The Radiology Playbook: A Missing Component of RadLex™ Nasya Mendoza-Elias and Lizhou Huang Pat Mongkolwat, Ph.D. and David S. Channin, M.D. Northwestern University Feinberg School of Medicine DePaul University College of Computing and Digital Media National Science Foundation Research Experience for Undergraduates In Medical Informatics Program August 21, 2008

Overview Introduction Progress Future Work

What is RadLex™? Funded by the Radiological Society of North America (RSNA) Purpose  Capturing  Indexing  Retrieving Will unify other lexicons

What is the RadLex™Playbook? Orders, procedures, and procedure steps Powered by an ontology Dynamic

Why do we need a Playbook? Consistency Interoperability Inadequacy of other lexicons

What about Common Procedural Terminology CPT™? Not an adequate description  Radiologic examination, chest; single view, frontal  Radiologic examination, chest; stereo, frontal  Radiologic examination, chest, two views, frontal and lateral  Radiologic examination, chest, two views, frontal and lateral; with apical lordotic  Radiologic examination, chest, two views, frontal and lateral; with oblique  Radiologic examination, chest, two views, frontal and lateral; with fluoroscopy  Radiologic examination, chest, complete, minimum of four views  Radiologic examination, chest, complete, minimum of four views; with fluoroscopy  Radiologic examination, chest, special views (eg, lateral decubitus, Bucky studies)

Whereas Merrill’s Atlas of Radiographic Positioning and Radiologic Procedures says:

The IHE Model Order Placer System: orderable Order Filler: orderable  procedures Order Filler: procedure steps via modality worklist

So… Orderable  Referring physician Requested Procedure(s)  Radiologist  Reportable, codifiable, billable unit of work Procedure Step  Technologist (modality)  Scheduled procedure steps  Performed procedure steps

The Challenge Treading the fine line of granularity between the needs of the referring physician and the detail of radiology operations

What will the RadLex™ Playbook deliver initially? Knowledge model Grammar  Set of orderable names Grammar for imaging and non-imaging procedure steps  A set of procedure step names  Can be used in DICOM

What can you do with the Playbook? Build a chargemaster Protocol studies Tailor studies Build software applications with “knowledge”

What’s been keeping us busy Ontology structure GUI Query  Filtering of choices

Ontologies What is an ontology?  Concepts and relationships  For example Wine: An alcoholic beverage fermented from grapes Red Wine: Wine fermented from whole grapes  is_a wine  color: red White wine: Wine fermented from skinless grapes  is_a wine  color: white Chardonnay is_a white wine Bordeaux is_a red wine Allows for knowledge based computation:  “Is Chardonnay a wine?”

For example… Paranasal Sinus 1. Survey 2. SAG T1 SE 3. COR SE T1 4. COR T2 TSE 5. AX SE T1 6. AX T2 TSE 7. INJECT 8. AX SHARP FS 9. COR SHARP FS 10. SAG SHARP FS NMH-HEAD_47 1. MR FACE MP SCOUT 2. MR FACE SAG T1R-2D(SE_1)_N 3. MR FACE COR T1R-2D(SE_1)_N 4. MR FACE COR T2P-2D(SE_N)_N/M 5. MR FACE AX T1R-2D(SE_1)_N 6. MR FACE AX T2P-2D(SE_N)_N/M 7. MR FACE INJ GAD 8. MR FACE AX 2D(GRE_1)_N 9. MR FACE COR 2D(GRE_1)_N 10. MR FACE SAG 2D(GRE_1)_N

Translation –CT, DEXA, Fluoro, Mammo, X-Ray Use RadLex Categorize procedure steps by attributes

Knowledge Model Example XRAY CHEST is_a Imaging Orderable XRAY CHEST has_steps 1. XRAY CHEST PA XRAY CHEST PA is_a XRAY Procedure Step XRAY CHEST PA has_projection CORONAL XRAY CHEST PA produces DICOM DX Object 2. XRAY CHEST LATERAL LEFT XRAY CHEST LATERAL LEFT is_a XRAY Procedure Step XRAY CHEST LATERAL LEFT has_projection SAGGITAL XRAY CHEST LATERAL LEFT produces DICOM DX Object

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Name Rest. 1Rest. 2Rest. 3Rest. 4Rest. 5

Procedure Step

User Interface Query based on a series of restrictions Restriction filters are mutually linked Restrictors can be applied in any order

GUI (July 18)

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Querying the Ontology Code by Kaustubh Supekar, Stanford, created for a different project Surprisingly roundabout code  a.txt  Deletes everything that is not a result

Problems with the query Slow  Requires vast amounts of code  Loads ontology for every query

Future Work Connecting all parts of the GUI with the query Optimizing the query  Strip unnecessary code  Load ontology once

Future Work Realtime web interface Modifying ontology Authorization and administration Integration into RadLex Other features

Such as… Exporting protocols Printing Searching for similar protocols

Thank you Questions?