[Intl_DxMedPhys] [EXTERNAL] Question for DXA experts

[Kyle Ewert]

Hi,

Just reading through recent-old listserv posts and saw this.

I have a Hologic DXA scanner and noted the same yearly cycle – it was also inversely correlated to outdoor temperature. I had our radiographers start logging indoor temperature and found that indoor temperature itself was inversely correlated to outdoor temperature, with QC failures beginning in mid-May when the heating would start cycling.

Mornings were worse, as the doors were shut overnight and heat would build up in the room. Afternoon QC done as a comparison point was passing, and the indoor temperatures were more reasonable.

Kyle Ewert

Medical Physicist - Alfred Health Radiology
P   03 9076 2778        |     E   k.ewert at alfred.org.au<mailto:k.ewert at alfred.org.au>


From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces+k.ewert=alfred.org.au at lists.osu.edu> On Behalf Of Bob Kobistek via Intl_dxmedphys_wd_osu_list
Sent: Thursday, 5 February 2026 11:39 PM
To: High, Maynard <Maynard.High at wmchealth.org>; DxMedPhys List <intl_dxmedphys_wd_osu_list at lists.osu.edu>
Subject: Re: [Intl_DxMedPhys] [EXTERNAL] Question for DXA experts

After reading others’ posts who replied off list, I’m leaning in that direction. The low points of the sine wave occur in approximately September, and the peaks in approximately March. This inversely corresponds to the annual outdoor temperature

After reading others’ posts who replied off list, I’m leaning in that direction. The low points of the sine wave occur in approximately September, and the peaks in approximately March. This inversely corresponds to the annual outdoor temperature
After reading others’ posts who replied off list, I’m leaning in that direction. The low points of the sine wave occur in approximately September, and the peaks in approximately March. This inversely corresponds to the annual outdoor temperature cycle, but why would the outdoor temperature have any effect on a scanner in a temperature-controlled environment? So thanks to everyone who responded. I’m going to talk to the FE and building maintenance and see if we can figure this out.




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

From: High, Maynard <Maynard.High at wmchealth.org<mailto:Maynard.High at wmchealth.org>>
Sent: Wednesday, February 4, 2026 3:40 PM
To: DxMedPhys List <intl_dxmedphys_wd_osu_list at lists.osu.edu<mailto:intl_dxmedphys_wd_osu_list at lists.osu.edu>>; Bob Kobistek <bob at rjkmedphys.com<mailto:bob at rjkmedphys.com>>
Subject: Re: [EXTERNAL] [Intl_DxMedPhys] Question for DXA experts

Looks like my ConEd electric bill.  Could it have anything to do with mean voltage cycling thru the seasons?

Maynard High
Medical Physics: Westchester Medical Center - NYMC
914-493-1410
maynard.high at wmchealth.org<mailto:maynard.high at wmchealth.org>
________________________________
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 Bob Kobistek 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: Wednesday, February 4, 2026 3:08 PM
To: DxMedPhys List <intl_dxmedphys_wd_osu_list at lists.osu.edu<mailto:intl_dxmedphys_wd_osu_list at lists.osu.edu>>
Subject: [EXTERNAL] [Intl_DxMedPhys] Question for DXA experts

Check out these daily QC charts. Interesting? Robert J. Kobistek, MS, FACR, DABR, MRSE(MRSC™) Medical Physicist RJK Medical Physics, Inc. 440-463-7879 ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍ ‍

Check out these daily QC charts. Interesting?



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

Medical Physicist

RJK Medical Physics, Inc.

440-463-7879

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