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

[Milman, Rebecca]

Ashley,

Regarding items 1-3, I don't know if this<https://urldefense.com/v3/__https://www.fda.gov/radiation-emitting-products/regulations-mqsa/mqsa-alternative-standard-9-correction-period-when-components-selenia-full-field-digital-mammography__;!!KGKeukY!0jZGzRISk-txBsBcTRp_5rOE6WKPZf3fh4Ga-jKeTOoTBYNUHjCZy9ZVVERPf7Q2_00DcXsuDoGP5Tiz64Nz4mnzDBl-CD2OZiodoLfoxrkvnhbXG_ZDfA$ > is of any use. I have no authority on this topic, but it seems that 21 CFR requirements for corrective action within 30 days refers to the medical physicist tests not the manufacturer's internal requirements.

I will argue that this sort of response from MQSA works against the goals of improving quality and safety in mammographic imaging. None of the things you mentioned is clinically consequential. I understand that Hologic has internal benchmarks based on how they expect their equipment to perform, but a change in HVL of +/- 0.02 mm Al is entirely meaningless in terms of quality or safety, especially given that the measurement error itself may be as high as +/- 10%.

This is a perfect example of where the regulations put in place by MQSA were needed at the time, but this sort of nonsensical "enforcement" is taking time away from focusing on things that actually matter.

Regarding the late note...When Hologic says the "HVL" is out of check, I have found that it almost always means that the mR/mAs is outside of their specifications. As you mentioned, this adjustment affects AEC. I have always just done partial testing afterwards (but in person). (The only time I have ever run into an issue in this scenario is when the FSE accidentally overwrote the HVL data table, which threw off AEC settings.)

I’m interested to hear others’ thoughts.

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> on behalf of Tao, Ashley T via Intl_dxmedphys_wd_osu_list <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>
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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