In most of our PACS installations in Europe (mainly Germany), we have
to meet the user requirement, to document the Requesting Physican or
(even more often) the Requesting Service of a Requested Procedure with
the archived Studies, including the possibility to use these attributes
as matching keys in queries.

But DICOM only specifies Accession Number and Referring Physican Name
as mandatory request attributes in Composite Object IODs and as
matching keys for DICOM Query on STUDY level, and IHE extend that
(only) by declaring support of

>Requested Procedure ID

and
>Scheduled Procedure Step ID

nested in the Request Attribute Sequence

as matching key on SERIES level as mandatory.

One workaround - beside using a proprietary query against the PACS DB -
is to provide the Requesting Physican or the Requesting Service as
Referring Physician Name by the Modality Worklist.

Another, more sophisticated, workaround is to copy Requesting Physican
and Requesting Service provided by the Modality Worklist into the item
of the Request Attribute Sequence of the Composite Object, when
receiving it from the modality, and to extend the Query SCP to support
also matching on these nested attributes on SERIES level. Such solution
can als handle the case, if several requests are associated with one
Study - or even Series (IHE group case).

If such solution sounds reasonable also for others (comments?), I
volunteer to write a DICOM CP to extend the Request Attributes Macro
(PS 3.3 - 2006 Page 78) with
>Requesting Service (0032,1033)
>Requesting Physician (0032,1032)

and additional:
>Requested Procedure Description (0032,1060)
>Requested Procedure Code Sequence (0032,1064)
>>Include Code Sequence Macro


We have already seen such attributes (except Requesting Service
(0032,1033)) included in the Composite Objects exported from modalities
in the base dataset (=not nested in the Request Attributes Sequence
(0040,0275)). Because non of them is currently listed by DICOM
Composite Object IODs, it's undefined, to which entity (Study or
Series) they belongs. Another reason, for an CP to clarify the existing
practice.

gunter zeilinger
Agfa HealthCare
Vienna/Europe