Hierarchies in sections Findings and Impression

[chgessner]

section:findings and section:impression both have entry slices for finding and keyImage.

section:impression has an entry slice for impression in addition.

I do not understand the way to express relations and possibly hierarchies between those (three) entry types. And should findings that relate to impressions be repeated in both sections then?

Maybe impressions could reference the findings (finding referernces, too be correct) as referenced in the findings section, instead of repeating them?

In my understanding, keyimages often serve as evidence to findings. How can this be expressed within the given (non-) hierarchy?

Can Observation.basedOn or Observation.partOf be used for that purpose?

[chgessner]

I found a large number of good examples or test cases in "IHE Radiology Technical Framework Supplement Imaging Diagnostic Report (IDR) Revision 1.0" https://www.ihe.net/uploadedFiles/Documents/Radiology/IHE_RAD_Suppl_IDR_Rev1-0_PC_2024-05-09.pdf

Partly reproduced in the corresponding FHIR IG work https://build.fhir.org/ig/IHE/RAD.IDR/index.html

[chgessner]

To the topic of hierarchies:

The FHIR Condition resource would allow for referencing back to Observations, DiagnosticReport etc. through evidence (or stage.assessment). But we have removed those elements in https://build.fhir.org/ig/hl7-eu/imaging/StructureDefinition-im-impression.html. How would we express such hierarchies then, e. g. between Conditions and Observation-as-evidence? Or to indicate what was used as the basis for staging/grading?

[bvdh]

stage.assessment is not removed, it is not labeled as must support. The use is still allowed although no requirement for them has been identified from the mapping process.

I think the best way to explore this issue is to map a report that has staging related conclusions and see what is required and whether we need to require more fields to be supported.

[kruzikh]

One more comment: why don't we use clinicalImpression resource which gives more expresibility then current entries in the improssion section?

[oijauregui]

For what I understand about the scope of the clinicalImpression resource, it aims more at consecutive assessments about a patient's health issue, allowing to capture evolution over time and care plan adaptation to those changes, rather than a one-off analysis, which is the case with reports.
I'm also hesitant to include a resource with maturity level 1 in the IG.

[oijauregui]

To the topic of hierarchies:

The FHIR Condition resource would allow for referencing back to Observations, DiagnosticReport etc. through evidence (or stage.assessment). But we have removed those elements in https://build.fhir.org/ig/hl7-eu/imaging/StructureDefinition-im-impression.html. How would we express such hierarchies then, e. g. between Conditions and Observation-as-evidence? Or to indicate what was used as the basis for staging/grading?

Condition.evidence would be the right place to encode the relation between Condition and Observation.
From the element description "The evidence may be a simple list of coded symptoms/manifestations, or references to observations or formal assessments, or both. For example, if the Condition.code is pneumonia, then there could be an evidence list where Condition.evidence.concept = fever (CodeableConcept), Condition.evidence.concept = cough (CodeableConcept), and Condition.evidence.reference = bronchitis (reference to Condition)."

And since it's a codeableReference, and it's not restricted in our ClinicalImpresion profile, it should work as is to achieve this relation binding.