1. RSNA 2007 – Course Electronic Reports: HL7 CDA (Clinical Document Architecture) and DICOM SR (Structured Reporting)
Harry Solomon
GE Healthcare
DICOM WG 8 Structured Reporting
HL7 Structured Documents TC
DICOM WG 20 / HL7 Imaging Integration SIG
IHE Cross-Domain Reporting Task Force

2. Disclosure
Harry Solomon
Employee, GE Healthcare

3. Acknowledgements
Fred Behlen, co-author of a previous version of this presentation
Fred Behlen, Bob Dolin, Liora Alschuler, Calvin Beebe – co-chairs of HL7 Structured Documents Technical Committee, and authors of presentations on CDA used in this talk
Dave Clunie – former co-chair of DICOM Standards Committee, and author of the definitive book on DICOM Structured Reporting
Kevin O’Donnell – IHE Reporting Task Force

4. Objectives
Understand the key elements for effective radiology reporting, and issues with electronic reporting
Understand the HL7 CDA (Clinical Document Architecture) and its use cases
Understand DICOM SR (Structured Reporting) and its use cases
Understand reporting workflows, the use of DICOM SR and HL7 CDA in those workflows, and the importance of the IHE (Integrating the Healthcare Enterprise) effort

5. Key Elements of Radiology Reporting

6. Paper or Electronic Reports
Accurately convey the findings to the referring physician
Reflect the competence of the radiologist
Timely communication for patient care
Archived in the patient medical record
Legal record of imaging exam
Radiologist signature
Support ‘secondary’ uses
Charge capture and billing
Teaching and research
Clinical data registries, clinical trials
Process improvement
Produced making best use of radiologist’s time
Typical busy radiologist at
Northwestern Memorial Hospital

7. Benefits and challenges of Electronic Reports (1)
Accuracy
Drive for quality improvement with quantitative data, CAD and other measurements
Possible major benefit with attached key images and graphical analysis (picture = 1000 words)
Will systems support graphical reports?
Timely communication
Probable improvement
Archived in the patient medical record
Where is the electronic medical record? (distributed, multiple copies)

8. Benefits and challenges of Electronic Reports (2)
Legal record
What is a valid electronic signature?
Is an exact visual reproduction required, or only exact semantic content?
Secondary uses
Huge potential improvement, especially with structured and coded data
Use of radiologist’s time
Potential negative impact with transition from traditional dictation workflow
Radiologist pays the cost for improvements downstream

9. This is Process Re-engineering!
Transition to electronic reports is hard
New systems
New architectures
New policies and procedures
Organizationally disjunct costs/benefits
Minimize the risk and the effort
A standards-based approach
Incremental evolution from current workflow
Leverage 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:
Persistence
Stewardship
Potential for authentication
Wholeness
Human readability
A 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
Persistence
Documents exist over time and can be used in many contexts
Stewardship
Documents must be managed, shared by the steward
Potential for authentication
Intended use as medico-legal documentation
Wholeness
Document includes its relevant context
Human readability
Essential for human authentication

13. CDA Use Cases Diagnostic and therapeutic procedure reports
Encounter / discharge summaries
Patient history & physical
Referrals
Claims attachments
Consistent format for all clinical documents

14. Key Aspects of the CDA
CDA 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 Types
A CDA document consists of a header and a body
Header is consistent across all clinical documents - identifies and classifies the document, provides information on patient, provider, encounter, and authentication
Body 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 standard
Based on early draft v3 RIM
Level 1 narrative and multimedia
Release 2 (2005)
Incorporated into HL7 v3 Standard (Normative Edition)
Level 2 structured narrative and multimedia, plus Level 3 coded statements
Implementation Guides
HL7 Care Record Summary (CRS)
ASTM/HL7 Continuity of Care Document (CCD)
IHE Patient Care Coordination Templates

16. CDA Release 2 Information Model
Header
Body
Start
Here
Participants
Doc ID
&Type
Context
Sections/ Headings
Clinical Statements/
Coded Entries
Extl
Refs

17. CDA Structured Body Arrows are Act Relationships
Has component, Derived from, etc.
Entries are coded clinical statements
Observation, Procedure, Substance administration, etc.
Structured Body
Section
Text
Section
Text
Section
Text
Section
Text
Section
Text
Section
Text
Entry
Coded statement
Entry
Coded statement
Entry
Coded statement

18. Sample CDA

19. Narrative and Coded Info
CDA structured body requires human-readable “Narrative Block”, all that is needed to reproduce the legally attested clinical content
CDA allows optional machine-readable coded “Entries”, which drive automated processes
Narrative may be flagged as derived from Entries
Textual rendering of coded entries’ content, and contains no clinical content not derived from the entries
General method for coding clinical statements is a hard, unsolved problem
CDA allows incremental improvement to amount of coded data without breaking the model

20. Narrative and Coded Entry Example

21. CDA Non-XML Body Alternative to XML Structured Body
Standard CDA header “wraps” existing document
Any MIME type
Especially PDF (IHE Scanned Document Profile)

22. CDA Implementation Guides
Published by HL7
Care Record Summary – encounter notes, discharge summary
Continuity of Care Document – transfer of care (harmonized with ASTM Continuity of Care Record)
Published by IHE Patient Care Coordination
Emergency Department Referral
Pre-procedure History and Physical
Scanned Documents
Personal Health Record Extract
Basic Patient Privacy Consents
Antepartum Summary
Emergency 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 images
Computer-aided detection results
Notes about images (QC, flag for specific use, quick reads)
Procedure logs for imaging-based therapeutic procedures
Image exchange manifests

26. Use Case Common Features
Structured
Lists and hierarchies
Numeric measurements, coded values
Automatically extractable for database, data mining
Relationships between items
Hierarchical, or arbitrary reference
Power of rich semantic expression
References to images, waveforms, other objects
Collected in DICOM environment
Explicit contextual information
Unambiguous documentation of meaning

27. DICOM SR and the Five Clinical Document Characteristics
The five characteristics:
Persistence: SR objects are persistent
Stewardship: SR objects are managed and can identify their steward
Potential for authentication: SR has digital signature capability
Wholeness: SR objects include their relevant context
Human readability: DICOM requires SR objects to be rendered “completely and unambiguously”, but this needs a conformant application
SR 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 SR
SR 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 content
Allows use of vocabulary/codes from non-DICOM sources
Templates 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 meaning
Text, Numeric, Code, Image, Spatial coordinates, etc.
Root Content Item
Document Title
Content Item
Content Item
Content Item
Content Item
Content Item
Content Item
Content Item
Content Item
Content Item

30. DICOM SR Example

31. DICOM SR Object Classes
Basic Text - Narrative text with image references
Enhanced and Comprehensive - Text, coded content, numeric measurements, spatial and temporal ROI references
CAD - Automated analysis results (mammo, chest, colon)
Key Object Selection (KO) - Flags one or more images
Purpose (for referring physician, for surgery …) and textual note
Used 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 Reporting
Standard DICOM header “wraps” existing document
Allows use of DICOM infrastructure – object exchange, archive (PACS), query/retrieve
Only specific document types allowed
PDF
CDA

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 locales
PDF allows exact visual reproduction, and display software is readily available
Role for PDF as a presentation-ready equivalent rendering of a coded document
Both 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 document
Also supports legacy documents scanned into PDF

34. Radiology Reporting Workflows

35. Reporting Starts Before the Radiologist Sees the Study
Reason for exam (from order)
Technical aspects of procedure
Protocol
Exam notes from tech
Post-processing results
Measurement and analysis applications (e.g., vascular, obstetric, cardiac) by tech
Computer Aided Detection results
These need to get to the radiologist and integrated into the report
Produced on modality or imaging workstation

36. Reporting Integration (1)
Review study evidence
Order and relevant clinical information
Images and relevant priors
Tech notes and post-processing results
Radiologist interpretation – on imaging workstation
Annotation (virtual grease pencil)
Key image selection
Measurement and analysis applications by radiologist
Radiologist findings reporting – on a different system?
Structured data entry (forms-based)
Dictation + transcription
Where’s Waldo going to prepare his report?

37. Reporting Integration (2)
Report assembly
Findings and selected evidence/interpretation results
Radiologist signature
Auditable action, or digital encryption-based
Report communication
To referring physician
To “secondary” users (billing!)
Report archive
And subsequent access

38. The DICOM Solution?
DICOM was supposed to take care of all this, and has (almost) all the requisite features and network services
DICOM SR has found vital uses in key subspecialty areas that produce structured data in the examination or post-processing
Leveraging the DICOM infrastructure is easy and desirable
Results managed with other study evidence
But the end recipients of radiology reports, referring physicians, commonly use systems without DICOM capabilities (imaging or SR)

39. “Evidence” and “Reports”
Evidence Documents
Includes measurements, procedure logs, CAD results, etc., created in the imaging context, and together with images are interpreted by a radiologist to produce a report
The radiologist may quote or copy parts of Evidence Documents into the report, but doing so is part of the interpretation process at his discretion
Appropriate to be stored in PACS as DICOM SR objects, with same (legal/distribution) status as images
Reports
Become part of the patient’s medical record, with potentially wide distribution
Ideal 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 together
DICOM SR and HL7 CDA are congruent in key areas
Document persistence
Document identification, versioning and type code
Document’s relation to the patient and to the authoring physicians
SR strength in robust image-related semantic content; CDA strength in human readable narrative report
DICOM 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 versa
Include CDA documents on DICOM removable disks
As native CDA files, or encapsulated in a DICOM file
Indexed in DICOMDIR for integration with DICOM applications
PDF rendering of SR can be wrapped in a CDA document
Transcoding between SR and CDA feasible for limited subset of reports
CDA 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 integration
Practical evolution from current architectures
Venue for testing implementations and interoperability
Reporting is a high priority task for Radiology Domain
Your participation is welcome!

43. Reporting Profiles Documented workflow profiles
IHE Evidence Documents Profile
IHE Key Image Notes Profile
DICOM Part 17 Dictation-Based Reporting with Image References [Supplement 101]
Ongoing work in IHE Reporting Task Force and Radiology Technical Committee
Revise IHE Simple Image and Numeric Report Profile, consolidate with Post-processing and Reporting Workflow Profiles
Align with Retrieve Information for Display and Cross-Enterprise Document Sharing Profiles

44. Image Viewing Application Reporting Application
Diagnostic reporting
Image Viewing Application
Reporting Application
User control
Diagnostic report
Orders,
Prior
Reports
Diagnostic
Images
Viewing settings
Report
Image Sources
PACS Archive
Information System

45. Reporting with annotation (use case - desired)
Image Viewing Application
Reporting Application
User control
Diagnostic report
Image references & annotation
Report with image references & annotation
Orders,
Prior
Reports
Diagnostic
Images
Viewing settings
Image Sources
PACS Archive
Information System

46. Reporting with annotation (what’s available)
Image Viewing Application
Reporting Application
User control
Diagnostic report
Image references & annotation
Orders,
Prior
Reports
Viewing settings, image references & annotation
Diagnostic
Images
Report
Image Sources
PACS Archive
Information System

47. Integrated solution Image Viewing & Reporting Application User control
Diagnostic report
Image references & annotation
Orders,
Diagnostic images & Prior reports
Viewing settings,
Reports, image
references & annotation
Image Sources
Integrated PACS & Information System

48. Loosely integrated reporting
Image Viewing Application
Reporting Application
User control
Diagnostic report
Image references & annotation
Orders,
Prior
Reports
Viewing settings, image references & annotation
Diagnostic
Images
Report
Image references & annotation
Image retrieval
Image Sources
PACS Archive
Information System
Report w/ image ref & annot

49. Image Viewing Application Reporting Application Image selection
Dictated report
Annotation
Verification
Transcribed narrative
DICOM
GSPS object (annotations)
DICOM
KO object “For Report”
Reporting System Validation Functions
DICOM Query/Retrieve for all KO objects matching Accession Number
Image Archive
(DICOM SCP)
Reporting Integration Functions
DICOM
Encapsulated CDA object
CDA Report
WADO
Server
WADO 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 workflows
Need consensus approaches to specific use cases (IHE)
Quantitative measurement intensive reporting with DICOM SR inputs
Mammo with CAD input, Obstetric with sonographer measurements, Cardiac with functional assessments
DICOM 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 workflow
Possible push model of key measurements to RIS?

51. Conclusions
CDA now viewed as a primary format for diagnostic imaging reports
Definition of CDA DI report to be done in 2008 by a balloted HL7 Implementation Guide
Method is extensible to reports with more structure
DICOM SR will see continued and expanding use for Evidence Documents created in the imaging setting
IHE Evidence Documents Integration Profile
Evolutionary workflows utilizing both standards in coordination are being profiled by IHE
Does not require tight integration of imaging and reporting workstations