[Intl_DxMedPhys] Siemens CTDI Tool & Flash Protocol Questions

[Dale Schippers]

For custom CTDI tool, you can set the DFOV in your helical protocol (e.g.,
35cm for body scans), before saving it as ctdi_body. Custom CTDI tool will
convert the helical protocol to axial with the same DFOV (35cm) and mAs
corrected for pitch.

With service window open (close CTDI measurement window), you can open the
patient browser, look for service patient, and drag the series from Service
patient to your ACR phantom patient-> ACR phantom study. You can also
change the series description on Siemens Acquisition workstation, e.g.,
from "rot" to "CTDI Adult Abd”. Patient: Service Patient, Study: Customer
CTDI. To make it easier to drag images from the service patient into your
ACR patient, you can Mark the 2 studies and Filter by Marked and then drag
and drop.

On Thu, Jan 30, 2025 at 11:06 PM Daniel Vergara via
Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list at lists.osu.edu> wrote:

> Hi Gretchen, While using service tool, go to the patient browser and
> search for service patient. The images are in there and an available only
> while the tool is open. Siemens uses flying focal spot in these scanners,
> probably the SOMATOM drive
> Hi Gretchen,
>
> While using service tool, go to the patient browser and search for service
> patient. The images are in there and an available only while the tool is
> open.
>
> Siemens uses flying focal spot in these scanners, probably the SOMATOM
> drive too. The beam width is actually half of the full coverage per
> rotation under this mode. So make sure you take half of the displayed nT to
> compute the CTDI100. If you already did that or this system doesn’t perform
> flying focal spot, then another thing to consider is checking what your
> meter’s delay time is set to. With a dual scan, it is possible that the
> meter was delayed during the second scan and missed it. I had that
> experience and changing the delay time on the meter (in my case Piranha) to
> 100ms, it caught the two exposures but as two separate measurements.
>
> Thank you,
> Daniel Vergara
>
> On Jan 30, 2025, at 1:07 PM, Gretchen Raterman Bell via
> Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list at lists.osu.edu>
> wrote:
>
> 
> Hi, group!  I had to type in a new name for the list! I was wondering if
> anyone has successfully grabbed the images produced (or not produced?) when
> using the CTDI Tool on Siemens.   My group covers a site that isn't ACR
> accredited yet for
> Hi, group!  I had to type in a new name for the list!
>
> I was wondering if anyone has successfully grabbed the images produced (or
> not produced?) when using the CTDI Tool on Siemens.  My group covers a site
> that isn't ACR accredited yet for pediatrics, but I believe they will at
> some point.
>
> In addition, we have another site with a Somatom Drive (dual energy, two
> tubes) that has the capability of acquiring with what's called Flash mode.
> I believe the unit is using both tubes to be able to up the pitch, which is
> 3 in some of the protocols developed at the site with apps.  When I used
> the CTDI tool on their Flash Ped Abd protocol, the expected mA displayed in
> QA->CTDITOOL program came in at about half of what I'd calculate using the
> eff mAs, t/rot, pitch.  I'm assuming this is because there's two tubes??
> Does anyone have any good reading material on how exactly these Flash
> protocols work?  I'd like to understand it better.
>
> Thanks as always,n R. Bell, M.S., DABR
> Diagnostic Imaging Physicist
> Ochsner Medical Center
> (504)842-8506
>
>
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