[Insight-users] Re: Bug 1056

[Dr. Uwe Köhler]

Dear Luis,

many thanks for the quick help. I updated the DICOMAppHelper.cxx only in 
Version 1.8.1 and I do get different values for the pixel spacing in x- and 
y-direction now. However, after a discussion with the manufacturer of the 
MR-Scanner (Bruker) and after checking the standard (my quote below is taken 
directly from the DICOM standard document), I am convinced it is Row-spacing 
(spacing in Y (PixelSpacing[1])) first. Nothing much about DICOM can supprise 
me anymore ...

I was convinced of the opposite, like you, before talking to Bruker (and 
checking the standard ;-). Bruker also mentioned that almost nobody uses 
non-isotrope in-plane pixels. Well, we do and you are almost there.

Many thanks again

Uwe

Am Dienstag, 14. Dezember 2004 23:58 schrieben Sie:
> Hi Uwe,
>
> Thanks a lot for your detailed message and for editing
> the bug in the database.
>
> Following your hints, we just added an extra step to the
> parsing in order to recover the second number in the
> tag 0028x0030.  We are now searching for the separator
> and taking the second part of the string.
>
> This has been committed to CVS so you can give it a try.
>
> We are still unclear regarding the order of the spacing.
> That is, whether the first value is suppossed to be the
> spacing in X (PixelSpacing[0]) or the spacing in Y
> (PixelSpacingg[1])
>
>
> If you have a chance, please give it a try at the CVS
> version and let us konw what you find.
>
>
>     Thanks
>
>
>
>        Luis
>
>
>
>
> -------------------------
>
> Dr. Uwe Köhler wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> >
> > Dear Luis,
> >
> > I tried to post a comment to the bug, but the system forgot most of it:
> >
> > I have images with non-isotropic in-plane resolution and ITK cannot
> > interpret the pixel spacing. According to the DICOM standard you do get
> > the ROW spacing first and then the COL spacing.
> >
> > - From the standard:
> > Physical distance in the patient between the center of each pixel,
> > specified by a numeric pair - adjacent row spacing (delimiter) adjacent
> > column spacing in mm.
> >
> > I also seem to get rounding errors, however I can live with those. I just
> > cannot fix the DICOM code
> >   if (len > 0)
> >     {
> >     fval = DICOMFile::ReturnAsFloat(val,
> > parser->GetDICOMFile()->GetPlatformIsBigEndian());
> >     }
> >
> >   if (group == 0x0028 && element == 0x0030)
> >     {
> >     this->PixelSpacing[0] = this->PixelSpacing[1] = fval;
> >     }
> >   else if (group == 0x0018 && element == 0x0050)
> >     {
> >     this->PixelSpacing[2] = fval;
> >     }
> >
> > since val should have more than one value. Could you fix that?
> >
> > Cheers
> >
> > Uwe
> > - --

-- 
 |                                                                 |
-+-----------------------------------------------------------------+-
 |  Dr. Uwe Köhler              MR - Physics                       | 
 |                              German Heart Institute Berlin      |
 |                              Augustenburger Platz 1             |
 |                              D - 13353 Berlin                   |
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