A universal viewer should launch with context, not with a blank search box
If a viewer launches from the EHR without patient or task context, the clinician has to re-find the same case manually. SMART launch exists to reduce that friction and make the viewer feel like part of the chart workflow rather than a separate island.
Representative SMART launch context
A simplified launch context payload showing the issuing FHIR server, launch handle, and patient or encounter context available to the app.
Click on an annotation to highlight it in the JSON
SMART App Launch scopes and launch context
Official HL7 SMART App Launch guidance for scopes and context parameters used during EHR launch.
Read the SMART launch-context guidanceSMART App Launch flow
Official HL7 SMART guidance for the launch sequence itself, complementing the narrower context-parameter reference.
Read the SMART app-launch flowContext synchronization prevents the viewer and chart from drifting apart
Launch gets the viewer into the right neighborhood. Ongoing context synchronization keeps it there. That is the role of FHIRcast: patient-open, imagingstudy-open, and report-related events let multiple applications move together instead of silently diverging.
EHR-to-viewer context flow
Loading diagram...
FHIRcast by itself defines events and subscription behavior. In imaging programs, IHE Interactive Reporting Applications (IRA) is useful because it turns those abstract hub interactions into concrete radiology actors such as an Image Display, Report Creator, Worklist Client, and Watcher.
FHIRcast patient-open
Official FHIRcast event describing shared patient-context synchronization across applications.
Read the patient-open event definitionFHIRcast imagingstudy-open
Official FHIRcast event for aligning applications on the same imaging study context.
Read the imagingstudy-open event definitionIHE Interactive Reporting Applications (IRA)
Official IHE Radiology profile that packages FHIRcast-style synchronization into concrete reporting-session actors and transactions.
Read the IRA profile overviewFHIR DiagnosticReport
Official HL7 resource for tying report context back to the study being viewed.
Read the DiagnosticReport resourceContext drift is a patient-safety problem, not just an integration nuisance
The viewer, report surface, and EHR can each be technically available and still be clinically unsafe if they drift onto different patients or studies. The risk is not abstract: a user can trust a viewer precisely because it launched from the chart, which makes wrong-context behavior more dangerous, not less.
- A stale viewer session can stay on an earlier patient while the chart moves on
- A study-open event may succeed in one subscriber but not another, leaving report and image context mismatched
- A report deep link without explicit study identity can open the “closest” case instead of the intended one
- Fallback manual search paths can silently bypass the context guarantees the launch flow was supposed to provide
Operational test
A viewer-EHR integration is not production-ready until the team has tested patient-switch, encounter-switch, and same-day multi-study scenarios end to end. Simple launch demos are not enough.
FHIRcast synchronization considerations
Official FHIRcast implementer guidance on out-of-sync states, end-user signaling, and why embedded clinical apps need explicit drift handling.
Read the synchronization guidanceFHIR ImagingStudy
Official HL7 resource used to carry explicit study identity so launch and report links can target the intended imaging context.
Read the ImagingStudy resourceKnowledge Check
Test your understanding with this quiz. You need to answer all questions correctly to mark this section as complete.