Imaging informatics — reference

Reference · Dense lookup material — the verb tables, profile versions, HL7/FHIR bridge, and failure-mode catalogue. Teaching versions live in the chapter.

Actors (functions, not fixed wiring)

Actor	Function
Modality	scanner producing DICOM objects
PACS	store, query, distribution, viewer/workstation
VNA	standards-based (DICOM) archive role (longer-term/cross-vendor)
RIS	scheduling, ordering, worklists, reporting, status
EHR	hospital-wide clinical record
AI / quant service	consumer of images, producer of derived objects

Real deployments blur PACS/VNA, fold RIS into EHR, and place the AI service inside or outside the archive.

DIMSE verbs (classic networking)

AEs (AE Title + host/port); SCU = client, SCP = server; association negotiates Presentation Contexts (SOP Classes + Transfer Syntaxes).

Operation	Verb	What it does
C-STORE	send	push an object to an SCP
C-FIND	query	search by keys
C-MOVE	retrieve (via move)	source SCP sends to a destination AE (third party)
C-GET	retrieve (to self)	source SCP sends back to me (often disabled)
Q/R	C-FIND + C-MOVE/C-GET	find-then-pull loop
MWL	worklist	C-FIND against the worklist

C-MOVE is three-party: asker tells source to push to a separate destination AE. Final status is precise (PS3.4 Table C.4-2): 0000 Success = all C-STOREs succeeded; B000 Warning = one or more sub-operations failed; A801 Failure = Move Destination unknown (no C-STOREs attempted); other failures include A701/A702 (out of resources) and Cxxx (unable to process). A destination/connectivity/storage failure is therefore never 0000 — it surfaces as B000 or a Failure code. “Nothing arrived despite Success” = delivered to a different named destination, not the asker (expectation mismatch, not a protocol lie).

DICOMweb (HTTP re-skin, parallel transport)

Service	Maps to	What it does
QIDO-RS	C-FIND	query studies/series/instances via HTTP
WADO-RS	C-GET	retrieve objects/pixels/metadata via HTTP
STOW-RS	C-STORE	upload objects via HTTP
UPS-RS	workitem/workflow	REST interface to the DICOM Unified Procedure Step

Auth (HTTP/OAuth vs DIMSE/TLS/ACL), paging, and batching differ by transport. Viewer capability problems (e.g. cannot render SEG) are transport-independent.

Structured results

• DICOM SEG — segmentation referencing source series/SOPs + geometry (Ch. 4).
• DICOM SR — tree of coded findings/measurements referencing source images.
• Measurements / provenance — SR can encode measurements with source refs; capture provenance (model/version/inputs/time) or the result is unauditable.
• Screenshots/PDFs are display artefacts: not queryable/computable/linkable.

IHE profiles (recipes; all Trial Implementation; verified profiles.ihe.net)

Profile	Full name	Addresses
AIW-I	AI Workflow for Imaging (Rev 1.1, TI 2020)	inference workflow on UPS-RS — dispatch/track tasks
AIR	AI Results (Rev 1.3, TI 2025)	storage/retrieval/display of structured AI results
AIRA	AI Result Assessment for Imaging (PC→TI 2025)	assessment/feedback/monitoring/drift (post-market)

HL7 / FHIR bridge

DICOM = images/imaging objects; HL7 = orders/results/demographics. Order: RIS→modality (MWL), RIS↔EHR (HL7). Result: reporting→RIS→EHR (HL7, increasingly FHIR). FHIR matters because discrete measurements/AI findings need to land as structured resources (e.g. Observation), not PDFs.

FHIR resources for imaging workflow (verified: FHIR R5, hl7.org, retrieved 2026-08-29)

Resource	Verified definition (condensed)	Imaging-workflow role
ServiceRequest	“A record of a request for service such as diagnostic investigations, treatments, or operations to be performed”; request resource, intent = proposal/plan/directive/order	the order; carries the accession as an identifier
ImagingStudy	“Representation of the content produced in a DICOM imaging study”; identifier = DICOM StudyInstanceUID (urn:dicom:uid); basedOn → ServiceRequest (ACSN)	the DICOM study outside the imaging subsystem; endpoints → WADO-RS
DiagnosticReport	“The findings and interpretation of diagnostic tests performed on patients…”; event resource; study → ImagingStudy, result → Observation; basedOn → ServiceRequest	the report linking request, study, and atomic results
Observation	“Measurements and simple assertions made about a patient, device or other subject” (Normative since v4.0.0); derivedFrom → ImagingStudy/ImagingSelection	discrete measurements, e.g. an AI-derived volume

The mapping from DICOM objects and HL7 v2 messages is not one-to-one; real integrations follow IHE profiles and implementation guides.

Conformance, Storage Commitment and workflow services (verified DICOM 2026c; retrieved 2026-08-29)

• Conformance Statements: purpose and comparison claim — PS3.2 §6 (“a knowledgeable user should be able to determine whether and to what extent communications might be supported”); normative template — PS3.2 Annex N (per-AE SOP Classes with SCU/SCP roles, Transfer Syntaxes, options; tables N.5-10…N.5-12 document levels of storage support, attribute coercion, display/processing limitations).
• Storage Service Class conformance material: PS3.4 Annex B (B.4.1 levels of storage support; B.4.1.3 attribute coercion).
• Storage Commitment: PS3.4 Annex J — Storage Commitment Push Model SOP Class (N-ACTION request → N-EVENT-REPORT result with committed/failed lists; asynchronous); Pull Model retired (J.4).
• Workflow services: Modality Worklist (C-FIND) — PS3.4 Annex K (K.6.1); Modality Performed Procedure Step (N-CREATE/N-SET) — PS3.4 Annex F (F.7); Unified Worklist and Procedure Step (UPS) — the web-service successor used by IHE AIW-I.
• De-identification: PS3.15 Annex E — Basic Application Level Confidentiality Profile: action codes D/Z/X/K/C/U; options (Retain Longitudinal Full/Modified Dates, Retain UIDs, Retain Safe Private, Retain Device/Institution Identity, Retain Patient Characteristics, Clean Pixel Data, Clean Recognizable Visual Features, Clean Graphics, Clean Structured Content, Clean Description); Encrypted Attributes Data Set; Patient Identity Removed (0012,0062) + De-identification Method Code Sequence. Annex E states profiles “do not replace a de-identification process, but should be part of it”.
• Legal layer: GDPR (EU) 2016/679 Art. 4(1) personal data, Art. 4(5) pseudonymisation, Recitals 26/28 (identifiability/anonymous data); anonymisation is a contextual legal determination (EDPB guidance), not a DICOM output.

Failure-mode catalogue

Silent resampling · identity mismatch / wrong patient · lost provenance · worklist collision · AI result not retrievable · no audit trail · de-id leaks. Diagnose “deployed but ignored” via viewer capability, study linkage, timing, provenance — before blaming the model.

TRACE-CT connection

Single-machine/local today, so networking is future — but it practises informatics discipline: the QC-bundle schema encodes provenance (SHA-256 of inputs/outputs, pipeline version, geometry entries), review aggregation produces privacy-safe aggregate evidence, and the SEG objects it decodes are exactly the structured-derived-object handling described here. The EuSoMII AI-assisted workflow pipeline is the deployment shape this chapter explains.

What to retain (chapter summary)

1. Actors: modality → PACS/VNA → AI service → derived object → reporter → EHR; RIS owns order/worklist.
2. DIMSE verbs (C-STORE/C-FIND/C-MOVE/C-GET, Q/R, MWL) vs DICOMweb (QIDO/WADO/STOW, UPS) — same concepts, two transports. C-MOVE is three-party.
3. Structured results (SEG, SR, measurements + provenance) ≠ screenshots/PDFs.
4. A large share of imaging-AI failures are identity/provenance/retrieval failures; IHE profiles (AIW-I, AIR, AIRA) are the integration recipes.
5. Imaging is one subsystem in the hospital’s HL7/FHIR fabric; results must cross that bridge to affect care.