3 AcknowledgementsFred Behlen, co-author of a previous version of this presentationFred Behlen, Bob Dolin, Liora Alschuler, Calvin Beebe – co-chairs of HL7 Structured Documents Technical Committee, and authors of presentations on CDA used in this talkDave Clunie – former co-chair of DICOM Standards Committee, and author of the definitive book on DICOM Structured ReportingKevin O’Donnell – IHE Reporting Task Force
4 ObjectivesUnderstand the key elements for effective radiology reporting, and issues with electronic reportingUnderstand the HL7 CDA (Clinical Document Architecture) and its use casesUnderstand DICOM SR (Structured Reporting) and its use casesUnderstand reporting workflows, the use of DICOM SR and HL7 CDA in those workflows, and the importance of the IHE (Integrating the Healthcare Enterprise) effort
6 Paper or Electronic Reports Accurately convey the findings to the referring physicianReflect the competence of the radiologistTimely communication for patient careArchived in the patient medical recordLegal record of imaging examRadiologist signatureSupport ‘secondary’ usesCharge capture and billingTeaching and researchClinical data registries, clinical trialsProcess improvementProduced making best use of radiologist’s timeTypical busy radiologist atNorthwestern Memorial Hospital
7 Benefits and challenges of Electronic Reports (1) AccuracyDrive for quality improvement with quantitative data, CAD and other measurementsPossible major benefit with attached key images and graphical analysis (picture = 1000 words)Will systems support graphical reports?Timely communicationProbable improvementArchived in the patient medical recordWhere is the electronic medical record? (distributed, multiple copies)
8 Benefits and challenges of Electronic Reports (2) Legal recordWhat is a valid electronic signature?Is an exact visual reproduction required, or only exact semantic content?Secondary usesHuge potential improvement, especially with structured and coded dataUse of radiologist’s timePotential negative impact with transition from traditional dictation workflowRadiologist pays the cost for improvements downstream
9 This is Process Re-engineering! Transition to electronic reports is hardNew systemsNew architecturesNew policies and proceduresOrganizationally disjunct costs/benefitsMinimize the risk and the effortA standards-based approachIncremental evolution from current workflowLeverage the work of IHE (Integrating the Healthcare Enterprise)
10 HL7 Clinical Document Architecture Overview HL7 is a Standards Development Organization whose domain is clinical and administrative data
11 HL7 Clinical Document Architecture The scope of the CDA is the standardization of clinical documents for exchange.A clinical document is a record of observations and other services with the following characteristics:PersistenceStewardshipPotential for authenticationWholenessHuman readabilityA CDA document is a defined and complete information object that can exist outside of a message, and can include text, images, sounds, and other multimedia content.
12 Clinical Document Characteristics PersistenceDocuments exist over time and can be used in many contextsStewardshipDocuments must be managed, shared by the stewardPotential for authenticationIntended use as medico-legal documentationWholenessDocument includes its relevant contextHuman readabilityEssential for human authentication
13 CDA Use Cases Diagnostic and therapeutic procedure reports Encounter / discharge summariesPatient history & physicalReferralsClaims attachmentsConsistent format for all clinical documents
14 Key Aspects of the CDACDA documents are encoded in Extensible Markup Language (XML)CDA documents derive their meaning from the HL7 v3 Reference Information Model (RIM ) and use HL7 v3 Data TypesA CDA document consists of a header and a bodyHeader is consistent across all clinical documents - identifies and classifies the document, provides information on patient, provider, encounter, and authenticationBody contains narrative text / multimedia content (level 1), optionally augmented by coded equivalents (levels 2 & 3)
15 CDA Standard Release 1 (2000) Release 2 (2005) Implementation Guides Standalone standardBased on early draft v3 RIMLevel 1 narrative and multimediaRelease 2 (2005)Incorporated into HL7 v3 Standard (Normative Edition)Level 2 structured narrative and multimedia, plus Level 3 coded statementsImplementation GuidesHL7 Care Record Summary (CRS)ASTM/HL7 Continuity of Care Document (CCD)IHE Patient Care Coordination Templates
16 CDA Release 2 Information Model HeaderBodyStartHereParticipantsDoc ID&TypeContextSections/ HeadingsClinical Statements/Coded EntriesExtlRefs
17 CDA Structured Body Arrows are Act Relationships Has component, Derived from, etc.Entries are coded clinical statementsObservation, Procedure, Substance administration, etc.Structured BodySectionTextSectionTextSectionTextSectionTextSectionTextSectionTextEntryCoded statementEntryCoded statementEntryCoded statement
19 Narrative and Coded Info CDA structured body requires human-readable “Narrative Block”, all that is needed to reproduce the legally attested clinical contentCDA allows optional machine-readable coded “Entries”, which drive automated processesNarrative may be flagged as derived from EntriesTextual rendering of coded entries’ content, and contains no clinical content not derived from the entriesGeneral method for coding clinical statements is a hard, unsolved problemCDA allows incremental improvement to amount of coded data without breaking the model
21 CDA Non-XML Body Alternative to XML Structured Body Standard CDA header “wraps” existing documentAny MIME typeEspecially PDF (IHE Scanned Document Profile)
22 CDA Implementation Guides Published by HL7Care Record Summary – encounter notes, discharge summaryContinuity of Care Document – transfer of care (harmonized with ASTM Continuity of Care Record)Published by IHE Patient Care CoordinationEmergency Department ReferralPre-procedure History and PhysicalScanned DocumentsPersonal Health Record ExtractBasic Patient Privacy ConsentsAntepartum SummaryEmergency Department Encounter Summary
23 DICOM Structured Reporting Overview DICOM is a Standards Development Organization whose domain is biomedical imaging
24 DICOM Structured Reporting The scope of DICOM SR is the standardization of documents in the imaging environment.SR documents record observations made for an imaging-based diagnostic or interventional procedure, particularly those that describe or reference images, waveforms, or specific regions of interest.
25 SR Use Cases Radiology reports with robust image / ROI references Measurements/analyses made on imagesComputer-aided detection resultsNotes about images (QC, flag for specific use, quick reads)Procedure logs for imaging-based therapeutic proceduresImage exchange manifests
26 Use Case Common Features StructuredLists and hierarchiesNumeric measurements, coded valuesAutomatically extractable for database, data miningRelationships between itemsHierarchical, or arbitrary referencePower of rich semantic expressionReferences to images, waveforms, other objectsCollected in DICOM environmentExplicit contextual informationUnambiguous documentation of meaning
27 DICOM SR and the Five Clinical Document Characteristics The five characteristics:Persistence: SR objects are persistentStewardship: SR objects are managed and can identify their stewardPotential for authentication: SR has digital signature capabilityWholeness: SR objects include their relevant contextHuman readability: DICOM requires SR objects to be rendered “completely and unambiguously”, but this needs a conformant applicationSR emphasizes coded semantic content (especially in relation to images), while CDA emphasizes human readable text through simple XML style sheets
28 Key Aspects of DICOM SRSR documents are encoded using DICOM standard data elements and leverage DICOM network services (storage, query/retrieve)SR uses DICOM Patient/Study/Series information model (header), plus hierarchical tree of “Content Items”Extensive mandatory use of coded contentAllows use of vocabulary/codes from non-DICOM sourcesTemplates define content constraints for specific types of documents / reports
29 SR Content Item Tree Arrows are parent-child relationships Contains, Has properties, Inferred from, etc.Content Items are units of meaningText, Numeric, Code, Image, Spatial coordinates, etc.Root Content ItemDocument TitleContent ItemContent ItemContent ItemContent ItemContent ItemContent ItemContent ItemContent ItemContent Item
31 DICOM SR Object Classes Basic Text - Narrative text with image referencesEnhanced and Comprehensive - Text, coded content, numeric measurements, spatial and temporal ROI referencesCAD - Automated analysis results (mammo, chest, colon)Key Object Selection (KO) - Flags one or more imagesPurpose (for referring physician, for surgery …) and textual noteUsed for key image notes and image manifests (in IHE profiles)Procedure Log - For extended duration procedures (e.g., cath)Radiation Dose Report - Projection X-ray; CT
32 DICOM Encapsulated Document Complementary to DICOM Structured ReportingStandard DICOM header “wraps” existing documentAllows use of DICOM infrastructure – object exchange, archive (PACS), query/retrieveOnly specific document types allowedPDFCDA
33 PDF (Adobe® Portable Document Format) Neither CDA nor SR guarantee exact visual reproduction of a displayed document, which may be a legal requirement in some localesPDF allows exact visual reproduction, and display software is readily availableRole for PDF as a presentation-ready equivalent rendering of a coded documentBoth CDA and DICOM support wrapping PDF with their standard header, so a presentation-ready PDF can be managed in the same environment with cross-links to the original coded documentAlso supports legacy documents scanned into PDF
35 Reporting Starts Before the Radiologist Sees the Study Reason for exam (from order)Technical aspects of procedureProtocolExam notes from techPost-processing resultsMeasurement and analysis applications (e.g., vascular, obstetric, cardiac) by techComputer Aided Detection resultsThese need to get to the radiologist and integrated into the reportProduced on modality or imaging workstation
36 Reporting Integration (1) Review study evidenceOrder and relevant clinical informationImages and relevant priorsTech notes and post-processing resultsRadiologist interpretation – on imaging workstationAnnotation (virtual grease pencil)Key image selectionMeasurement and analysis applications by radiologistRadiologist findings reporting – on a different system?Structured data entry (forms-based)Dictation + transcriptionWhere’s Waldo going to prepare his report?
37 Reporting Integration (2) Report assemblyFindings and selected evidence/interpretation resultsRadiologist signatureAuditable action, or digital encryption-basedReport communicationTo referring physicianTo “secondary” users (billing!)Report archiveAnd subsequent access
38 The DICOM Solution?DICOM was supposed to take care of all this, and has (almost) all the requisite features and network servicesDICOM SR has found vital uses in key subspecialty areas that produce structured data in the examination or post-processingLeveraging the DICOM infrastructure is easy and desirableResults managed with other study evidenceBut the end recipients of radiology reports, referring physicians, commonly use systems without DICOM capabilities (imaging or SR)
39 “Evidence” and “Reports” Evidence DocumentsIncludes measurements, procedure logs, CAD results, etc., created in the imaging context, and together with images are interpreted by a radiologist to produce a reportThe radiologist may quote or copy parts of Evidence Documents into the report, but doing so is part of the interpretation process at his discretionAppropriate to be stored in PACS as DICOM SR objects, with same (legal/distribution) status as imagesReportsBecome part of the patient’s medical record, with potentially wide distributionIdeal match to HL7 CDA, but sometimes SR is appropriate
40 DICOM-HL7 Synergy (1) SR and CDA developed simultaneously DICOM and HL7 working groups recognized the need to work togetherDICOM SR and HL7 CDA are congruent in key areasDocument persistenceDocument identification, versioning and type codeDocument’s relation to the patient and to the authoring physiciansSR strength in robust image-related semantic content; CDA strength in human readable narrative reportDICOM WG10 (Strategic Advisory) suggested composing radiology reports directly in CDA format when appropriate
41 DICOM-HL7 Synergy (2)References to CDA documents from within DICOM objects, and vice versaInclude CDA documents on DICOM removable disksAs native CDA files, or encapsulated in a DICOM fileIndexed in DICOMDIR for integration with DICOM applicationsPDF rendering of SR can be wrapped in a CDA documentTranscoding between SR and CDA feasible for limited subset of reportsCDA Implementation Guide for Diagnostic Reporting in development
42 The Role of IHE Industry-wide effort to “make it work” Real world use cases drive standards-based approach to integrationPractical evolution from current architecturesVenue for testing implementations and interoperabilityReporting is a high priority task for Radiology DomainYour participation is welcome!
43 Reporting Profiles Documented workflow profiles IHE Evidence Documents ProfileIHE Key Image Notes ProfileDICOM Part 17 Dictation-Based Reporting with Image References [Supplement 101]Ongoing work in IHE Reporting Task Force and Radiology Technical CommitteeRevise IHE Simple Image and Numeric Report Profile, consolidate with Post-processing and Reporting Workflow ProfilesAlign with Retrieve Information for Display and Cross-Enterprise Document Sharing Profiles
49 Image Viewing Application Reporting Application Image selection Dictated reportAnnotationVerificationTranscribed narrativeDICOMGSPS object (annotations)DICOMKO object “For Report”Reporting System Validation FunctionsDICOM Query/Retrieve for all KO objects matching Accession NumberImage Archive(DICOM SCP)Reporting Integration FunctionsDICOMEncapsulated CDA objectCDA ReportWADOServerWADO URI references to Images with GSPSs (JPEG rendering)
50 Other Use Cases to be Profiled All the basic elements are standardized and ready to be fit into integrated reporting workflowsNeed consensus approaches to specific use cases (IHE)Quantitative measurement intensive reporting with DICOM SR inputsMammo with CAD input, Obstetric with sonographer measurements, Cardiac with functional assessmentsDICOM SR as primary report with PDF wrapped in CDA as distributed version?Selected key measurements imported into report (loosely coupled architecture)Similar to Key Image / Annotation workflowPossible push model of key measurements to RIS?
51 ConclusionsCDA now viewed as a primary format for diagnostic imaging reportsDefinition of CDA DI report to be done in 2008 by a balloted HL7 Implementation GuideMethod is extensible to reports with more structureDICOM SR will see continued and expanding use for Evidence Documents created in the imaging settingIHE Evidence Documents Integration ProfileEvolutionary workflows utilizing both standards in coordination are being profiled by IHEDoes not require tight integration of imaging and reporting workstations