CR Images in DICOM files from differenet Machines - DICOM

This is a discussion on CR Images in DICOM files from differenet Machines - DICOM ; In what way does the CR Images stored in DCM files generated by machine to machine differ say one from Siemens and other from GE machine. What parameters of the DCM can be used for standarization among the images....

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Thread: CR Images in DICOM files from differenet Machines

  1. CR Images in DICOM files from differenet Machines

    In what way does the CR Images stored in DCM files generated by
    machine to machine differ say one from Siemens and other from GE
    machine. What parameters of the DCM can be used for standarization
    among the images.


  2. Re: CR Images in DICOM files from differenet Machines

    Not sure which you mean for GE. They have some DX machines but at one
    point GE was also rebranding Agfa ADC CR.

    My experience has been with Philips Thoravision, GE xqi, Agfa
    ADC/Solo, Fuji 5000, Lumisys CR, various Kodak models, & Hologic.

    Philips, GE, and Hologic machines are actually DR not CR. GE and
    hologic can produce either CR or DX images as a configuration setting.
    Not sure that this is still too valid as fuji now makes their own
    workstation rather than having Dejarnette make theirs but primary
    "image difference" experience we had with mixed CR/DR vendors was with
    sites where Dejarnette QC workstation was deployed on Fuji 5000 CRs.
    The Dejarnette workstation created all the images in a single study as
    multiple images in one Series. In hospitals with a mix of different
    vendor CRs we ran into issues because some other vendors organize the
    images with one image per series. I believe most vendors are now doing
    it one image per series but you may find some that do it the other way.
    Main point where this would come into play was with hanging protocols
    in the PACS/workstations. You normally try to set up a hanging protocol
    by the Study Description, Procedure Code, Requested procedure, etc. The
    procedure defines requirements for how you want the image laid out on
    the monitors. The actual implementation/configuration of the hanging
    protocol uses an algorithm to pick up some DICOM structural elements of
    the studies and use it to assign different parts of the study to
    different monitors or areas of the monitor. It gets more complicated
    when studies of the same requested procedure can have very different
    organization of the images in the study- such as one series/multiple
    images and multiple series/one image each.

    Other areas where imags from different manufactures differed - some
    manufactures include non-linear VOI LUTs in the images whereas others
    apply their private algorithms changing contrast levels into the image
    pixels themselves. Some display software won't handle the VOI LUTs or
    the workstation behavior changes depending on whether there is a VOI
    LUT included in the image.

    Mentioned above but should probably be called out - some vendors
    support either CR or DX SOP class for their output image format. . Not
    PACS or display workstations will support DX images. GE xqi
    dynamically negotiates, sending a CR if the destination machine won't
    accept DX. The GE will also send For Processing as well as For
    Presentation images unless configured not to.

    The experiece above was spread over a 7-8 year period in which new
    products came on to the market and new developments in the standard
    clarified and changed things. For CR's especially it is not uncommon
    for a relatively old device to still be in operation alongside newer
    devices where DICOM clarified its stance on some issue. The
    series/image organization is a case in point. Another area I've seen
    some movement in is in the attributes used to document the pixel size
    and orientation of the image relative to the patient. My point here is
    that the differences between the images are not just between
    manufactures. It is also across the age of particular manufacture
    device. When comparing different manufactures images, need to take into
    account a difference in dicom encodings might not be that different if
    both machines were being purchased right now

    Hope this helped - maybe you could clarify by what you mean when you
    say you're looking for "standardization among images". Standardization
    in what sense? Window/Level values? Hanging Protocols? Anatomic codes,
    etc?


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