[Intl_DxMedPhys] MRI Question about declining Tx

[Travis White]

I had a similar (but reversed) encounter on a Philips 3T unit last fall.  Service blamed it on the outside temperature (April-August).  I haven’t put much more thought into the potential mechanism.

[cid:image004.png at 01DC911C.550EB010]

From: Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces+travis.white=prismahealth.org at lists.osu.edu> On Behalf Of Hardy, Peter A. via Intl_dxmedphys_wd_osu_list
Sent: Thursday, January 29, 2026 12:29 PM
To: DxMedPhys List <intl_dxmedphys_wd_osu_list at lists.osu.edu>
Subject: [Intl_DxMedPhys] MRI Question about declining Tx

Hi I have a site where the transmit voltage on the head coil has been in steady decline over past few months. The site is one of three mobile units we have. Charts of Tx voltage vs date for the unit in question and two other mobile units are
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Hi I have a site where the transmit voltage on the head coil has been in steady decline over past few months. The site is one of three mobile units we have. Charts of Tx voltage vs date for the unit in question and two other mobile units are
Hi

I have a site where the transmit voltage on the head coil has been in steady decline over past few months. The site is one of three mobile units we have. Charts of Tx voltage vs date for the unit in question and two other mobile units are shown below. The 2nd and 3rd units do not show this behavior. I can understand an increase in Tx over time as a consequence of a gradual failure of a component in the head coil requiring increased Tx gain to overcome the situation. A decrease in Tx seems odd.
[cid:image005.png at 01DC911C.550EB010]
[cid:image006.png at 01DC911C.550EB010]
[cid:image007.png at 01DC911C.550EB010]
Any suggestions of what could be going on here?


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>

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