private dicom tag, how to obtain its value

[Frank Rogge]

Hello,

For the digital mammo system from Sectra, a floating point number
PixelToPhotonRatio stored in a private DICOM tag 0019:1024 (type FD) is
required for linearisation of the image.
Does anybody has experience how to obtain this number in an easy way?
ImageJ doesn't know the tag definition (it's private) and interpretes
the value as a string: << ºEt{?®Ö? >> instead of a number:
0.354404802857143.

Thanks,

Frank Rogge

[Johannes Hermen]

> For the digital mammo system from Sectra, a floating point number
> PixelToPhotonRatio stored in a private DICOM tag 0019:1024 (type FD) is
> required for linearisation of the image.
> Does anybody has experience how to obtain this number in an easy way?

It should work with our DICOM Tools (ImageJ Plugins/Viewer)
http://santec.tudor.lu/project/optimage/dicom/start
Just open the Image with the DicomViewer an press  View Header

If you need the Tag in your own App. you can just do

new DicomHeader(file).getHeaderTag("0019:1024");

If it does not work, could you please send me one of the images to
implement it.


Greets
      Johannes


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[Wayne Rasband]

> Hello,
>
> For the digital mammo system from Sectra, a floating point number
> PixelToPhotonRatio stored in a private DICOM tag 0019:1024 (type FD)
> is required for linearisation of the image.
> Does anybody has experience how to obtain this number in an easy way?
> ImageJ doesn't know the tag definition (it's private) and interpretes
> the value as a string: << ºEt{?®Ö? >> instead of a number:
> 0.354404802857143.

You need to upgrade to the ImageJ 1.42m daily build, which fixes a bug
that caused FD tags to not be decoded correctly. You also need to
download the DICOM dictionary at

     http://rsb.info.nih.gov/ij/download/docs/DICOM_Dictionary.txt

to the ImageJ folder, add this line

00191024=FDPixel to Photon Ratio

and restart ImageJ.

-wayne

[Frank Rogge]

Thanks for the solution. It works perfect. I was able to simply build my
linearisation plugin based on this pixeltophotonratio.

Frank

Wayne Rasband schreef:

>> Hello,
>>
>> For the digital mammo system from Sectra, a floating point number
>> PixelToPhotonRatio stored in a private DICOM tag 0019:1024 (type FD)
>> is required for linearisation of the image.
>> Does anybody has experience how to obtain this number in an easy way?
>> ImageJ doesn't know the tag definition (it's private) and interpretes
>> the value as a string: << ºEt{?®Ö? >> instead of a number:
>> 0.354404802857143.
>
> You need to upgrade to the ImageJ 1.42m daily build, which fixes a bug
> that caused FD tags to not be decoded correctly. You also need to
> download the DICOM dictionary at
>
>     http://rsb.info.nih.gov/ij/download/docs/DICOM_Dictionary.txt
>
> to the ImageJ folder, add this line
>
> 00191024=FDPixel to Photon Ratio
>
> and restart ImageJ.
>
> -wayne
>
>