Daniel J. Vreeman, PT, DPT, MScAssociate Research Professor, Indiana University School of Medicine

Associate Director for Terminology Services, Regenstrief Institute, Inc

2014

LOINC and RELMA for Diagnostic Imaging

Canada Health Infoway, Standards Collaborative Working Group 10 for Diagnostic Imaging

Overview

1. Welcome to LOINC

2. LOINC Radiology Model (How we name imaging studies)

3. Tools for implementers

4. Use Case Samples

5. Collaborations: RSNA, IHTSDO (if needed)

photo via Vernio77

photo via jamescridland

Welcome to the LOINC Community!

LogicalObservationIdentifiersNames andCodes

A universal code system that facilitates exchange, pooling, and processing of clinical data.

LOINC is like a bar code for test data

34,000+ registered users in 163 countries

photo via puuikibeach

WE DO MEASUREMENTS

Laboratory LOINC

Clinical LOINC

If an observation is a question and the observation value is an answer

LOINC provides codes for questionsWhere needed, other vocabularies provide codes for answers

LOINC Diagnostic Imaging (Radiology)

photo via Karen Roe

In diagnostic imaging, LOINC provides codes for: !

Ordered (and returned) imaging study

Sections within a report

Measurements or observations made

Update to CCDA currently in revision at HL7

Diagnostic Imaging ReportStructure from:

Document Level CodesAbdomen CT

Brain MRI W & WO Contrast IV

Orbit X-ray for foreign body

This is our bread and butter

Radiology Report Terms

Modality # LOINC TermsCT 716

Mammography 145

MRI 854

Nuclear Medicine 455

Ultrasound 442

XR 1858

Fluoroscopy 646

> 5000 active terms

Sections within a Report18785-6 Reason for study

55108-5 Clinical presentation

55111-9 Current imaging procedure descriptions

11329-0 History general

18782-3 Study observation (Findings)

55107-7 Addendum

55109-3 Complications

55114-3 Prior imaging procedure descriptions

55113-5 Key images

19005-8 Impressions

18834-2 Comparison study

18783-1 Recommendation

55115-0 Requested imaging studies information

55112-7 Document summary

55110-1 Conclusions

Measurements / Observations38261-4 Hip DXA Bone density

38264-8 Hip DXA [T-score] Bone density

53626-8 CT Cerebral atrophic index

8294-1 Chest XR Diameter.anterior-posterior

In other domains, this is LOINCs main content

Radiology Naming ModelFirst some general principles

Multiple Levels of SpecificityViews

named, counted, no specification

Laterality

right, left, bilateral, unilateral, unspecified

Contrast

W, WO, W&WO, unspecified

37842-2:View AP:Find:Pt:Shoulder:Doc:XR

37842-2 LOINC Code

View AP

Find

Pt

Shoulder

Doc

XR

Component

Property Measured

Timing

System

Scale

Method

There are six major LOINC axes

Anatomy of a LOINC Term

NOT part of a LOINC NameReason for the test (disease it diagnoses)

Testing instrument

Specific details about the testing

Priority (e.g. STAT)

Where testing was done

Who did the test

Test interpretation

Anything not part of naming the test

Stuff carried in other parts of HL7 message

Radiology Naming ModelRadiology-specific conventions

Component Structure 1st Subpart - View

Views descriptor Views, Multisection, Views for leg length ,

# of views 3, greater than 3

Beam orientation AP, lateral

Body position Prone

[] [] []

Component Structure 1st Subpart - Interventional

Timing/existence W, W&WO, 48H post

Substance given contrast, adenosine, Tc-99m Sestamibi

Route IV, PO

Guidance for

Component Structure 2nd Subpart - Challenge/Precondition

Examples !

Guidance for biopsy:Find:Pt:Breast:Nar:Mam

Guidance for anesthetic block injection:Find:Pt:Celiac plexus:Nar:CT

Guidance for drainage:Find:Pt:Extremity:Nar:US

System

The anatomic area being visualized

Not necessarily the anatomic area of interest

!

Examples 24627-2 Chest CT

24590-2 Brain MRI

25011-8 Tibia and Fibula X-ray

System Structure

Super System Patient is the default Used to indicate: blood product unit, bone marrow donor, fetus

11670-7:Blood ow.mean:Vel:Pt:Aortic arch^fetus:Qn:US.doppler

System^Super System

Method Modality

Modality CT, MRI, XR

Submodality angio, fluor, SPECT

Side note: we handle ographies as synonyms. (e.g. arthrogram is linked to W contrast intraarticular

Tools for Implementers

photo via Robert S Donovan

RELMAREgenstrief LOINC Mapping Assistant

RELMA Features

Browse LOINC content

!

Map local terms to LOINC import/export translate local words to LOINC-speak manual/automated mapping

Search Window

Mapping Screen

navigate through your local term sethit enter to run a search

Assigning a LOINC Map

Highlight the correct LOINC

Assign a map (or double click)

search.loinc.orgonline LOINC browser

search.loinc.org

Use Case SamplesTaken from September 16, 2014 Terminology assessment example

Modalities

Recommendation LOINC doesnt have discrete codes for modalities.

(They are the Method Part of a LOINC term).

!

Hint Find codes with modality of ultrasound using method:US in searches

!Here is a code for a generic ultrasound study that doesnt specify any particular views or the exact body region

!

Ultrasound

25061-3:Multisection:Find:Pt:XXX:Doc:US

Other Pieces of LOINC namesLaterality

Part of the Anatomic specification. Shoulder.left

Hint: In RELMA you can exclude these.

!

Contrast / Intervention

Anatomic Region / Body Parts

Procedures

Recommendation Procedures are where LOINC shines. These are what the 5000+ radiology terms in LOINC are meant for.

!

Hint Here is a code for a typical OB ultrasound study

!

Obstetrical Ultrasound

11525-3:Multisection for pregnancy:Find:Pt:Pelvis+Fetus:Doc:US

Reason for Exam

Recommendation Recall that LOINC provides codes for questions (observations/measurements). So, LOINC has a code that represents the question what is the reason for the exam:

!!The expected answers would be free text or drawn from another terminology like SNOMED CT. Often though, you dont need a LOINC code for this observation, because the information is sent in field OBR-31 Reason for Study. LOINC doesnt have a code that means confirm 20 week gestational age.

confirm 20 week gestational age

18785-6:Reason for study:Find:Pt:Report:Nar:Radiology

Clinical Findings/Diagnosis

Recommendation

There are a few ways to get BPD. Heres a code for a direct measurement:

!

!

Likewise for head circumference. Heres a measured one:

!

!

But, LOINC does not have a code for the diagnosis microcephaly. (That would come from SNOMED CT).

US Bi-parietal Diameter, Head Circumference

11820-8:Diameter.biparietal:Len:Pt:Head^fetus:Qn:US.measured

11984-2:Perimeter:Len:Pt:Head^fetus:Qn:US.measured

LOINC / RadLex Collaboration

RadLex PlaybookA special component of RadLex

Developed by RSNA

Information model tailored for radiology orders and results, and connected to other terms in RadLex (e.g., anatomy, visual features).

!

RadLex is made freely available for private, research, and commercial use internationally.

http://loinc.org/collaboration/rsna/

Overall Goal:Produce a single unified source of names and codes for radiology procedures with a cooperative governance process.

Main DeliverablesDeveloping a Unified Model for Radiology Procedure Names

!

Mapping the attribute-values between each terminology (i.e. LOINC Parts to RadLex RPIDs)

!

Main DeliverablesDevising collaborative integrated governance process for new terms

!

Creating single point-of-contact and governance structure for the unified terminology

!New joint LOINC/RadLex Committee to be advisory body (Approved at Clinical LOINC Meeting 02/2014)

!LOINC codes as the primary identifier for radiology procedures (e.g. the universal codes) while linking to the RadLex attribute/values for each term so that they can be used as meta-data

LOINC / SNOMED Collaboration

http://loinc.org/collaboration/ihtsdo

Key PointsIts NOT a merger, take-over It IS a long term working relationship !

Endorsed statement: LOINC for questions, SNOMED for answers

!

We want to avoid duplication LOINC Parts not a standalone terminology Not adding SNOMED CT Observables

4 Main DeliverablesMapping LOINC Parts to SNOMED CT concepts

!

Mapping existing SNOMED CT Observables to LOINC terms

!

LOINC terms associated with post-coordinated expressions

!

LOINC terms with categorical answer values linked to SNOMED CT answers

How Well ProceedAgreement starts with these domain areas

Laboratory Including discrete orders and observations and panel names for orders (excluding panel structure)

Anthropomorphic measurements and evaluations

Vital signs and physiological measurements

!

Agreement says we expect (but have not yet committed to) to expand into other observable domains (such as Radiology)