Usage of Referenced Patient/Visit/Study Sequence after retirement of Study Management Services?

[gunter zeilinger]

Study Management Services were retired by Supplement 98: "Retirement
of Detached, Standalone and other Services", but the attributes

Referenced Patient Sequence (0008,1120)
Referenced Visit Sequence (0008,1125)
Referenced Study Sequence (0008,1110)

are still included in several Information Module Descriptions in DICOM
Part 3 and DICOM Part 4

With the removal of the description of the Study Management Services,
it becomes quite hard for readers without knowledge about the retired
Detached Patient/Visit/Study Management SOP Classes to understand the
description: "Uniquely identifies the Patient/Visit/Study SOP
Instance .." of that attributes in DICOM Part 3 Information Module
tables. Perhaps adding notes like:

"Note: A Detached Patient/Visit/Study Management SOP Class was
defined by previous version of the DICOM Standard, which SOP Instance
(s) could be referenced by item(s) of the Referenced Patient/Visit/
Study Sequence attribute. These have now been retired. New
implementations shall therefore provide an empty Reference Patient/
Visit/Study Sequence attribute, but shall accept non-empty Reference
Patient/Visit/Study Sequence attributes."

would help to clarify past and current usage of such attributes.

I am also afraid that current DICOM Part 17, Annex B "Integration of
Modality Worklist and Modality Performed Procedure Step in the
Original DICOM Standard (Informative)", is rather confusing than
informative for readers without knowledge about the retired Study
Management Services.

I also think, the definition of the usage of Referenced Study Sequence
(0008,1110) in MWL items, MPPS and stored DICOM Composite Objects in
the IHE Radiology Technical Framework, vol II, Appendix A: "Attribute
Consistency between Modality Worklist, Composite IODs, Evidence
Documents, KIN and Modality Performed Procedure Step" should be
updated to reflect the retirement of the Detached Study Management SOP
Class. In particular, I only see little value added by the
introduction of a "Conceptual Study Management entity" referenced by
items in the Referenced Study Sequence from MWL, MPPS and DICOM
Composite Objects:

Even you can declare, that there is always a "Conceptual Study
Management entity", on the contrary that there may no "Requested
Procedure" (=Unscheduled Case), in practice, there is no value for the
Referenced Study Sequence (0008,1110) available for copying from the
MWL item into MPPS and DICOM Composite Objects, if there is no MWL
item. On the other hand, if there is a MWL item, there is always also
a Requested Procedure ID which will/shall be copied into MPPS and
DICOM Composite Objects, which identifies the Requested Procedure
independent if the Modality uses the Study Instance UID from the MWL
item or generates it own - in the case of performing multiple
Scheduled Procedure Steps belonging to different Requested Procedures
in one Performed Procedure Step (=Group Case).

The only advantage of using the Referenced Study Sequence (0008,1110)
in DICOM Composite Objects for referring the same "Conceptual Study
Management entity" as referenced in the MWL items I see is, that the
Referenced Study Sequence (0008,1110) for a particular Study can
already be queried on STUDY level, but the Requested Procedure ID is
only available in the item of the SERIES level attribute Request
Attribute Sequence (0040,0275).

I rather be in doubt, if that justifies the conceptual overhead. In
particular, if(?) common MWL SCP implementations does not provide a
reference to a Detached Study Management SOP Instance in Referenced
Study Sequence (0008,1110).

Any thoughts?

Gunter Zeilinger
Agfa Healthcare Vienna

[David Clunie]

Hi Gunter

Sounds like a good subject for a CP and an interesting WG 6
discussion, particularly if you can supply alternative text to put in
the standard.

Perhaps you could write it and get Rob Horn to submit it ?

David

[Markus Sabin]

As I understand the IHE-RAD-TF, the Referenced Study- and Patient Sequence attributes are "R+" attributes. The SCU is obliged to request for them. I wonder why they have been explicitly made mandatory in IHE although they refer to retired SOP Classes in DICOM.

Or am I misunderstanding the IHE-TF here?