[Insight-users] Wrong reading of spacing in "z" axis by GE low-dose CT?

[Mathieu Malaterre]

FYI have a look at:

https://sourceforge.net/apps/mediawiki/gdcm/index.php?title=Using_GDCM_API#Where_is_the_value_of_gdcm.Image.Spacing_coming_from_.3F

Slice Thickness does not means physical spacing, where did you read
that ? It means the tickness of slice during acquisition time. I know
some broken DICOM implementation uses it but this is is incorrect.

On Wed, Apr 13, 2011 at 2:50 PM, Bc. Michal Srna <michal at srna.info> wrote:
> Hello GDCM/ITK developers,
>
> I just discovered, that ITKv4 (also ITK 3.20) reads probably wrong value of
> DICOM tag "0018,050 Slice Thickness" from low-dose CT data provided by
> SPECT/low-doseCT multimodal imaging system (manufacturer GE, model INFINIA)
> .
>
> If I am not wrong - when reading CT data ITK takes as value of spacing in
> "z" axis value from tag "0018,050 Slice Thickness". In my original low-dose
> CT data it is set to 6.1, but ITK reads spacing in "z" as 4.41962 and when I
> save those data via ITK, it writes that incorrect value into that tag
> "0018,050 Slice Thickness" and also into tag "0018,088 Spacing between
> Slices".
>
> So I am asking, if it's not bug, where does ITK take that value 4.41962,
> when "0018,050 Slice Thickness" in original data is 6.1?
>
> If it could help developers, I can provide example of those data, which are
> affected by this problem.
>
> Thanks for help!
>
> --
> S pozdravem Bc. Michal Srna
>
> Fotografické portfolio:
> http://michalsrna.cz
>
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-- 
Mathieu