RSNA 2006

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RSNA 2006 Course 070 Electronic ReportsHL7
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

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Disclosure

• Harry Solomon
• Employee, GE Healthcare

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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 ODonnell IHE Reporting Task Force

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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

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Key Elements ofRadiology Reporting
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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 radiologists time

Typical busy radiologist at Northwestern
Memorial Hospital
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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)

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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 radiologists time
• Potential negative impact with transition from
  traditional dictation workflow
• Radiologist pays the cost for improvements
  downstream

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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)

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HL7 Clinical Document ArchitectureOverview
HL7 is a Standards Development Organization whose
domain is clinical and administrative data
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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.

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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

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CDA History

• 1996 initial discussions
• 1997 HL7 SGML SIG
• Use of Standard Generalized Markup Language for
  adding metadata to documents
• Later evolved to Extensible Markup Language (XML)
  subset of SGML
• Kona Editorial Group
• 1998 Patient Record Architecture draft
• 2000 Clinical Document Architecture Release 1
  adopted
• Limited to level 1
• 2000 SIG becomes HL7 Structured Documents
  Technical Committee
• 2005 Clinical Document Architecture Release 2
  adopted
• Expanded to levels 2 3
• 2006 CDA Care Record Summary Implementation
  Guide

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CDA Use Cases

• Diagnostic and therapeutic procedure reports
• Encounter / discharge summaries
• Patient history physical
• Referrals
• Claims attachments
• Consistent format for all clinical documents

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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)

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CDA Standard

• Release 1 (2000)
• 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 Guide for Care Record Summaries,
  US Realm (2006)

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

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Narrative and Coded Entry Example
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CDA Non-XML Body

• Alternative to XML Structured Body
• Standard CDA header wraps existing document
• Any MIME type
• Especially PDF (IHE Scanned Document Profile)

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CDA Implementation Guides

• Published by HL7
• Care Record Summary encounter notes, discharge
  summary
• Published by IHE Patient Care Coordination
• Emergency Department Referral
• Pre-procedure History and Physical
• Scanned Documents
• Personal Health Records
• Basic Patient Privacy Consents

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DICOM Structured ReportingOverview
DICOM is a Standards Development Organization
whose domain is biomedical imaging
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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.

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SR History

• 1994 initial discussions
• 1995 Working Group 8 (Structured Reporting)
• 1998 Supplement 23 Structured Reporting draft
• 1999-2000 Supplement 23 adopted
• 2001 Supplement 53 DICOM Content Mapping
  Resource adopted
• 2001-2006 12 Supplements defining specific SR
  document templates

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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

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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

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DICOM SR and the FiveClinical 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

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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

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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
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DICOM SR Example
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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 (in
  development)

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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 (2006)
• CDA (in ballot completion January 2007)

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PDF (AdobePortable 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

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Radiology ReportingWorkflows
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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

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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

Wheres Waldo going to prepare his report?
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Reporting Integration (2)

• Report assembly
• Findings and selected interpretation results
• Radiologist signature
• Report communication
• To referring physician
• To secondary users (billing!)
• Report archive
• And subsequent access

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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)

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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 patients medical record, with
  potentially wide distribution
• Ideal match to HL7 CDA, but sometimes SR is
  appropriate

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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
• Documents 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

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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

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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 highest priority task for Radiology
  Domain in 2007
• Your participation is welcome!

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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

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Diagnostic reporting
Image Viewing Application
Reporting Application
Usercontrol
Diagnosticreport
Orders, Prior Reports
Diagnostic Images
Viewingsettings
Report
PACSArchive
Information System
ImageSources
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Reporting with annotation(use case)
Image Viewing Application
Reporting Application
Usercontrol
Diagnosticreport
Imagereferences annotation
Reportwith imagereferences annotation
Orders, Prior Reports
Diagnostic Images
Viewingsettings
PACSArchive
Information System
ImageSources
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Reporting with annotation(whats available)
Image Viewing Application
Reporting Application
Usercontrol
Diagnosticreport
Imagereferences annotation
Orders, Prior Reports
Viewing settings,image references annotation
Diagnostic Images
Report
PACSArchive
Information System
ImageSources
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Integrated solution
Image Viewing Reporting Application
Usercontrol
Diagnosticreport
Imagereferences annotation
Orders, Diagnostic images Prior reports
Viewing settings, Reports, image references
annotation
Integrated PACS Information System
ImageSources
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Loosely integrated reporting
Image Viewing Application
Reporting Application
Usercontrol
Diagnosticreport
Imagereferences annotation
Orders, Prior Reports
Viewing settings,image references annotation
Diagnostic Images
Report
PACSArchive
Information System
ImageSources
Report w/ image ref annot
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Image Viewing Application
Reporting Application
Imageselection
Dictatedreport
Annotation
Verification
Transcribednarrative
DICOM GSPS object (annotations)
DICOM KO objectFor Report
Reporting SystemValidation Functions
DICOM Query/Retrieve for all KO objects matching
Accession Number
Reporting Integration Functions
Image Archive (DICOM SCP)
DICOM Encapsulated CDA object
CDAReport
WADO Server
WADO URI references toImages with GSPSs (JPEG
rendering)
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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?

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Conclusions

• CDA now viewed as a primary format for diagnostic
  imaging reports
• Definition of CDA DI report to be done in 2007 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