Standards Selection Guide

    Standards Selection Guide

    Represents a collection of the recommended Standards, Resources, Implementation Guides created to satisfy a specific set of Clinical Requirement at a moment in time, following the discovery process presented in the guidance section of this site.

    Maturity Level
    • Under Development
    • Pilot
    • Draft For Use
    • Normative
    • Superseded (by...)
    • Retired
    Market Guidance

    PAN-CANADIAN RECOMMENDED

    Guide Status:

    • Draft
    • Published
    Effective Date

    June, 2015

    Key Contributors

    The following individuals/organizations contributed to the initial creation of the Canadian XDS Affinity Domain Implementation Guide, the basis of the content summarized in this resource:

    NameTitleOrganization
    Ben MacerolaSolution ArchitectCanada Health Infoway
    Kinson HoArchitectAgfa Healthcare
    Cezary Klimczak CEOLeafsprout Technologies
    Diane Larwood General ManagerMohawk Shared Services
    Chris Lindop Program Manager - InteroperabilityGE Healthcare
    Peter Popowycz ArchitectGTA-w
    Teri Sippel SchimdtBusiness DevelopmentKaros Health
    Table of Contents

    MaturityNormative
    StatusPublished
    StandardsIHE®, DICOM®, HL7® v2, SNOMED CT®
    DomainDiagnostic Imaging
    JurisdictionNational

     

     

     

     

    Purpose

    This guide provides an overview of the available standards and a recommended approach to support the Foreign Exam Management requirements as identified below. The intent is to simplify standards selection decisions in future projects and, in turn, to promote standardization of solutions across projects by providing useful information to support decision making in a readily consumable format.

    Content in this guide was summarized from the Canadian XDS Affinity Domain Implementation Guide to provide an accessible overview of the standards selected to support the listed Use Cases.

    Business Context

    The Foreign Exam Management (FEM) use cases in this Guide relate to a subset Diagnostic Imaging related document sharing requirements which were addressed by the Cross-Enterprise Document Sharing (XDS) Affinity domain and which are summarized in the XDS Affinity Domain Implementation Guide.

    Foreign Exam Management (FEM) relates to those scenarios where a health care provider organization with local Radiology Information System (RIS) and Picture Archiving and Communication System (PACS) needs to allow users to retrieve and view an “imaging exam that was ordered, acquired, and reported on at some site external to the one where the study is currently being imported.”  (IHE Import Reconciliation Workflow Supplement for Trial Implementation  

    Although existing systems provide the means to import Foreign Exams from external sources manually, the integration of local systems with shared Diagnostic Imaging Repositories (DI-R) introduces new workflows and requirements in need of standardization, including:

    • Automated import (fetching) of prior exams, and
    • Rules for local management of content which is maintained within and readily available from alternate source systems.

    Typical Use Cases

    The following requirements help frame the need for standardization to support Foreign Exam Management.  They assume integration between local RIS / PACS and a shared DI-R already exists.

    Table of Contents

    UC-1 Workflow

    The focus of FEM use cases is acquisition (“fetching”) of relevant foreign exams for display and use by health care providers during the course of a current patient encounter.  Image sets can be very large and therefore the ability to “pre-fetch” images before they are required for viewing is desired to improve user productivity. 

    The XDS Affinity Domain Implementation Guide identifies a number of use cases which are summarized here:

    UC-1.1 Pre-Fetching

    • Patient related events at the local facility trigger an automatic search for relevant prior exams on the DI-R:
      • Basic example: request related prior images when an exam is ordered, initiate query on patient arrival to radiology,
      • Non-radiology example: patient arrival at clinic (e.g. oncology, neurology) triggers search for relevant exams, or
      • Report only example: similar to examples above but return reports only.
    • Relevant image sets and reports are automatically retrieved and brought in to the local hospital system for review.
    • Information retrieved should not be archived locally as it remains available from the DI-R.

    UC-1.2 Ad-Hoc or On-Demand Image Fetch

    • A user at the local facility manually initiates a query to find existing relevant prior images for a specified patient and selects image sets of interest from a list of results.
    • Relevant image sets and reports are retrieved and brought in to the local hospital system for review.
    • Information retrieved should not be archived locally as it remains available from the DI-R.

    UC-1.3 Amendments

    • Identifies steps to replace foreign report when a report is amended after pre-fetch.
    • Identifies steps to replace an image set when an image is added or changed after pre-fetch.

    UC-1.4 Emergency Patients

    • Identifies options to use DI-R / FEM to improve workflow when patient arrives at hospital via ambulance.

    UC-2 Identification of Relevant Prior Exams

    Fetching or pre-fetching of relevant information requires consistent use of metadata to determine relevance.

    • Identifiers used to specify the acquisition modality and anatomic region of the study need to be standardized.

    UC-3 Retention of Foreign Information

    Foreign content should be identifiable within local systems and should not be archived or retained long term.

     

    Evaluated Standards

    Foreign Exam Management use cases cover three main areas requiring standardization:

    • Document and Image Sharing
    • Imaging Report Format
    • Anatomic Region Code

    Listed below are the available standards considered for each standardization category, the chosen alternative being highlighted.

    Document and Image Sharing

    Foreign Exam Management will be implemented by an organization participating a jurisdictions’ shared Diagnostic Imaging Repository (DI-R) system.  The DI-R will provide for registration and long term storage of sets of images and reports and standards based services that will be leveraged and, possibly, upgraded to support the FEM use case(s).

    Standard

    Fit for Purpose

    Stewardship

    Quality

    Fits
    Requirements

    Implementation
    Type 

    Vendor Support

    Canadian
    Steward

    SDO
    Maintained

    Complexity

    Standard
    Maturity

    Training,
    Support
    and Tooling

    IHE Cross-Enterprise Document Sharing - Imaging (XDS/XDS-I)

    Closely

    Production
    in Canada 

    High

    Yes

    Yes

    High

     

    High

    Available

    DICOM / HL7 v2 and Clinical Document Architecture (CDA)

    Partial

    Production
    in Canada 

    High

    No

    Yes

    Medium

    High

    Unknown

    Architectural Constraints and Considerations

    Secondary Benefits

    None of these standards impose significant architectural constraints

     

    Recommendation

    Supporting Rationale

    IHE Cross-Enterprise Document Sharing - Imaging (XDS/XDS-I)

    The IHE XDS-I.b profile specifies the use of existing standards including HL7 v2/CDA and DICOM to enable registration and sharing of images and reports.  A Canadian XDS Affinity domain guide is available to support implementation of the profile.

    Note:

    The IHE XDS/XDS-I profile builds upon the foundational HL7 and DICOM standards by identifying the roles of different actors participating in the information exchange and specifying how data exchange transactions and applicable standards enable document sharing.  It also prescribes an affinity domain process that was employed by the Canadian Diagnostic Imaging Community to constrain areas of optionality in the IHE XDS/XDS-I profile to Canadian requirements.  The XDS Affinity Domain Implementation Guide is the work product of this group.

    Report Format

    XDS/XDS-I supports a range of report formats through the use of different transaction and reporting

    Standard

    Fit for Purpose

    Stewardship

    Quality

    Fits
    Requirements 

    Implementation
    Type 

    Vendor
    Support 

    Canadian
    Steward 

    SDO
    Maintained 

    Complexity

    Standard
    Maturity

    Training, Support
    and Tooling

    Clinical Document Architecture (CDA) R2

    Closely

    Limited in
    Canada 

    Limited

    No

    Yes

    High

    Normative

    Some

    Portable Document Format (PDF)

    Partial

    Production
    in Canada 

    Ubiquitous

    No

    N/A

    Low

    N/A

    Available

    DICOM Structured Reporting (SR) /  Secondary Capture (SC)

    Partial

    Production
    in Canada 

    High

    No

    Yes

    Medium

    Normative

    Unknown

    Raw Text

    Limited

    Production
    in Canada 

    Unknown

    No

    No

    Low

    N/A

    Not Appliccable

    Architectural Constraints and Considerations

    Secondary Benefits

    Use of CDA document allows content to be rendered in all other formats.  Raw text based HL7 v2 ORU and DICOM SR are widely used and present in DI-R systems and require support.

    PDF may preclude secondary use, while the structured data of a CDA document supports machine readability and may enable secondary use of clinical data, clinical decision support or application of administrative/demographic data to analytics/business intelligence.

    Recommendation

    Supporting Rationale

    Clinical Document Architecture (CDA) R2

    It is the goal of the Canadian XDS Affinity domain that reports will be stored in HL7 CDA format (using the pan-Canadian header format) as these reports (a) support required metadata, and (b) can be transformed to all other formats.

    Anatomic Region Code

    Metadata plays an important role in the identification of relevant priors during the fetch and pre-fetch use cases.  The significant coded metadata elements for the FEM use case are the acquisition modality of image and the anatomical region being studied.  Acquisition modality was adopted as prescribed.

     

    Standard

    Fit for Purpose

    Stewardship

    Quality

    Fits
    Requirements 

    Implementation
    Type 

    Vendor
    Support 

    Canadian
    Stewardship

    SDO
    Maintained 

    Complexity

    Standard
    Maturity

    Training, Support
    and Tooling

    Coarse Body Parts (SNOMED CT subset)

    Closely

    Production
    in Canada 

    High (Flat List)

    No

    Yes (IHE)

    Low

    Normative

    Good

    Anatomic Region (DICOM CID 4)

    Limited

    International

    High

    No

    Yes

    Low

    Normative

    Unknown

    Architectural Constraints and Considerations

    Secondary Benefits

    Both terminology subsets referenced are published as flat lists with descriptions and codes.

    Using pan-Canadian terminology subsets supports inter-jurisdictional interoperability.  SNOMED CT’s terminology model can be leveraged to support aggregation and analysis of the information captured within vaccination records.

    Recommendation

    Supporting Rationale

    Coarse Body Parts (SNOMED CT subset)

    The DICOM CID 4 value set is very detailed and generally inconsistent with the general approach of “casting a wide net” employed when fetching content within the FEM use cases.

    Note:

    Anatomic Region was localized for Canadian use.

    Recommended Standards

    The following standards and related specifications were identified as the recommended approach to support the in-scope requirements. The table lists the summary with the rationale.

     

    Standardization Requirement

    Options

    Choice

    Rationale

    Document and Image Sharing

    IHE Cross-Enterprise Document Sharing - Imaging (XDS/XDS-I)

    X

    The IHE XDS-I.b profile specifies the use of existing standards including HL7 v2/CDA and DICOM to enable registration and sharing of images and reports.  A Canadian XDS Affinity domain guide is available to support implementation of the profile.

    DICOM / HL7 v2 and Clinical Document Architecture (CDA)

     

    Imaging Report Format

    Clinical Document Architecture (CDA) R2

    X

    It is the goal of the Canadian XDS Affinity domain that reports will be stored in HL7 CDA format (using the pan-Canadian header format) as these reports (a) support required metadata, and (b) can be transformed to all other formats.

     

    * Raw text based HL7 v2 ORU and DICOM SR are widely used and present in DI-R systems.

    Portable Document Format (PDF)

     

    DICOM SR /  SC*

     

    Raw Text*

     

    Anatomic Region Code

    Coarse Body Parts (SNOMED CT subset)

    X

    The DICOM CID 4 value set is very detailed and generally inconsistent with the general approach of “casting a wide net” employed when fetching content within the FEM use cases.

    Anatomic Region (DICOM Context Identifier/CID 4)

     

    Implementation Resources

    Community Pages

    Matters related to Foreign Exam Management in Canada are handled through an active Diagnostic Imaging Community on InfoCentral.

    InfoCentral - Community Page

     Diagnostic Imaging - Community Site

    Implementation Guides

    The latest XDS Affinity Domain Implementation Guide is available on InfoCentral.

    For further technical support please contact Canada Health Infoway.

    Existing Implementations

    The following organizations are known to have implemented the FEM solution outlined in this guide:

    Implementing OrganizationNotes
    Southwestern Ontario
    Diagnostic Imaging Network (SWODIN) 
    SWODIN did a successful FEM pilot, however, they are now moving to a large regional PACS/DI-R for LHIN 1-2-3-4 that will eliminate the need for FEM
    Hospital Diagnostic Imaging
    Repository Services (HDIRS) 
     
    Northern and Eastern Ontario
    Diagnostic Imaging Network (NEODIN)
     
    Greater Toronto Area (GTA) West