DICOM Structured Reports: Practical Introduction to Reporting Tools, Exercises of Radiology

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RSNA 2015 – RCA

A Practical Introduction to Structured

Reporting Tools and Resources

DICOM Structured Reports (SR)

David Clunie ([email protected])

PixelMed Publishing

Background & Disclosures

l Owner, PixelMed Publishing, LLC

l Radiologist

l Independent Consultant

l Sub-contractor on NCI QIICR project

l Editor of DICOM Standard

l Formerly co-chair DICOM Standards Committee

l Formerly co-chair IHE Radiology Technical

Committee

Motivation

l Utility

• e.g., extraction of measurements to use in another context, such

as automatically merging into another table, database, report or

document

l Semantic Interoperability

• standard encoding, recognizable pattern, recognizable codes

produced by different systems and consumed by different systems

l No human required

• i.e., “machine readable” without need for OCR or NLP
• beyond screen shots and “pretty pictures” or uncoded graphics

What is “structure” anyway

l “arrangement of and relations between the parts or

elements of something complex” (Oxford)

l Some or all of

• an organized outline (vs. arbitrary prose)
• controlled vocabulary/terminology (i.e., coded concepts)
• measurements related to images and regions of interest

l Distinguish:

• narrative form (+/- augmented with non-narrative content)
• structured encoding

DICOM Structured Report (SR)

l Extends the DICOM standard beyond attributes in "image

header”

l Into a “tree” of structured content

l Each tree node (“content item”) is a "name-value" pair

l Or a “container” (provides an outline of “headings”)

l Name is always coded, value may or may not be

l Generic framework - recursively nested content of unbounded

complexity

l Complexity constrained for specific use cases by "templates"

SR Content Tree 1

Child Nodes 1. 1 1.

Parent Node

Relationships

Content Item Encoding

l Container or name-value pair

l Content items have a value type

l Concept name is always coded

l Value may be text or a code depending on value type

l Codes are from external sources or defined in DICOM

l Content items are related by “relationships”

SR Content Item Value Types

l CONTAINER

l TEXT

l CODE

l NUM

l PNAME

l DATE

l TIME

l DATETIME

l UIDREF

l COMPOSITE

l IMAGE

l WAVEFORM

l SCOORD

l SCOORD3D

l TCOORD

SR Content Tree

SR Content Item Encoding 1.5.1.9: HAS ACQ CONTEXT: NUM: (110910,DCM,"Pixel Data Rows”) = 128 ({pixels},UCUM,"pixels") 1.5.1.10: HAS ACQ CONTEXT: NUM: (110911,DCM,"Pixel Data Columns”) = 128 ({pixels},UCUM,"pixels") 1.5.1.11: HAS ACQ CONTEXT: CODE: (C-10072,SRT,"Radionuclide”) = (C-111A1,SRT,"^18^Fluorine") 1.5.1.12: HAS ACQ CONTEXT: CODE: (F-61FDB,SRT,"Radiopharmaceutical agent”) = (C-B1031,SRT,"Fluorodeoxyglucose F^18^")

Encoding Codes

l A three-tuple of

• Code Value

• Coding Scheme Designator

• Code Meaning

l E.g.

• (C-B1031, SRT, "Fluorodeoxyglucose F^18^”)

Encoding Codes

l A three-tuple of

• Code Value

• Coding Scheme Designator

• Code Meaning

l E.g.

• (C-B1031, SRT, "Fluorodeoxyglucose F^18^”)

Encoding Codes

l A three-tuple of

• Code Value

• Coding Scheme Designator

• Code Meaning

l E.g.

• (C-B1031, SRT, "Fluorodeoxyglucose F^18^”)

Which Codes from Where? l SNOMED codes used by preference throughout DICOM

• long historical relationship, esp. anatomy
• agreement to allow license/fee free use in DICOM implementations
• strong desire for semantic interoperability with clinical (non-imaging) systems that use SNOMED (or UMLS)
• DICOM contributes imaging content to SNOMED l LOINC (UMLS)
• for measurements and report titles
• now has relationship with SNOMED l NCI Thesaurus (UMLS)
• especially for oncology, research and clinical trial concepts not in SNOMED l Foundational Model of Anatomy (UMLS) and NeuroNames
• occasional anatomic concepts not in SNOMED (there is a SNOMED-FMA harmonization activity) l RadLex
• occasional radiology-specific concepts not in other schemes l DICOM defined codes (“DCM”, in DICOM PS3.16)
• for imaging-specific not appropriate for (or not yet added to) other schemes