MPPS Relationship - Referenced Study Sequence attribute BUG - DICOM

This is a discussion on MPPS Relationship - Referenced Study Sequence attribute BUG - DICOM ; I'm trying to implement a MPPS server, so i'm studying the attributes of the MPPS SOP so i can find what i need to support and how the data representation will be, i already implemented a MWL SCU and now ...

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Thread: MPPS Relationship - Referenced Study Sequence attribute BUG

  1. MPPS Relationship - Referenced Study Sequence attribute BUG

    I'm trying to implement a MPPS server, so i'm studying the attributes
    of the MPPS SOP so i can find what i need to support and how the data
    representation will be, i already implemented a MWL SCU and now i'm
    trying to integrate between the two SOPs.

    The problem is with the Referenced Study Sequence (0008,1110) under the
    Performed Procedure Step Relationship Module, the standard says in PS
    3.3 Table C.4-13 that this sequence shall have only one item, but when
    you search on how the standard and the IHE tells you to fill this
    sequence you find that you should copy its value from the Requested
    Procedure Module in the MWL SOP, but this sequence there is mlti-item
    so how can this be?

    refer to DICOM PS 3.17 section J.4.1


  2. Re: MPPS Relationship - Referenced Study Sequence attribute BUG


    Hercules Dev. wrote:
    > I'm trying to implement a MPPS server, so i'm studying the attributes
    > of the MPPS SOP so i can find what i need to support and how the data
    > representation will be, i already implemented a MWL SCU and now i'm
    > trying to integrate between the two SOPs.
    >
    > The problem is with the Referenced Study Sequence (0008,1110) under the
    > Performed Procedure Step Relationship Module, the standard says in PS
    > 3.3 Table C.4-13 that this sequence shall have only one item, but when
    > you search on how the standard and the IHE tells you to fill this
    > sequence you find that you should copy its value from the Requested
    > Procedure Module in the MWL SOP, but this sequence there is mlti-item
    > so how can this be?
    >
    > refer to DICOM PS 3.17 section J.4.1


    seems my question is not so clear, ok here it is again in a simple way:
    Is the Referenced Study Sequence (0008,1110) under the Performed
    Procedure Step Relationship Module a single item sequence or a
    multi-item sequence?

    Now, if it's a single item sequence how the SCU will send it to me in
    the MPPS N-CREATE if the Requested Procedure has multi item in its
    Referenced Study Sequence (0008,1110) ?

    and if it is multi-item then why the DICOM standard says its a single
    item in PS 3.3 Table C.4-13 ?

    All references to the DICOM or IHE are from the latest version.

    Thanks
    Zaid H. Safadi


  3. Re: MPPS Relationship - Referenced Study Sequence attribute BUG

    So does this mean that no body know the answer or that it's a very
    straight forward and trivial??!!!

    Hercules Dev. wrote:
    > Hercules Dev. wrote:
    > > I'm trying to implement a MPPS server, so i'm studying the attributes
    > > of the MPPS SOP so i can find what i need to support and how the data
    > > representation will be, i already implemented a MWL SCU and now i'm
    > > trying to integrate between the two SOPs.
    > >
    > > The problem is with the Referenced Study Sequence (0008,1110) under the
    > > Performed Procedure Step Relationship Module, the standard says in PS
    > > 3.3 Table C.4-13 that this sequence shall have only one item, but when
    > > you search on how the standard and the IHE tells you to fill this
    > > sequence you find that you should copy its value from the Requested
    > > Procedure Module in the MWL SOP, but this sequence there is mlti-item
    > > so how can this be?
    > >
    > > refer to DICOM PS 3.17 section J.4.1

    >
    > seems my question is not so clear, ok here it is again in a simple way:
    > Is the Referenced Study Sequence (0008,1110) under the Performed
    > Procedure Step Relationship Module a single item sequence or a
    > multi-item sequence?
    >
    > Now, if it's a single item sequence how the SCU will send it to me in
    > the MPPS N-CREATE if the Requested Procedure has multi item in its
    > Referenced Study Sequence (0008,1110) ?
    >
    > and if it is multi-item then why the DICOM standard says its a single
    > item in PS 3.3 Table C.4-13 ?
    >
    > All references to the DICOM or IHE are from the latest version.
    >
    > Thanks
    > Zaid H. Safadi



  4. Re: MPPS Relationship - Referenced Study Sequence attribute BUG

    Hi Zaid

    The bottom line is that since the cardinality of Referenced
    Study Sequence in the MPPS definition is limited to no more
    than one, you cannot ever send more than one; so you
    have to decide which one to send if there is a choice,
    or find another way.

    Since the Referenced Study Sequence occurs inside an item
    of the Scheduled Step Attributes Sequence, which may have
    multiple items, the problem only occurs when the scheduled
    step in the MWL contains multiple items in Referenced Study
    Sequence, and not when one PPS is being performed to satisfy
    multiple SPS, because in that case there would be more than
    one Scheduled Step Attributes Sequence, each still containing
    a Referenced Study Sequence with a single item.

    As far as IHE is concerned, in the Query Modality Worklist
    transaction, it specifies that "the Referenced Study Sequence
    shall contain only one Referenced SOP Class UID and one
    Referenced SOP Instance UID for each Scheduled Procedure
    Step" (see IHE Rad TF Vol 2 4.5.4.1.2.2), so there is only
    going to be one item to copy (regardless of what DICOM
    permits).

    So your own MWL implementation should probably enforce this
    IHE restriction.

    If you encounter another MWL implementation, and it is not
    IHE compliant in this respect, then you will have to make
    a choice, or send multiple Scheduled Step Attributes Sequence
    items that are identical apart from different Referenced Study
    Sequence entries (not sure if that is such a cool idea either).

    But you should NEVER send more than one item in the Referenced
    Study Sequence inside the Scheduled Step Attributes Sequence,
    since that is explicitly forbidden (I don't recall why it
    was decided that it be this way).

    David

    Hercules Dev. wrote:
    > Hercules Dev. wrote:
    >> I'm trying to implement a MPPS server, so i'm studying the attributes
    >> of the MPPS SOP so i can find what i need to support and how the data
    >> representation will be, i already implemented a MWL SCU and now i'm
    >> trying to integrate between the two SOPs.
    >>
    >> The problem is with the Referenced Study Sequence (0008,1110) under the
    >> Performed Procedure Step Relationship Module, the standard says in PS
    >> 3.3 Table C.4-13 that this sequence shall have only one item, but when
    >> you search on how the standard and the IHE tells you to fill this
    >> sequence you find that you should copy its value from the Requested
    >> Procedure Module in the MWL SOP, but this sequence there is mlti-item
    >> so how can this be?
    >>
    >> refer to DICOM PS 3.17 section J.4.1

    >
    > seems my question is not so clear, ok here it is again in a simple way:
    > Is the Referenced Study Sequence (0008,1110) under the Performed
    > Procedure Step Relationship Module a single item sequence or a
    > multi-item sequence?
    >
    > Now, if it's a single item sequence how the SCU will send it to me in
    > the MPPS N-CREATE if the Requested Procedure has multi item in its
    > Referenced Study Sequence (0008,1110) ?
    >
    > and if it is multi-item then why the DICOM standard says its a single
    > item in PS 3.3 Table C.4-13 ?
    >
    > All references to the DICOM or IHE are from the latest version.
    >
    > Thanks
    > Zaid H. Safadi
    >


  5. Re: MPPS Relationship - Referenced Study Sequence attribute BUG

    Thanks MR. Cluni for your reply to my question, and from your answer I
    figured that it was a valid and important question.

    So there is no way to send this sequence as a multi-item, and it should
    always be sent with one referenced study, so if a multi item referenced
    study sequence exist in a work-list either the SCU select one of them
    or send each item in a different Scheduled Step Attribute Sequence item
    with same SPS information.

    So in the case of a MPPS SCP, it should not accept a Referenced Study
    Sequence with multi-item, even though it can perform matching for this
    sequence with the original MWL Referenced Study Sequence ( in case the
    MPPS and MWL SCPs uses the same data store).

    As for my implementing a MPPS SCP is it legal if I relaxed this rule
    and ignored the fact that I received this sequence as multi-item
    especially that I won't store it and only will be used for matching?

    And if there is a necessity for a MPPS SCU to send this sequence as a
    multi-item -which is the logical behavior in our case- why the standard
    don't allow this sequence to be multi-item?

    Thanks,
    Zaid H. Safadi

    David Clunie wrote:
    > Hi Zaid
    >
    > The bottom line is that since the cardinality of Referenced
    > Study Sequence in the MPPS definition is limited to no more
    > than one, you cannot ever send more than one; so you
    > have to decide which one to send if there is a choice,
    > or find another way.
    >
    > Since the Referenced Study Sequence occurs inside an item
    > of the Scheduled Step Attributes Sequence, which may have
    > multiple items, the problem only occurs when the scheduled
    > step in the MWL contains multiple items in Referenced Study
    > Sequence, and not when one PPS is being performed to satisfy
    > multiple SPS, because in that case there would be more than
    > one Scheduled Step Attributes Sequence, each still containing
    > a Referenced Study Sequence with a single item.
    >
    > As far as IHE is concerned, in the Query Modality Worklist
    > transaction, it specifies that "the Referenced Study Sequence
    > shall contain only one Referenced SOP Class UID and one
    > Referenced SOP Instance UID for each Scheduled Procedure
    > Step" (see IHE Rad TF Vol 2 4.5.4.1.2.2), so there is only
    > going to be one item to copy (regardless of what DICOM
    > permits).
    >
    > So your own MWL implementation should probably enforce this
    > IHE restriction.
    >
    > If you encounter another MWL implementation, and it is not
    > IHE compliant in this respect, then you will have to make
    > a choice, or send multiple Scheduled Step Attributes Sequence
    > items that are identical apart from different Referenced Study
    > Sequence entries (not sure if that is such a cool idea either).
    >
    > But you should NEVER send more than one item in the Referenced
    > Study Sequence inside the Scheduled Step Attributes Sequence,
    > since that is explicitly forbidden (I don't recall why it
    > was decided that it be this way).
    >
    > David
    >
    > Hercules Dev. wrote:
    > > Hercules Dev. wrote:
    > >> I'm trying to implement a MPPS server, so i'm studying the attributes
    > >> of the MPPS SOP so i can find what i need to support and how the data
    > >> representation will be, i already implemented a MWL SCU and now i'm
    > >> trying to integrate between the two SOPs.
    > >>
    > >> The problem is with the Referenced Study Sequence (0008,1110) under the
    > >> Performed Procedure Step Relationship Module, the standard says in PS
    > >> 3.3 Table C.4-13 that this sequence shall have only one item, but when
    > >> you search on how the standard and the IHE tells you to fill this
    > >> sequence you find that you should copy its value from the Requested
    > >> Procedure Module in the MWL SOP, but this sequence there is mlti-item
    > >> so how can this be?
    > >>
    > >> refer to DICOM PS 3.17 section J.4.1

    > >
    > > seems my question is not so clear, ok here it is again in a simple way:
    > > Is the Referenced Study Sequence (0008,1110) under the Performed
    > > Procedure Step Relationship Module a single item sequence or a
    > > multi-item sequence?
    > >
    > > Now, if it's a single item sequence how the SCU will send it to me in
    > > the MPPS N-CREATE if the Requested Procedure has multi item in its
    > > Referenced Study Sequence (0008,1110) ?
    > >
    > > and if it is multi-item then why the DICOM standard says its a single
    > > item in PS 3.3 Table C.4-13 ?
    > >
    > > All references to the DICOM or IHE are from the latest version.
    > >
    > > Thanks
    > > Zaid H. Safadi
    > >



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