C-Find usage

[Alexander Rautenberg]

Hello,

in part PS 3.4, section C.4.1.2.1 of the standard, it says that in the
C-Find request you have to provide a single value for the unique key
attributes of all levels above the Q/R level. E.g., if the Q/R level
is "series", I have to specify a study UID (when using the study root
information model). It has to be a single value, so using "" or "*" is
not possible.
So, it seems that if I want to find all available series, at first I
have to issue a C-Find at study level to get all study UIDs. Then I
can run through the set of study UIDs and perform a C-Find at series
level for each one, finally querying the series information. But this
seems just too complex, doesn't it? Just wondering...

BTW, I'm using a DCM4CHEE PACS server for testing and that one does
not seem to care at all about whether there's a study UID specified in
a series query or not...

thanks,
Alex

[David Clunie]

You have described the correct procedure for a hierarchical
query. Whether you think it is excessively complex or not,
that is what you need to do.

Just because some SCPs do not require that relational queries
be negotiated to support them when an SCU attempts to perform
them, does not make that correct or portable.

Just because it works with dcm4che as an SCP, does not mean
it will work with other SCPs.

David

[gunterze]

Right, dcm4chee archive's Q/R SCP accepts query/retrieve requests
without (U)IDs for entities above the query/retrieve level, even if
relational queries/retrievals was not negotiated by the Q/R SCU - just
to reduce the number of service calls I have to deal with ;)
--
gunter