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Supplement 155 Imaging Reports using HL7 CDA. Status Report to WG-06 2014/04/01 Harry Solomon. Goals. Foundational architecture for an evolving family of imaging reports Initial templates for radiology reports, aligned with RSNA RadLex and Reporting Initiative
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Supplement 155Imaging Reports using HL7 CDA Status Report to WG-06 2014/04/01 Harry Solomon
Goals • Foundational architecture for an evolving family of imaging reports • Initial templates for radiology reports, aligned with RSNA RadLex and Reporting Initiative • Primarily narrative, with some discrete data; evolving to more discrete data over time • Diagnostic and screening; evolving to interventional, cardiac, anatomic path, etc. Sup 155 review
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
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; allows document management, compilation of an individual patient's clinical documents into an electronic patient record Body contains narrative text / multimedia content (level 1), optionally structured into sections with coded titles and tagged narrative content (level 2), optionally augmented by coded equivalents to narrative (level 3) CDA documents for a particular use may be constrained by a Template Key Aspects of the CDA
Core concepts of RIM • Every happening is an Act • Procedure, observation, medication, supply, registration, etc. • Acts are related through an ActRelationship • composition, preconditions, revisions, support, etc. • Participation defines involvement in an Act • author, performer, subject, location, etc. • The participants are Roles • patient, agent, responsible party. • Roles are played and scoped by Entities • persons, organizations, material, places, devices, etc.
RIM Classes and Color Coding Plays Source 0..* 0..* Entity Role Participation Act Relation-ship Act 0..* 1 0..1 0..1 0..* 1 0..* 1 0..1 1 Scopes Target A person … Mr Joe Public … … an observation Asthma … … playing the role patient … … which is the Reason for … … participates as the subject of … … an administration of albuterol…
CDA Release 2 Information Model Header Body Start Here Participants Doc ID &Type Context Sections/Headings Clinical Statements/ Coded Entries Extl Refs
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 Entry Coded statement
CDA structured body requireshuman-readable “Narrative Block”, all that is needed to reproduce the legally attested clinical content CDA allows optionalmachine-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 Narrative and Coded Info
Purposes of templates • Reduce variability, improve interoperability • Normalize best practice • Support automation of report production • Support validation of report content Sup 155 review
Multiple layers of constraint • Professional Content • Specific content for specialized procedures • DICOM (Sup 155) • Additional requirements andtemplates for radiology reports CDA r2 Refined Data Classes and structures for clinical documents HL7 v3 RIM Abstract Data Classes Sup 155 review
Sup 155 as greenCDA • greenCDAis the concept that CDA implementation can be simplified by abstractions bridging between use cases and CDA formal syntax requirements • Defines data elements, using “business names”, that can be invoked by professional content specifications, without knowledge of CDA structures • E.g., professional content can specify “impression:text”, or “contrast:name” and “contrast:volume”, and Sup 155 specifies how/where those are instantiated in a CDA structure Sup 155 review
CDA Report Instance Templates Authoring Template Element Structure Element Public Interface Element CDA Structure IHE MRRT Report Authoring Template Clinical Knowledge RSNA RadReport Report Formatting Process Report Authoring Process CDA Imaging Report Document Imaging Study Data Clinician Interpretation Sup 155 review
Sup 155 editorial style • Following conventions of HL7 CDA implementation guides, including Consolidated CDA, and emerging HL7 Templates Standard (in ballot reconciliation) • Library of document, section, and entry templates • Templates specified as table aligned to XML, plus supplemental narrative conformance statements (conceptually similar to Part 3 module style) • XML examples provided • Not being generated from tooling (MDHT or Trifolia) Sup 155 review
Radiology Report Document Template Sup 155 review
Subsections • Some defined in templates for specific uses • Contrast, Radiation Dose, Fetus Finding • Requirements for user-labeled subsections • Content for an arbitrary topic (a particular organ or anatomic feature, a lesion, a tumor, etc.) • Required section.titlewith topic name • No section.code, hence no semantic post-coordination to section entries Sup 155 review
Why no section.codein user-labeled subsection? • section.code uses LOINC codes with scale=NAR • i.e., its value in section.text is a narrative block • A concept that scopes a value (observable entity) • The concepts used as user-labels (typically anatomy) are the wrong “part of speech” • Do not have formal semantics of scoping a value • Need something like a post-coordinated phrase:FindingsSection+FindingSite=<anatomy> (cf. DICOM) • CDA does not have section targetSiteCode or Participation for anatomic site Sup 155 review
External Relations • HL7 • RSNA • Radiology Reporting • RadLex • IHE • MRRT
Relationship to HL7 • Builds on HL7 Diagnostic Imaging Report (DIR) CDA IG informative standard • Leverages harmonization done for Consolidated CDA IG r2 (C-CDA) • Public comment to be solicited in HL7 ballot cycle parallel to DICOM PC and LB periods • May be balloted as HL7 standard (DIR r2), recognizing updates will be handled in DICOM continuous maintenance process Sup 155 review
Reuse of C-CDA Templates • Intent is to be harmonized with C-CDA • But C-CDA is US Realm only – DICOM needs to be Universal Realm • Challenges to re-use based on shortcuts taken • Vocabulary bindings hard coded into templates • Vocabulary bindings US Realm only Sup 155 review
RSNA Reporting Initiative radreport.org Sup 155 review
CT Brain (example) Clinical History * Medical history * Risk factors * Allergies, if relevant * Reason for exam, including medical necessity: [headache | stroke | dizziness | trauma] Imaging Technique * Time of image acquisition * Imaging device [MR, CT] * Image acquisition parameters, such as device settings, patient positioning, interventions (e.g., Valsalva) * Contrast materials and other medications administered (including name, dose, route, and time) * Radiation dose Comparison * Date and type of previous exams reviewed, if applicable Observations * Extra axial spaces: [normal in size and morphology for the patient's age* | widened] * Hemorrhage: [none* ; subdural ; subarachnoid; epidural, intraventricular, parenchymal] * Ventricular system: [normal in size and morphology for the patient's age* | enlarged | small] * Basal cisterns: [normal* | enlarged | small] * Cerebral parenchyma: [normal*; microvascular changes; infarction; encephalomalacia; gliosis; hemorrhage] * Midline shift: [none* | leftward shift | rightward shift] … Impressions
RadLex tagged content • RadLex is an RSNA lexicon designed to tag concepts for subsequent indexing/retrieval • Atomic concepts only – no compositional grammar • Use CDA <linkHtml>non-attested link in narrative block <section> ... <text> ...<content>There is focal opacity at the right lung base most likely representing right lower lobe atelectasis.<linkHtml href=http://www.radlex.org/RID/RID1302 /><linkHtml href=http://www.radlex.org/RID/RID28493 /> </content></text> ... </section> Sup 155 review
Relationship to IHE MRRT • Management of Radiology Report Templates is an IHE Profile that (inter alia) defines an HTML scheme for encoding report production templates • Revisions needed for MRRT to use DICOM defined business names, supporting encoding of reports as CDA using Sup 155 • Informative annex in DICOM about use of templates in report production, including MRRT • Should we invite IHE Radiology to submit revised HTML scheme for standardization in Sup 155? Sup 155 review
DICOM Stuff Sup 155 review
What about Part 20? • Designed for mapping SR to CDA • Includes CDA structures also used in Sup 155 templates (e.g., DICOM Object Catalog, header structures, image references, etc.) • Suggest general reworking combining current Part 20 with new material in Sup 155, to produce a replacement Part 20 • How to handle new version of current Part 20 material? Sup 155 review
Conformance • What needs to specified in Part 2 with respect to conformance? • Creator claim of document level templates • That would just be one, for now • How about specific uses and/or RSNA templates? • No expected receiver claims beyond general HL7 CDA receiver conformance • Not intended to be in the DICOM conformance world Sup 155 review
Schedule • April 1: WG-06 – review overall strategy • May-Jun: WG-06 webinars for line by line review • Jun 23-27: WG-06 –Release for PC • Mid July-mid Sept: Public Comment • Sept 8-12: WG-06 – review comments and necessary revisions • Nov 10-14: WG-06 – Release for LB • Nov-Jan: Letter Ballot • Jan 12-16: WG-06 – Final Text Draft • ?? Publish FT • May 5-9: HL7 – review with Structured Documents WG, and “clean draft” Supplement • Aug 8-Sep 8: HL7 Comment Only ballot • Sep 15-19: HL7 – review comments • Dec 12-Jan 12:HL7 Comment Only ballot • Jan 19-23: HL7 – review comments and Final Text Draft Sup 155 review
Should Sup155 be DSTU? • DICOM generally has not found DSTU to be useful • HL7 uses it regularly, especially for CDA IG’s Sup 155 review