Efficient Streaming of EHR Imagery: Combining JPIP and WADO within an XDS-I Framework

1. Efficient, Standard-Compliant Streaming of EHR ImageryCombining JPIP and WADO within an XDS-I Framework Lev Weisfeiler Aware, Inc. Co-chair DICOM WG4 (Compression) DICOM to JPEG liaison www.aware.com/medical

2. The need for a standardized streaming technology is emerging as regions/countries deploy image-enabled EHR

3. Introduction – EHR, XDS-I • Many countries are implementing image-enabled EHRs • IHE XDS-I is an effective solution for publication and discovery of patient diagnostic imaging history across multiple enterprises • Physical access to data requires DICOM transfer from one PACS to another • Relatively slow due to multiple transactions and DICOM over the WAN • Complexities introduced from copying data between PACS • “ingesting foreign data” problem • DICOM configuration can become unmanageable in a regional setting • IHE XDS-I is emerging as the prevailing interoperability architecture • Some countries are promoting compliance to the IHE Profile • Some projects are not concerned about the compliance to standards, but see the profile as an effective solution to the interoperability problem

4. XDS - Overview • Objective of XDS • To support document sharing between enterprises in different care settings and organizations • XDS “Publish and Subscribe” paradigm • Create a persistent “document”… images, reports, etc. • Publish the document to the a “repository” • Register the document in an “index” • “Consumers” query the index to find out about documents and where they are stored • Consumers retrieve documents “on-demand” from the repository

5. XDS-I – Key Concepts • Users reference images at the “exam” (study) level • Users do not reference images at the “image” level • XDS-I needs to “publish” and “index” a document that represents the “exam”… not the image • Requires a level of abstraction, namely an image “manifest” • The manifest is a document with a list of pointers to the images that it represents • The manifest is a DICOM KOS object

6. Motivation - Image Streaming • To achieve access to image data within the EHR and maintain acceptable performance, projects need content delivery techniques with streaming technology • WADO is a means to address many of the DICOM related challenges in an image-enabled EHR • WADO provides HTTP-based method of access to DICOM objects • Consumers discover the URL to images through XDS-I and can thereby retrieve images via HTTP through WADO • Limit the use of DICOM to communications between modalities and PACS • JPIP offers standardized “on-demand”, streamed access to image data • Streaming technology allows fast image display over lower bandwidth networks • Standard enables any viewing client to access data from any JPIP server

7. JPIP - Overview • Standardized image streaming • JPEG 2000, Part 9 • ISO/IEC 15444-9 • ITU-T Rec. T.808 • Included in DICOM • Supplement 106 • Efficient transmission of JPEG 2000 data over varying bandwidth networks • JPEG 2000 provides high quality, DICOM-compliant, wavelet-based image compression • JPIP is the blueprint for the best usage of JPEG 2000 functionality in a distributed application environment

8. JPIP Streaming Use Cases • Stack navigation of a large CT study • Low resolution preview • Full fidelity imagery available on demand • Large single image navigation • Pan/zoom region of interest at display resolution • Thumbnail representation for a study • Sub-resolution image easily extracted • Display by dimension • Random access to individual frames of a large enhanced multiframe object

9. DICOM Access Example • Patient presents at emergency room (ER) • User requests data (through XDS-I discovery and retrieve) • Copy image data via DICOM C-MOVE • Data ingestion and preparation • Image display using local PACS proprietary protocols Consumer (ER) XDS Registry/Repository DICOM DICOM DICOM Image Manager/Archive

10. WADO/JPIP Access • Patient presents at ER • User requests data (through XDS-I discovery and retrieve) • XDS query (ITI-16) • HTTP-SOAP with SQL text • Responds with candidate documents and associated URI • XDS document retrieve (ITI-17) • HTTP transaction • Returns DICOM KOS object Consumer (ER) XDS Registry/Repository Image Manager/Archive

11. WADO/JPIP Access • Patient presents at ER • User requests data (through XDS-I discovery and retrieve) • WADO request for image data • Parse the DICOM KOS “manifest” • Extract the URI to series • WADO http GET • Use the URI from manifest to initiate a WADO Get • Define transfer syntax to be JPIP Consumer (ER) XDS Registry/Repository http GET http GET http GET Image Manager/Archive

12. WADO/JPIP Access • Patient presents at ER • User requests data (through XDS-I discovery and retrieve) • WADO request for image data • Image data streamed to viewing client using JPIP • Local PACS IM/IA supports WADO • WADO server includes JPIP server • Stream data from JPIP enabled PACS to viewing client • Viewing client supports JPIP Consumer (ER) XDS Registry/Repository Image Manager/Archive

13. Remote Viewing • Web based image viewing client • Access manifest (KOS) via WADO • Request images in manifest through WADO with a JPIP transfer syntax • Stream image data from JPIP enabled PACS to client

14. Summary - Benefits Combining XDS-I/WADO/JPIP • Standards based data discovery across multiple PACS (XDS-I) • Fast image access over WAN without the need for • DICOM configuration • DICOM transfer • Foreign data ingestion into PACS • All standard-compliant; no proprietary protocols • Leverage ubiquitous security environment • Client and servers can be from different vendors

15. Acknowledgements Thank you to Dr. Peter Bak for his contribution • The Chair of the Pan-Canadian Standards Working Group for DI • Director of architecture for DI at Canada Health Infoway • Primary author of the pan-Canadian XDS-I standard • Primary author of the “JPIP adoption as a pan-Canadian standard” initiative

16. Acronyms • IHE – Integrating the Healthcare Enterprise • EHR – Electronic Health Record • XDS-I – Cross Enterprise Document Sharing for Imaging • WADO – Web Access to DICOM Objects • JPIP – JPEG 2000 Interactive Protocol • PACS – Picture Archiving and Communication Systems • KOS - Key Object Selection • WAN – Wide Area Network