was 0.513 mm Al, and biomed measured 0.517. We were due for annual testing about a month and a half from the discovery. biomed asked if they could schedule PM for the day before physics testing. Since we were well above the minimum HVL requirement of 0.28 mm Al, we agreed.
MQSA inspectors said that ACR DM QC Test summary (mee report), Beam quality (HVL) assessment failures must be corrected before clinical use. Our HVL passes the ACR DM QC manual, but because biomed failed it, they said we needed to correct before clinical use and have an MEE.
  2.
Our biomed engineer performed service on our unit and determined AEC performance to be outside Hologic's specifications @ 2cm. Hologic references a range of EI values, whereas ACR DM QC manual specifies the SNR needs to be within +/-15% of the MEE. These two metrics are not comparable. We did perform a partial MEE because we were not certain whether or not we needed to. It turns out the MEE SNR was 22.34 and after AEC calibration, the new MEE SNR was 22.21. The MEE was completed 34 days after service but we were cited because it needed to be within 30 days. How do you reconcile the metrics used by Hologic vs ACR DM QC manual if they are not comparable?
  3.
Our biomed engineer performed service on our unit and determined target dose to be outside Hologic's specifications of +/-0.1 mGy. The ACR DM QC manual specifies the target dose for a CC view of the ACR DM QC phantom to be <=3 mGy and that the unit AGD must be within +/-25% of the calculated AGD. Again, Hologics metrics are different than the ACR DM QC manual. We are well within specifications, but because biomed failed it and we did not service it within 30 days, we were cited.

We showed the MQSA inspectors the service report and explained what the results were but they didn't seem to care and said that we would need to provide a corrective action letter before escalating to their next level inspector. It is my understanding that Hologic PM specs are more stringent for optimal performance. The ACR DM QC manual does not specify a timeline to address deficiencies in PM except for if there is relevant service and a finding were to be out of compliance with the ACR DM QC manual then you would need appropriate follow-up (e.g. immediately before clinical use versus 30 days). We are writing a response letter addressing these citations, but I would appreciate any input this group may have regarding their experience w/ inspectors and PMs being out of spec.

On a side note, if HVL is out of Hologic spec (but within MQSA requirements), and my biomed engineer needs to recalibrate but it also requires them to recalibrate AEC as part of the process, it seems that there would need to be on-site physicist testing of the AEC because according to  ACR DM QC manual - Table 3 Medical Physicist Involvement in Equipment Adjustments, Changes or Repairs(pg 138) - are any of you basically having to do MEEs every time your PMs are just a little bit out of spec?

Looking forward to hearing about your experiences.

Thanks
Ashley
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