W3C

– DRAFT –
FHIR RDF

10 April 2025

Attendees

Present
David Booth, Detlef Grittner, Erich Bremer, Jim Balhoff
Regrets
-
Chair
David Booth
Scribe
dbooth

Meeting minutes

DICOM

erich: I've updated my code to convert values to meters. Need to test it.
… i'm only converting the polygon data.
… Maybe should use complex datatypes that Olaf proposed.
… We might have a complete conversion to RDF for all of the metadata, but not the data itself, like images.
… The polygons make sense to convert, to use geosparql.

https://olafhartig.de/files/HartigEtAl_SPARQLCDTs_PosterPaper2024.pdf

HAPI FHIR

jim: EricP and I will meet to discuss

DICOM

detlef: If we don't know what an array is, then wonder what to do with it.
… The proposed complex data type puts the data into a list. There's also a proposal to add sparql operators to work on them.
… Is there a way to detect these arrays of data?

detlef: Everytime the data value multiplicity is > 1, then it's an array.

erich: I'll take a look at it, and try it.
… As a command-line option
… When we discuss with the DICOM group, the options will be discussion points with them.

DICOM issue Using the entity-relationship model of the real world of DICOM #159

w3c/hcls-fhir-rdf#159

detlef: If there is a link, it should be to the whole object, not the part.

erich: Could we use this to factor out data that is common to all? detlef: Yes
… E.g., study

detlef: Everyone knows which attributes belong to the series.
… Want the triplestore to auto-merge the items in the series -- factoring out the redundant info.
… That makes querying much faster.

erich: I need to look at this. We have > 25M files. Some files have illegal xsd datetypes. When the data is generated (>5B triples), having the redundant data won't be efficient. What you're proposing is the way to go.

detlef: That's what we've done.

erich: I wasn't aware of the DICOM DIR files previously.
… But I don't yet apply the transforms that you're proposing.

detlef: The SOP instance UID is the UID of a very large object.
… We have a series resource, and say that it contains some other resource.

ACTION: Detlef to add an example to the github issue

erich: Things like age need to stay with the SOP instance.

detlef: Patient age belongs to a study, not to the patient.
… But you need to know which attributes belong to study, etc. They have normative XML files that define the DICOM schema

detlef: The OWL representation that we generate from the normative XML files are pretty much 1:1.
… Wonder if a SHACL representation might be more suitable.

erich: I'm defining them as their own shapes.

(Jim departs)

ADJOURNED

Summary of action items

  1. Detlef to add an example to the github issue
Minutes manually created (not a transcript), formatted by scribe.perl version 244 (Thu Feb 27 01:23:09 2025 UTC).

Diagnostics

No scribenick or scribe found. Guessed: dbooth

Maybe present: detlef, erich, jim

All speakers: detlef, erich, jim

Active on IRC: dbooth