[Intl_DxMedPhys] 3T vs 5T siting considerations

Fri May 16 16:53:48 EDT 2025

Hi Nima,

Your initial list of bullet points are all very good questions. I'll add my
thoughts to each one

   - Scanner weight: this would be high on my list of concerns for the 5T,
   especially if there will be floors below you. You should be able to get
   that information from United Imaging, as I would think that would be the
   most difficult to address/account for later after other systems are
   installed and up/running.
   - In some respects, being at a different field should be easier to site
   compared to the same field strength. I have heard anecdotes of cross-talk
   issues in equipment rooms with installing two MRI's at the same field
   strength ide by side. I think the vendor will end up ramping the systems to
   slightly different field strengths to obviate the problem
   - Perpendicular installation & concerns about stray field: I suspect
   that you will need magnetic shielding (i.e. steel walls) to deal with some
   of these issues. Often, this cannot be determined without involving the
   vendor. Assuming you buy the six 3Ts from the same one, you should be able
   to lean on them to scope out another 3T in the "shell" space and determine
   what mitigations might be necessary in the future. I have had two installs
   where we had to add steel in rear walls to prevent the 5 Gauss lines from
   straying into patient areas or non-Zone IV hallways. One advantage that you
   do have now -- 9 Gauss is the new standard for restriction based on recent
   changes. (Check ACR Manual on MR Safety for complete description.) BTW: I
   would suspect a 5T to require a larger size room or magnetic shielding
   compared to a 3T, but that may be vendor dependent.
   - 5T vs 3T Concerns
      - Power supply requirements. I suspect 5T RF amp would require more
      power.
      - Chiller specs: similar to above -- cooling requirements may be
      larger
      - size of equipment room: Assuming different vendors, you may have to
      account for a bigger footprint.
      - Clinically, I would be worried about clearing any medical devices;
      as you will be off-label for almost all MR Conditional devices. I would
      also see if ancillary equipment (physiological monitoring, etc...) is
      available for >3T. (Hope that it would be but it's not something I have
      ever had to worry about.) Coil availability for peds can also
sometimes be
      a concern for new systems.

Good luck. Sounds like a fun project -- my head would be spinning at the
prospect of six new systems.

Best, Steve

Steven Shea, PhD
Associate Professor, MR Scientist
Department of Radiology & Medical Imaging. Loyola Medicine

On Sat, May 3, 2025 at 11:01 AM <
intl_dxmedphys_wd_osu_list-request at lists.osu.edu> wrote:

> ---------- Forwarded message ----------
> From: Nima Kasraie <Nima.Kasraie at utsouthwestern.edu>
> To: "intl_dxmedphys_wd_osu_list at lists.osu.edu" <
> intl_dxmedphys_wd_osu_list at lists.osu.edu>
> Cc:
> Bcc:
> Date: Fri, 2 May 2025 17:23:18 +0000
> Subject: [Intl_DxMedPhys] 3T vs 5T siting considerations
> Hello group, Below is a rough schematic showing part of an area in our new
> peds hospital where the MR suites will be installed in a few years. All 6
> magnets except for one will be 3T. There will be 3 more down the hall. 9 in
> total. However there
>
> Hello group,
>
>
>
> Below is a rough schematic showing part of an area in our new peds
> hospital where the MR suites will be installed in a few years. All 6
> magnets except for one will be 3T. There will be 3 more down the hall. 9 in
> total.
>
>
>
> However there is chatter among the leadership that they may swap out one
> of the 3Ts for a 5T. Specifically this model
> <https://urldefense.com/v3/__https://usa.united-imaging.com/products/magnetic-resonance/umr-jupiter-5t__;!!KGKeukY!1y_qhnMVgMiaNFbSsAudf_vqf_62j6S9rjDZjVASt5_Q0MbwmMw2jiuI6KklTA7XsVC7rk8hD-Q9MkVB2m4KG3TvWXVl6FLMf9172uOH5QQMb69c8LBUKg$>.
> Either initially or maybe down the line.
>
>
>
> So I’m wondering: as far as * siting considerations*, would there be any
> issues I need to look into?  The UI-5T and Siemens 3T scanners seem to be
> the same size (according to their brochure).
>
>
>
> But what about:
>
>
>
>    - Scanner weight? Is it heavier? Does the floor need to be reinforced
>    for a 5T swap?
>    - Will putting a 5T in the middle of a bunch of 3Ts warrant any
>    special considerations? Especially since I think one of the scanners
>    actually might be at 90 degrees rotated.
>    - Any special shimming issues? Especially since they might be
>    different vendors (all 3Ts will be Siemens)
>    - Sensitivity, potential vibration, artifacts, etc? I don’t expect the
>    gauss lines of a 5T to shift considerably from a 3T. But I may be wrong on
>    this?
>    - Any other questions I need to be asking? I’ve never seen a >3T
>    magnet in a clinic. Just trying to predict what questions I may be getting
>    and what things I need to look into.
>
>
>
>
>
>
>
>
>
>
>
> Do any of y’all actually have a 5T? Would appreciate any experiences you
> might wanna share.
>
>
>
>
>
> Much obliged.
>
>
>
>
>
> Nima
>
>
>
>
>
>
>
>
>
>
>
> *Nima Kasraie, PhD, MSc, DABR (D), DABSNM (I)*
>
> Associate Professor of Radiology
>
> Medical Physics Division
>
>
>
> Department of Radiology
>
> 5323 Harry Hines Blvd., Dallas, Texas 75390-9071
>
> Phone: 214-648-7978
>
> https://urldefense.com/v3/__http://www.utsouthwestern.edu/radiology__;!!KGKeukY!xQFH9q3wN4e-OO6wQzbzAHHGZnu2Ldf_vjYytzZwaVKOE9mLrY-sM3Jtb5BoTqpB5wqfrq_zWUrkH0NYtjQM5zYGI4EbQP5l2O_6M4-aCNjDaq1i$ 
> <https://urldefense.com/v3/__http://www.utsouthwestern.edu/radiology__;!!KGKeukY!1y_qhnMVgMiaNFbSsAudf_vqf_62j6S9rjDZjVASt5_Q0MbwmMw2jiuI6KklTA7XsVC7rk8hD-Q9MkVB2m4KG3TvWXVl6FLMf9172uOH5QQMb686ZKqSSg$>
>
>
>
>
>
> ------------------------------
>
> UT Southwestern
>
> Medical Center
>
> The future of medicine, today.
>
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