• DICOM image does not display. "Dicom dataset read failed" error message

    From Howard Mann@21:1/5 to All on Mon Jan 10 12:40:11 2022
    Hi,

    I'm trying to view a .dcm image in Osirix.

    It does not display anything.

    Using Dicom Validator, (in OsiriX) I see the following at the top:

    ___

    (0xe000,0x104f) ? Error - Tag read failed - Implicit VR encoding even though supposed to be explicit
    Error - Dicom dataset read failed

    ___

    Any ideas what this means ?

    Thanks!

    Howard

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  • From Narendra Karanam@21:1/5 to how...@xmission.com on Mon Jan 10 19:43:11 2022
    Change preferred syntax to Implicit Little Endian and again. By default probably Osirix might be expecting Explicit Little Endian VR encoding.

    On Tuesday, January 11, 2022 at 2:10:13 AM UTC+5:30, how...@xmission.com wrote:
    Hi,

    I'm trying to view a .dcm image in Osirix.

    It does not display anything.

    Using Dicom Validator, (in OsiriX) I see the following at the top:

    ___

    (0xe000,0x104f) ? Error - Tag read failed - Implicit VR encoding even though supposed to be explicit
    Error - Dicom dataset read failed

    ___

    Any ideas what this means ?

    Thanks!

    Howard

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Howard Mann@21:1/5 to nar...@gmail.com on Mon Jan 10 20:46:57 2022
    On Monday, January 10, 2022 at 8:43:13 PM UTC-7, nar...@gmail.com wrote:
    Change preferred syntax to Implicit Little Endian and again. By default probably Osirix might be expecting Explicit Little Endian VR encoding.
    ...

    I'm afraid I don't know what you mean by "Change preferred syntax to Implicit Little Endian *and again*"

    When I inspect the metdata of the file and the TransferSyntaxUID Tag, I see: 1.2.840.10008.1.2.2 [BigEndian Explicit]

    A different image file on the same patient has the same Tag value and displays properly.

    Howard

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  • From David Gobbi@21:1/5 to All on Tue Jan 11 15:41:18 2022
    One of the data elements in that particular file might have an incorrect offset (VL) to the next item. I say this because (0xe000,0x104f) is not a valid tag. No tags in the standard start with 0xe000. However, there is a tag ‚Äč(0xfffe, 0xe000) that
    marks the beginning of an encapsulated item (but that might be a red herring).

    The BigEndianExplicit syntax is rare and was retired long ago. Files that use it are either very old, or the files were converted (by accident?) from a different syntax.

    If you know where the files originated (maybe a PACS or another OsiriX?), it might be possible to re-export the files as little endian. Or if somebody sent you these files, politely explain the situation and ask them to re-send.

    And sometimes glitches in the file's structure can be corrected with a hex editor. On macOS I've used xxd on the command-line. Not fun.

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